[PATCH v6 7/7] net: Suppress the "Comparison to NULL could be written" warnings
This is to suppress the checkpatch.pl warning "Comparison to NULL
could be written". No functional changes here.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv4/proc.c | 32
net/sctp/proc.c | 2 +-
2 files changed, 17 insertions(+), 17 deletions(-)
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 9d7a39a..b39faf6 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -357,22 +357,22 @@ static void icmp_put(struct seq_file *seq)
atomic_long_t *ptr = net->mib.icmpmsg_statistics->mibs;
seq_puts(seq, "\nIcmp: InMsgs InErrors InCsumErrors");
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " In%s", icmpmibmap[i].name);
seq_puts(seq, " OutMsgs OutErrors");
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " Out%s", icmpmibmap[i].name);
seq_printf(seq, "\nIcmp: %lu %lu %lu",
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INMSGS),
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INERRORS),
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_CSUMERRORS));
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " %lu",
atomic_long_read(ptr + icmpmibmap[i].index));
seq_printf(seq, " %lu %lu",
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTMSGS),
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTERRORS));
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " %lu",
atomic_long_read(ptr + (icmpmibmap[i].index |
0x100)));
}
@@ -389,7 +389,7 @@ static int snmp_seq_show_ipstats(struct seq_file *seq, void
*v)
memset(buff64, 0, IPSTATS_MIB_MAX * sizeof(u64));
seq_puts(seq, "Ip: Forwarding DefaultTTL");
- for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
+ for (i = 0; snmp4_ipstats_list[i].name; i++)
seq_printf(seq, " %s", snmp4_ipstats_list[i].name);
seq_printf(seq, "\nIp: %d %d",
@@ -400,7 +400,7 @@ static int snmp_seq_show_ipstats(struct seq_file *seq, void
*v)
snmp_get_cpu_field64_batch(buff64, snmp4_ipstats_list,
net->mib.ip_statistics,
offsetof(struct ipstats_mib, syncp));
- for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
+ for (i = 0; snmp4_ipstats_list[i].name; i++)
seq_printf(seq, " %llu", buff64[i]);
return 0;
@@ -415,13 +415,13 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq,
void *v)
memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
seq_puts(seq, "\nTcp:");
- for (i = 0; snmp4_tcp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_tcp_list[i].name; i++)
seq_printf(seq, " %s", snmp4_tcp_list[i].name);
seq_puts(seq, "\nTcp:");
snmp_get_cpu_field_batch(buff, snmp4_tcp_list,
net->mib.tcp_statistics);
- for (i = 0; snmp4_tcp_list[i].name != NULL; i++) {
+ for (i = 0; snmp4_tcp_list[i].name; i++) {
/* MaxConn field is signed, RFC 2012 */
if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN)
seq_printf(seq, " %ld", buff[i]);
@@ -434,10 +434,10 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq,
void *v)
snmp_get_cpu_field_batch(buff, snmp4_udp_list,
net->mib.udp_statistics);
seq_puts(seq, "\nUdp:");
- for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_udp_list[i].name; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
seq_puts(seq, "\nUdp:");
- for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_udp_list[i].name; i++)
seq_printf(seq, " %lu", buff[i]);
memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
@@ -446,10 +446,10 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq,
void *v)
seq_puts(seq, "\nUdpLite:");
snmp_get_cpu_field_batch(buff, snmp4_udp_list,
net->mib.udplite_statistics);
- for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_udp_list[i].name; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
seq_puts(seq, "\nUdpLite:");
- for (i = 0; snmp4_u
[PATCH v6 1/7] net:snmp: Introduce generic interfaces for snmp_get_cpu_field{,64}
This is to introduce the generic interfaces for snmp_get_cpu_field{,64}.
It exchanges the two for-loops for collecting the percpu statistics data.
This can aggregate the data by going through all the items of each cpu
sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
Suggested-by: Marcelo Ricardo Leitner <marcelo.leit...@gmail.com>
---
include/net/ip.h | 23 +++
1 file changed, 23 insertions(+)
diff --git a/include/net/ip.h b/include/net/ip.h
index 9742b92..bc43c0f 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -219,6 +219,29 @@ static inline u64 snmp_fold_field64(void __percpu *mib,
int offt, size_t syncp_o
}
#endif
+#define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
+{ \
+ int i, c; \
+ for_each_possible_cpu(c) { \
+ for (i = 0; stats_list[i].name; i++) \
+ buff64[i] += snmp_get_cpu_field64( \
+ mib_statistic, \
+ c, stats_list[i].entry, \
+ offset); \
+ } \
+}
+
+#define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
+{ \
+ int i, c; \
+ for_each_possible_cpu(c) { \
+ for (i = 0; stats_list[i].name; i++) \
+ buff[i] += snmp_get_cpu_field( \
+ mib_statistic, \
+ c, stats_list[i].entry); \
+ } \
+}
+
void inet_get_local_port_range(struct net *net, int *low, int *high);
#ifdef CONFIG_SYSCTL
--
2.5.5
[PATCH v6 5/7] proc: Reduce cache miss in xfrm_statistics_seq_show
This is to use the generic interfaces snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/xfrm/xfrm_proc.c | 10 --
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/net/xfrm/xfrm_proc.c b/net/xfrm/xfrm_proc.c
index 9c4fbd8..ba2b539 100644
--- a/net/xfrm/xfrm_proc.c
+++ b/net/xfrm/xfrm_proc.c
@@ -50,12 +50,18 @@ static const struct snmp_mib xfrm_mib_list[] = {
static int xfrm_statistics_seq_show(struct seq_file *seq, void *v)
{
+ unsigned long buff[LINUX_MIB_XFRMMAX];
struct net *net = seq->private;
int i;
+
+ memset(buff, 0, sizeof(unsigned long) * LINUX_MIB_XFRMMAX);
+
+ snmp_get_cpu_field_batch(buff, xfrm_mib_list,
+net->mib.xfrm_statistics);
for (i = 0; xfrm_mib_list[i].name; i++)
seq_printf(seq, "%-24s\t%lu\n", xfrm_mib_list[i].name,
- snmp_fold_field(net->mib.xfrm_statistics,
- xfrm_mib_list[i].entry));
+ buff[i]);
+
return 0;
}
--
2.5.5
[PATCH v6 4/7] proc: Reduce cache miss in sctp_snmp_seq_show
This is to use the generic interfaces snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/sctp/proc.c | 8 ++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/net/sctp/proc.c b/net/sctp/proc.c
index ef8ba77..09e16c2 100644
--- a/net/sctp/proc.c
+++ b/net/sctp/proc.c
@@ -73,13 +73,17 @@ static const struct snmp_mib sctp_snmp_list[] = {
/* Display sctp snmp mib statistics(/proc/net/sctp/snmp). */
static int sctp_snmp_seq_show(struct seq_file *seq, void *v)
{
+ unsigned long buff[SCTP_MIB_MAX];
struct net *net = seq->private;
int i;
+ memset(buff, 0, sizeof(unsigned long) * SCTP_MIB_MAX);
+
+ snmp_get_cpu_field_batch(buff, sctp_snmp_list,
+net->sctp.sctp_statistics);
for (i = 0; sctp_snmp_list[i].name != NULL; i++)
seq_printf(seq, "%-32s\t%ld\n", sctp_snmp_list[i].name,
- snmp_fold_field(net->sctp.sctp_statistics,
- sctp_snmp_list[i].entry));
+ buff[i]);
return 0;
}
--
2.5.5
[PATCH v6 2/7] proc: Reduce cache miss in snmp_seq_show
This is to use the generic interfaces snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Then snmp_seq_show is split into 2 parts to avoid build warning "the frame
size" larger than 1024.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv4/proc.c | 70 ++---
1 file changed, 47 insertions(+), 23 deletions(-)
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 9f665b6..9d7a39a 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -46,6 +46,8 @@
#include
#include
+#define TCPUDP_MIB_MAX max_t(u32, UDP_MIB_MAX, TCP_MIB_MAX)
+
/*
* Report socket allocation statistics [m...@utu.fi]
*/
@@ -378,13 +380,15 @@ static void icmp_put(struct seq_file *seq)
/*
* Called from the PROCfs module. This outputs /proc/net/snmp.
*/
-static int snmp_seq_show(struct seq_file *seq, void *v)
+static int snmp_seq_show_ipstats(struct seq_file *seq, void *v)
{
- int i;
struct net *net = seq->private;
+ u64 buff64[IPSTATS_MIB_MAX];
+ int i;
- seq_puts(seq, "Ip: Forwarding DefaultTTL");
+ memset(buff64, 0, IPSTATS_MIB_MAX * sizeof(u64));
+ seq_puts(seq, "Ip: Forwarding DefaultTTL");
for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_ipstats_list[i].name);
@@ -393,57 +397,77 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
net->ipv4.sysctl_ip_default_ttl);
BUILD_BUG_ON(offsetof(struct ipstats_mib, mibs) != 0);
+ snmp_get_cpu_field64_batch(buff64, snmp4_ipstats_list,
+ net->mib.ip_statistics,
+ offsetof(struct ipstats_mib, syncp));
for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
- seq_printf(seq, " %llu",
- snmp_fold_field64(net->mib.ip_statistics,
-snmp4_ipstats_list[i].entry,
-offsetof(struct ipstats_mib,
syncp)));
+ seq_printf(seq, " %llu", buff64[i]);
- icmp_put(seq); /* RFC 2011 compatibility */
- icmpmsg_put(seq);
+ return 0;
+}
+
+static int snmp_seq_show_tcp_udp(struct seq_file *seq, void *v)
+{
+ unsigned long buff[TCPUDP_MIB_MAX];
+ struct net *net = seq->private;
+ int i;
+
+ memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
seq_puts(seq, "\nTcp:");
for (i = 0; snmp4_tcp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_tcp_list[i].name);
seq_puts(seq, "\nTcp:");
+ snmp_get_cpu_field_batch(buff, snmp4_tcp_list,
+net->mib.tcp_statistics);
for (i = 0; snmp4_tcp_list[i].name != NULL; i++) {
/* MaxConn field is signed, RFC 2012 */
if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN)
- seq_printf(seq, " %ld",
- snmp_fold_field(net->mib.tcp_statistics,
- snmp4_tcp_list[i].entry));
+ seq_printf(seq, " %ld", buff[i]);
else
- seq_printf(seq, " %lu",
- snmp_fold_field(net->mib.tcp_statistics,
- snmp4_tcp_list[i].entry));
+ seq_printf(seq, " %lu", buff[i]);
}
+ memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
+
+ snmp_get_cpu_field_batch(buff, snmp4_udp_list,
+net->mib.udp_statistics);
seq_puts(seq, "\nUdp:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
-
seq_puts(seq, "\nUdp:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
- seq_printf(seq, " %lu",
- snmp_fold_field(net->mib.udp_statistics,
- snmp4_udp_list[i].entry));
+ seq_printf(seq, " %lu", buff[i]);
+
+ memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
/* the UDP and UDP-Lite MIBs are the same */
seq_puts(seq, "\nUdpLite:");
+ snmp_get_cpu_field_batch(buff, snmp4_udp_list,
+net->mib.udplite_statistics);
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
-
seq_puts(seq, "\nUdpLite:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
- seq_printf(seq, " %lu"
[PATCH v6 3/7] proc: Reduce cache miss in snmp6_seq_show
This is to use the generic interfaces snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv6/proc.c | 30 ++
1 file changed, 22 insertions(+), 8 deletions(-)
diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c
index 679253d0..cc8e3ae 100644
--- a/net/ipv6/proc.c
+++ b/net/ipv6/proc.c
@@ -30,6 +30,11 @@
#include
#include
+#define MAX4(a, b, c, d) \
+ max_t(u32, max_t(u32, a, b), max_t(u32, c, d))
+#define SNMP_MIB_MAX MAX4(UDP_MIB_MAX, TCP_MIB_MAX, \
+ IPSTATS_MIB_MAX, ICMP_MIB_MAX)
+
static int sockstat6_seq_show(struct seq_file *seq, void *v)
{
struct net *net = seq->private;
@@ -191,25 +196,34 @@ static void snmp6_seq_show_item(struct seq_file *seq,
void __percpu *pcpumib,
atomic_long_t *smib,
const struct snmp_mib *itemlist)
{
+ unsigned long buff[SNMP_MIB_MAX];
int i;
- unsigned long val;
- for (i = 0; itemlist[i].name; i++) {
- val = pcpumib ?
- snmp_fold_field(pcpumib, itemlist[i].entry) :
- atomic_long_read(smib + itemlist[i].entry);
- seq_printf(seq, "%-32s\t%lu\n", itemlist[i].name, val);
+ if (pcpumib) {
+ memset(buff, 0, sizeof(unsigned long) * SNMP_MIB_MAX);
+
+ snmp_get_cpu_field_batch(buff, itemlist, pcpumib);
+ for (i = 0; itemlist[i].name; i++)
+ seq_printf(seq, "%-32s\t%lu\n",
+ itemlist[i].name, buff[i]);
+ } else {
+ for (i = 0; itemlist[i].name; i++)
+ seq_printf(seq, "%-32s\t%lu\n", itemlist[i].name,
+ atomic_long_read(smib + itemlist[i].entry));
}
}
static void snmp6_seq_show_item64(struct seq_file *seq, void __percpu *mib,
const struct snmp_mib *itemlist, size_t
syncpoff)
{
+ u64 buff64[SNMP_MIB_MAX];
int i;
+ memset(buff64, 0, sizeof(unsigned long) * SNMP_MIB_MAX);
+
+ snmp_get_cpu_field64_batch(buff64, itemlist, mib, syncpoff);
for (i = 0; itemlist[i].name; i++)
- seq_printf(seq, "%-32s\t%llu\n", itemlist[i].name,
- snmp_fold_field64(mib, itemlist[i].entry, syncpoff));
+ seq_printf(seq, "%-32s\t%llu\n", itemlist[i].name, buff64[i]);
}
static int snmp6_seq_show(struct seq_file *seq, void *v)
--
2.5.5
[PATCH v6 6/7] ipv6: Remove useless parameter in __snmp6_fill_statsdev
The parameter items(is always ICMP6_MIB_MAX) is useless for
__snmp6_fill_statsdev
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv6/addrconf.c | 12 ++--
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 2f1f5d4..35d4baa 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4961,18 +4961,18 @@ static inline size_t inet6_if_nlmsg_size(void)
}
static inline void __snmp6_fill_statsdev(u64 *stats, atomic_long_t *mib,
- int items, int bytes)
+ int bytes)
{
int i;
- int pad = bytes - sizeof(u64) * items;
+ int pad = bytes - sizeof(u64) * ICMP6_MIB_MAX;
BUG_ON(pad < 0);
/* Use put_unaligned() because stats may not be aligned for u64. */
- put_unaligned(items, [0]);
- for (i = 1; i < items; i++)
+ put_unaligned(ICMP6_MIB_MAX, [0]);
+ for (i = 1; i < ICMP6_MIB_MAX; i++)
put_unaligned(atomic_long_read([i]), [i]);
- memset([items], 0, pad);
+ memset([ICMP6_MIB_MAX], 0, pad);
}
static inline void __snmp6_fill_stats64(u64 *stats, void __percpu *mib,
@@ -5005,7 +5005,7 @@ static void snmp6_fill_stats(u64 *stats, struct inet6_dev
*idev, int attrtype,
offsetof(struct ipstats_mib, syncp));
break;
case IFLA_INET6_ICMP6STATS:
- __snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs,
ICMP6_MIB_MAX, bytes);
+ __snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs,
bytes);
break;
}
}
--
2.5.5
[PATCH v6 0/7] Reduce cache miss for snmp_fold_field
In a PowerPc server with large cpu number(160), besides commit
a3a773726c9f ("net: Optimize snmp stat aggregation by walking all
the percpu data at once"), I watched several other snmp_fold_field
callsites which would cause high cache miss rate.
test source code:
My simple test case, which read from the procfs items endlessly:
/***/
#include
#include
#include
#include
#include
#define LINELEN 2560
int main(int argc, char **argv)
{
int i;
int fd = -1 ;
int rdsize = 0;
char buf[LINELEN+1];
buf[LINELEN] = 0;
memset(buf,0,LINELEN);
if(1 >= argc) {
printf("file name empty\n");
return -1;
}
fd = open(argv[1], O_RDWR, 0644);
if(0 > fd){
printf("open error\n");
return -2;
}
for(i=0;i<0x;i++) {
while(0 < (rdsize = read(fd,buf,LINELEN))){
//nothing here
}
lseek(fd, 0, SEEK_SET);
}
close(fd);
return 0;
}
/**/
compile and run:
gcc test.c -o test
perf stat -d -e cache-misses ./test /proc/net/snmp
perf stat -d -e cache-misses ./test /proc/net/snmp6
perf stat -d -e cache-misses ./test /proc/net/sctp/snmp
perf stat -d -e cache-misses ./test /proc/net/xfrm_stat
before the patch set:
Performance counter stats for 'system wide':
355911097 cache-misses
[40.08%]
2356829300 L1-dcache-loads
[60.04%]
355642645 L1-dcache-load-misses # 15.09% of all L1-dcache
hits [60.02%]
346544541 LLC-loads
[59.97%]
389763 LLC-load-misses #0.11% of all LL-cache
hits[40.02%]
6.245162638 seconds time elapsed
After the patch set:
===
Performance counter stats for 'system wide':
194992476 cache-misses
[40.03%]
6718051877 L1-dcache-loads
[60.07%]
194871921 L1-dcache-load-misses #2.90% of all L1-dcache
hits [60.11%]
187632232 LLC-loads
[60.04%]
464466 LLC-load-misses #0.25% of all LL-cache
hits[39.89%]
6.868422769 seconds time elapsed
The cache-miss rate can be reduced from 15% to 2.9%
changelog
=
v6:
- correct v5
v5:
- order local variables from longest to shortest line
v4:
- move memset into one block of if statement in snmp6_seq_show_item
- remove the changes in netstat_seq_show considerred the stack usage is too
large
v3:
- introduce generic interface (suggested by Marcelo Ricardo Leitner)
- use max_t instead of self defined macro (suggested by David Miller)
v2:
- fix bug in udplite statistics.
- snmp_seq_show is split into 2 parts
Jia He (7):
net:snmp: Introduce generic interfaces for snmp_get_cpu_field{,64}
proc: Reduce cache miss in snmp_seq_show
proc: Reduce cache miss in snmp6_seq_show
proc: Reduce cache miss in sctp_snmp_seq_show
proc: Reduce cache miss in xfrm_statistics_seq_show
ipv6: Remove useless parameter in __snmp6_fill_statsdev
net: Suppress the "Comparison to NULL could be written" warnings
include/net/ip.h | 23
net/ipv4/proc.c | 102 +++
net/ipv6/addrconf.c | 12 +++---
net/ipv6/proc.c | 30 +++
net/sctp/proc.c | 10 +++--
net/xfrm/xfrm_proc.c | 10 -
6 files changed, 129 insertions(+), 58 deletions(-)
--
2.5.5
[PATCH v5 6/7] ipv6: Remove useless parameter in __snmp6_fill_statsdev
The parameter items(always ICMP6_MIB_MAX) is useless for __snmp6_fill_statsdev.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv6/addrconf.c | 12 ++--
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 2f1f5d4..35d4baa 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4961,18 +4961,18 @@ static inline size_t inet6_if_nlmsg_size(void)
}
static inline void __snmp6_fill_statsdev(u64 *stats, atomic_long_t *mib,
- int items, int bytes)
+ int bytes)
{
int i;
- int pad = bytes - sizeof(u64) * items;
+ int pad = bytes - sizeof(u64) * ICMP6_MIB_MAX;
BUG_ON(pad < 0);
/* Use put_unaligned() because stats may not be aligned for u64. */
- put_unaligned(items, [0]);
- for (i = 1; i < items; i++)
+ put_unaligned(ICMP6_MIB_MAX, [0]);
+ for (i = 1; i < ICMP6_MIB_MAX; i++)
put_unaligned(atomic_long_read([i]), [i]);
- memset([items], 0, pad);
+ memset([ICMP6_MIB_MAX], 0, pad);
}
static inline void __snmp6_fill_stats64(u64 *stats, void __percpu *mib,
@@ -5005,7 +5005,7 @@ static void snmp6_fill_stats(u64 *stats, struct inet6_dev
*idev, int attrtype,
offsetof(struct ipstats_mib, syncp));
break;
case IFLA_INET6_ICMP6STATS:
- __snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs,
ICMP6_MIB_MAX, bytes);
+ __snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs,
bytes);
break;
}
}
--
2.5.5
[PATCH v5 5/7] proc: Reduce cache miss in xfrm_statistics_seq_show
This is to use the generic interfaces snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/xfrm/xfrm_proc.c | 12 +---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/net/xfrm/xfrm_proc.c b/net/xfrm/xfrm_proc.c
index 9c4fbd8..dc0cea6 100644
--- a/net/xfrm/xfrm_proc.c
+++ b/net/xfrm/xfrm_proc.c
@@ -50,12 +50,18 @@ static const struct snmp_mib xfrm_mib_list[] = {
static int xfrm_statistics_seq_show(struct seq_file *seq, void *v)
{
- struct net *net = seq->private;
int i;
+ struct net *net = seq->private;
+ unsigned long buff[LINUX_MIB_XFRMMAX];
+
+ memset(buff, 0, sizeof(unsigned long) * LINUX_MIB_XFRMMAX);
+
+ snmp_get_cpu_field_batch(buff, xfrm_mib_list,
+net->mib.xfrm_statistics);
for (i = 0; xfrm_mib_list[i].name; i++)
seq_printf(seq, "%-24s\t%lu\n", xfrm_mib_list[i].name,
- snmp_fold_field(net->mib.xfrm_statistics,
- xfrm_mib_list[i].entry));
+ buff[i]);
+
return 0;
}
--
2.5.5
[PATCH v5 1/7] net:snmp: Introduce generic interfaces for snmp_get_cpu_field{,64}
This is to introduce the generic interfaces for snmp_get_cpu_field{,64}.
It exchanges the two for-loops for collecting the percpu statistics data.
This can aggregate the data by going through all the items of each cpu
sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
Suggested-by: Marcelo Ricardo Leitner <marcelo.leit...@gmail.com>
---
include/net/ip.h | 23 +++
1 file changed, 23 insertions(+)
diff --git a/include/net/ip.h b/include/net/ip.h
index 9742b92..bc43c0f 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -219,6 +219,29 @@ static inline u64 snmp_fold_field64(void __percpu *mib,
int offt, size_t syncp_o
}
#endif
+#define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
+{ \
+ int i, c; \
+ for_each_possible_cpu(c) { \
+ for (i = 0; stats_list[i].name; i++) \
+ buff64[i] += snmp_get_cpu_field64( \
+ mib_statistic, \
+ c, stats_list[i].entry, \
+ offset); \
+ } \
+}
+
+#define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
+{ \
+ int i, c; \
+ for_each_possible_cpu(c) { \
+ for (i = 0; stats_list[i].name; i++) \
+ buff[i] += snmp_get_cpu_field( \
+ mib_statistic, \
+ c, stats_list[i].entry); \
+ } \
+}
+
void inet_get_local_port_range(struct net *net, int *low, int *high);
#ifdef CONFIG_SYSCTL
--
2.5.5
[PATCH v5 3/7] proc: Reduce cache miss in snmp6_seq_show
This is to use the generic interfaces snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv6/proc.c | 32 +++-
1 file changed, 23 insertions(+), 9 deletions(-)
diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c
index 679253d0..e047701 100644
--- a/net/ipv6/proc.c
+++ b/net/ipv6/proc.c
@@ -30,6 +30,11 @@
#include
#include
+#define MAX4(a, b, c, d) \
+ max_t(u32, max_t(u32, a, b), max_t(u32, c, d))
+#define SNMP_MIB_MAX MAX4(UDP_MIB_MAX, TCP_MIB_MAX, \
+ IPSTATS_MIB_MAX, ICMP_MIB_MAX)
+
static int sockstat6_seq_show(struct seq_file *seq, void *v)
{
struct net *net = seq->private;
@@ -192,13 +197,19 @@ static void snmp6_seq_show_item(struct seq_file *seq,
void __percpu *pcpumib,
const struct snmp_mib *itemlist)
{
int i;
- unsigned long val;
-
- for (i = 0; itemlist[i].name; i++) {
- val = pcpumib ?
- snmp_fold_field(pcpumib, itemlist[i].entry) :
- atomic_long_read(smib + itemlist[i].entry);
- seq_printf(seq, "%-32s\t%lu\n", itemlist[i].name, val);
+ unsigned long buff[SNMP_MIB_MAX];
+
+ if (pcpumib) {
+ memset(buff, 0, sizeof(unsigned long) * SNMP_MIB_MAX);
+
+ snmp_get_cpu_field_batch(buff, itemlist, pcpumib);
+ for (i = 0; itemlist[i].name; i++)
+ seq_printf(seq, "%-32s\t%lu\n",
+ itemlist[i].name, buff[i]);
+ } else {
+ for (i = 0; itemlist[i].name; i++)
+ seq_printf(seq, "%-32s\t%lu\n", itemlist[i].name,
+ atomic_long_read(smib + itemlist[i].entry));
}
}
@@ -206,10 +217,13 @@ static void snmp6_seq_show_item64(struct seq_file *seq,
void __percpu *mib,
const struct snmp_mib *itemlist, size_t
syncpoff)
{
int i;
+ u64 buff64[SNMP_MIB_MAX];
+
+ memset(buff64, 0, sizeof(unsigned long) * SNMP_MIB_MAX);
+ snmp_get_cpu_field64_batch(buff64, itemlist, mib, syncpoff);
for (i = 0; itemlist[i].name; i++)
- seq_printf(seq, "%-32s\t%llu\n", itemlist[i].name,
- snmp_fold_field64(mib, itemlist[i].entry, syncpoff));
+ seq_printf(seq, "%-32s\t%llu\n", itemlist[i].name, buff64[i]);
}
static int snmp6_seq_show(struct seq_file *seq, void *v)
--
2.5.5
[PATCH v5 7/7] net: Suppress the "Comparison to NULL could be written" warnings
This is to suppress the checkpatch.pl warning "Comparison to NULL
could be written". No functional changes here.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv4/proc.c | 32
net/sctp/proc.c | 2 +-
2 files changed, 17 insertions(+), 17 deletions(-)
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index e01f4df..1a7a773 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -357,22 +357,22 @@ static void icmp_put(struct seq_file *seq)
atomic_long_t *ptr = net->mib.icmpmsg_statistics->mibs;
seq_puts(seq, "\nIcmp: InMsgs InErrors InCsumErrors");
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " In%s", icmpmibmap[i].name);
seq_puts(seq, " OutMsgs OutErrors");
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " Out%s", icmpmibmap[i].name);
seq_printf(seq, "\nIcmp: %lu %lu %lu",
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INMSGS),
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INERRORS),
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_CSUMERRORS));
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " %lu",
atomic_long_read(ptr + icmpmibmap[i].index));
seq_printf(seq, " %lu %lu",
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTMSGS),
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTERRORS));
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " %lu",
atomic_long_read(ptr + (icmpmibmap[i].index |
0x100)));
}
@@ -389,7 +389,7 @@ static int snmp_seq_show_ipstats(struct seq_file *seq, void
*v)
memset(buff64, 0, IPSTATS_MIB_MAX * sizeof(u64));
seq_puts(seq, "Ip: Forwarding DefaultTTL");
- for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
+ for (i = 0; snmp4_ipstats_list[i].name; i++)
seq_printf(seq, " %s", snmp4_ipstats_list[i].name);
seq_printf(seq, "\nIp: %d %d",
@@ -400,7 +400,7 @@ static int snmp_seq_show_ipstats(struct seq_file *seq, void
*v)
snmp_get_cpu_field64_batch(buff64, snmp4_ipstats_list,
net->mib.ip_statistics,
offsetof(struct ipstats_mib, syncp));
- for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
+ for (i = 0; snmp4_ipstats_list[i].name; i++)
seq_printf(seq, " %llu", buff64[i]);
return 0;
@@ -415,13 +415,13 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq,
void *v)
memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
seq_puts(seq, "\nTcp:");
- for (i = 0; snmp4_tcp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_tcp_list[i].name; i++)
seq_printf(seq, " %s", snmp4_tcp_list[i].name);
seq_puts(seq, "\nTcp:");
snmp_get_cpu_field_batch(buff, snmp4_tcp_list,
net->mib.tcp_statistics);
- for (i = 0; snmp4_tcp_list[i].name != NULL; i++) {
+ for (i = 0; snmp4_tcp_list[i].name; i++) {
/* MaxConn field is signed, RFC 2012 */
if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN)
seq_printf(seq, " %ld", buff[i]);
@@ -434,10 +434,10 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq,
void *v)
snmp_get_cpu_field_batch(buff, snmp4_udp_list,
net->mib.udp_statistics);
seq_puts(seq, "\nUdp:");
- for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_udp_list[i].name; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
seq_puts(seq, "\nUdp:");
- for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_udp_list[i].name; i++)
seq_printf(seq, " %lu", buff[i]);
memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
@@ -446,10 +446,10 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq,
void *v)
seq_puts(seq, "\nUdpLite:");
snmp_get_cpu_field_batch(buff, snmp4_udp_list,
net->mib.udplite_statistics);
- for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_udp_list[i].name; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
seq_puts(seq, "\nUdpLite:");
- for (i = 0; snmp4_u
[PATCH v5 4/7] proc: Reduce cache miss in sctp_snmp_seq_show
This is to use the generic interfaces snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/sctp/proc.c | 10 +++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/net/sctp/proc.c b/net/sctp/proc.c
index ef8ba77..9e7f4a7 100644
--- a/net/sctp/proc.c
+++ b/net/sctp/proc.c
@@ -73,13 +73,17 @@ static const struct snmp_mib sctp_snmp_list[] = {
/* Display sctp snmp mib statistics(/proc/net/sctp/snmp). */
static int sctp_snmp_seq_show(struct seq_file *seq, void *v)
{
- struct net *net = seq->private;
int i;
+ struct net *net = seq->private;
+ unsigned long buff[SCTP_MIB_MAX];
+
+ memset(buff, 0, sizeof(unsigned long) * SCTP_MIB_MAX);
+ snmp_get_cpu_field_batch(buff, sctp_snmp_list,
+net->sctp.sctp_statistics);
for (i = 0; sctp_snmp_list[i].name != NULL; i++)
seq_printf(seq, "%-32s\t%ld\n", sctp_snmp_list[i].name,
- snmp_fold_field(net->sctp.sctp_statistics,
- sctp_snmp_list[i].entry));
+ buff[i]);
return 0;
}
--
2.5.5
[PATCH v5 0/7] Reduce cache miss for snmp_fold_field
In a PowerPc server with large cpu number(160), besides commit
a3a773726c9f ("net: Optimize snmp stat aggregation by walking all
the percpu data at once"), I watched several other snmp_fold_field
callsites which would cause high cache miss rate.
test source code:
My simple test case, which read from the procfs items endlessly:
/***/
#include
#include
#include
#include
#include
#define LINELEN 2560
int main(int argc, char **argv)
{
int i;
int fd = -1 ;
int rdsize = 0;
char buf[LINELEN+1];
buf[LINELEN] = 0;
memset(buf,0,LINELEN);
if(1 >= argc) {
printf("file name empty\n");
return -1;
}
fd = open(argv[1], O_RDWR, 0644);
if(0 > fd){
printf("open error\n");
return -2;
}
for(i=0;i<0x;i++) {
while(0 < (rdsize = read(fd,buf,LINELEN))){
//nothing here
}
lseek(fd, 0, SEEK_SET);
}
close(fd);
return 0;
}
/**/
compile and run:
gcc test.c -o test
perf stat -d -e cache-misses ./test /proc/net/snmp
perf stat -d -e cache-misses ./test /proc/net/snmp6
perf stat -d -e cache-misses ./test /proc/net/sctp/snmp
perf stat -d -e cache-misses ./test /proc/net/xfrm_stat
before the patch set:
Performance counter stats for 'system wide':
355911097 cache-misses
[40.08%]
2356829300 L1-dcache-loads
[60.04%]
355642645 L1-dcache-load-misses # 15.09% of all L1-dcache
hits [60.02%]
346544541 LLC-loads
[59.97%]
389763 LLC-load-misses #0.11% of all LL-cache
hits[40.02%]
6.245162638 seconds time elapsed
After the patch set:
===
Performance counter stats for 'system wide':
194992476 cache-misses
[40.03%]
6718051877 L1-dcache-loads
[60.07%]
194871921 L1-dcache-load-misses #2.90% of all L1-dcache
hits [60.11%]
187632232 LLC-loads
[60.04%]
464466 LLC-load-misses #0.25% of all LL-cache
hits[39.89%]
6.868422769 seconds time elapsed
The cache-miss rate can be reduced from 15% to 2.9%
changelog
=
v5:
- order local variables from longest to shortest line
v4:
- move memset into one block of if statement in snmp6_seq_show_item
- remove the changes in netstat_seq_show considerred the stack usage is too
large
v3:
- introduce generic interface (suggested by Marcelo Ricardo Leitner)
- use max_t instead of self defined macro (suggested by David Miller)
v2:
- fix bug in udplite statistics.
- snmp_seq_show is split into 2 parts
Jia He (7):
net:snmp: Introduce generic interfaces for snmp_get_cpu_field{,64}
proc: Reduce cache miss in snmp_seq_show
proc: Reduce cache miss in snmp6_seq_show
proc: Reduce cache miss in sctp_snmp_seq_show
proc: Reduce cache miss in xfrm_statistics_seq_show
ipv6: Remove useless parameter in __snmp6_fill_statsdev
net: Suppress the "Comparison to NULL could be written" warnings
include/net/ip.h | 23
net/ipv4/proc.c | 100 +++
net/ipv6/addrconf.c | 12 +++
net/ipv6/proc.c | 32 -
net/sctp/proc.c | 12 ---
net/xfrm/xfrm_proc.c | 12 +--
6 files changed, 131 insertions(+), 60 deletions(-)
--
2.5.5
[PATCH v5 2/7] proc: Reduce cache miss in snmp_seq_show
This is to use the generic interfaces snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Then snmp_seq_show is split into 2 parts to avoid build warning "the frame
size" larger than 1024.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv4/proc.c | 68 ++---
1 file changed, 46 insertions(+), 22 deletions(-)
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 9f665b6..e01f4df 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -46,6 +46,8 @@
#include
#include
+#define TCPUDP_MIB_MAX max_t(u32, UDP_MIB_MAX, TCP_MIB_MAX)
+
/*
* Report socket allocation statistics [m...@utu.fi]
*/
@@ -378,13 +380,15 @@ static void icmp_put(struct seq_file *seq)
/*
* Called from the PROCfs module. This outputs /proc/net/snmp.
*/
-static int snmp_seq_show(struct seq_file *seq, void *v)
+static int snmp_seq_show_ipstats(struct seq_file *seq, void *v)
{
int i;
+ u64 buff64[IPSTATS_MIB_MAX];
struct net *net = seq->private;
- seq_puts(seq, "Ip: Forwarding DefaultTTL");
+ memset(buff64, 0, IPSTATS_MIB_MAX * sizeof(u64));
+ seq_puts(seq, "Ip: Forwarding DefaultTTL");
for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_ipstats_list[i].name);
@@ -393,57 +397,77 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
net->ipv4.sysctl_ip_default_ttl);
BUILD_BUG_ON(offsetof(struct ipstats_mib, mibs) != 0);
+ snmp_get_cpu_field64_batch(buff64, snmp4_ipstats_list,
+ net->mib.ip_statistics,
+ offsetof(struct ipstats_mib, syncp));
for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
- seq_printf(seq, " %llu",
- snmp_fold_field64(net->mib.ip_statistics,
-snmp4_ipstats_list[i].entry,
-offsetof(struct ipstats_mib,
syncp)));
+ seq_printf(seq, " %llu", buff64[i]);
- icmp_put(seq); /* RFC 2011 compatibility */
- icmpmsg_put(seq);
+ return 0;
+}
+
+static int snmp_seq_show_tcp_udp(struct seq_file *seq, void *v)
+{
+ int i;
+ struct net *net = seq->private;
+ unsigned long buff[TCPUDP_MIB_MAX];
+
+ memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
seq_puts(seq, "\nTcp:");
for (i = 0; snmp4_tcp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_tcp_list[i].name);
seq_puts(seq, "\nTcp:");
+ snmp_get_cpu_field_batch(buff, snmp4_tcp_list,
+net->mib.tcp_statistics);
for (i = 0; snmp4_tcp_list[i].name != NULL; i++) {
/* MaxConn field is signed, RFC 2012 */
if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN)
- seq_printf(seq, " %ld",
- snmp_fold_field(net->mib.tcp_statistics,
- snmp4_tcp_list[i].entry));
+ seq_printf(seq, " %ld", buff[i]);
else
- seq_printf(seq, " %lu",
- snmp_fold_field(net->mib.tcp_statistics,
- snmp4_tcp_list[i].entry));
+ seq_printf(seq, " %lu", buff[i]);
}
+ memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
+
+ snmp_get_cpu_field_batch(buff, snmp4_udp_list,
+net->mib.udp_statistics);
seq_puts(seq, "\nUdp:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
-
seq_puts(seq, "\nUdp:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
- seq_printf(seq, " %lu",
- snmp_fold_field(net->mib.udp_statistics,
- snmp4_udp_list[i].entry));
+ seq_printf(seq, " %lu", buff[i]);
+
+ memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
/* the UDP and UDP-Lite MIBs are the same */
seq_puts(seq, "\nUdpLite:");
+ snmp_get_cpu_field_batch(buff, snmp4_udp_list,
+net->mib.udplite_statistics);
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
-
seq_puts(seq, "\nUdpLite:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
- seq_printf(seq, " %lu",
-
[PATCH v4 0/7] Reduce cache miss for snmp_fold_field
In a PowerPc server with large cpu number(160), besides commit
a3a773726c9f ("net: Optimize snmp stat aggregation by walking all
the percpu data at once"), I watched several other snmp_fold_field
callsites which would cause high cache miss rate.
Testcase:
=
My simple test case, which read from the procfs items endlessly:
/***/
#include
#include
#include
#include
#include
#define LINELEN 2560
int main(int argc, char **argv)
{
int i;
int fd = -1 ;
int rdsize = 0;
char buf[LINELEN+1];
buf[LINELEN] = 0;
memset(buf,0,LINELEN);
if(1 >= argc) {
printf("file name empty\n");
return -1;
}
fd = open(argv[1], O_RDWR, 0644);
if(0 > fd){
printf("open error\n");
return -2;
}
for(i=0;i<0x;i++) {
while(0 < (rdsize = read(fd,buf,LINELEN))){
//nothing here
}
lseek(fd, 0, SEEK_SET);
}
close(fd);
return 0;
}
/**/
Compile and run:
gcc test.c -o test
perf stat -d -e cache-misses ./test /proc/net/snmp
perf stat -d -e cache-misses ./test /proc/net/snmp6
perf stat -d -e cache-misses ./test /proc/net/sctp/snmp
perf stat -d -e cache-misses ./test /proc/net/xfrm_stat
before the patch set:
Performance counter stats for 'system wide':
355911097 cache-misses
[40.08%]
2356829300 L1-dcache-loads
[60.04%]
355642645 L1-dcache-load-misses # 15.09% of all L1-dcache
hits [60.02%]
346544541 LLC-loads
[59.97%]
389763 LLC-load-misses #0.11% of all LL-cache
hits[40.02%]
6.245162638 seconds time elapsed
After the patch set:
===
Performance counter stats for 'system wide':
194992476 cache-misses
[40.03%]
6718051877 L1-dcache-loads
[60.07%]
194871921 L1-dcache-load-misses #2.90% of all L1-dcache
hits [60.11%]
187632232 LLC-loads
[60.04%]
464466 LLC-load-misses #0.25% of all LL-cache
hits[39.89%]
6.868422769 seconds time elapsed
The cache-miss rate can be reduced from 15% to 2.9%
v4:
- move memset into one block of if statement in snmp6_seq_show_item
- remove the changes in netstat_seq_show considerred the stack usage is too
large
v3:
- introduce generic interface (suggested by Marcelo Ricardo Leitner)
- use max_t instead of self defined macro (suggested by David Miller)
v2:
- fix bug in udplite statistics.
- snmp_seq_show is split into 2 parts
Jia He (7):
net:snmp: Introduce generic interfaces for snmp_get_cpu_field{,64}
proc: Reduce cache miss in snmp_seq_show
proc: Reduce cache miss in snmp6_seq_show
proc: Reduce cache miss in sctp_snmp_seq_show
proc: Reduce cache miss in xfrm_statistics_seq_show
ipv6: Remove useless parameter in __snmp6_fill_statsdev
net: Suppress the "Comparison to NULL could be written" warnings
include/net/ip.h | 23
net/ipv4/proc.c | 100 +++
net/ipv6/addrconf.c | 12 +++
net/ipv6/proc.c | 32 -
net/sctp/proc.c | 10 --
net/xfrm/xfrm_proc.c | 10 --
6 files changed, 129 insertions(+), 58 deletions(-)
--
2.5.5
[PATCH v4 6/7] ipv6: Remove useless parameter in __snmp6_fill_statsdev
The parameter items(always ICMP6_MIB_MAX) is useless for __snmp6_fill_statsdev.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv6/addrconf.c | 12 ++--
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 2f1f5d4..35d4baa 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4961,18 +4961,18 @@ static inline size_t inet6_if_nlmsg_size(void)
}
static inline void __snmp6_fill_statsdev(u64 *stats, atomic_long_t *mib,
- int items, int bytes)
+ int bytes)
{
int i;
- int pad = bytes - sizeof(u64) * items;
+ int pad = bytes - sizeof(u64) * ICMP6_MIB_MAX;
BUG_ON(pad < 0);
/* Use put_unaligned() because stats may not be aligned for u64. */
- put_unaligned(items, [0]);
- for (i = 1; i < items; i++)
+ put_unaligned(ICMP6_MIB_MAX, [0]);
+ for (i = 1; i < ICMP6_MIB_MAX; i++)
put_unaligned(atomic_long_read([i]), [i]);
- memset([items], 0, pad);
+ memset([ICMP6_MIB_MAX], 0, pad);
}
static inline void __snmp6_fill_stats64(u64 *stats, void __percpu *mib,
@@ -5005,7 +5005,7 @@ static void snmp6_fill_stats(u64 *stats, struct inet6_dev
*idev, int attrtype,
offsetof(struct ipstats_mib, syncp));
break;
case IFLA_INET6_ICMP6STATS:
- __snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs,
ICMP6_MIB_MAX, bytes);
+ __snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs,
bytes);
break;
}
}
--
2.5.5
[PATCH v4 5/7] proc: Reduce cache miss in xfrm_statistics_seq_show
This is to use the generic interface snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/xfrm/xfrm_proc.c | 10 --
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/net/xfrm/xfrm_proc.c b/net/xfrm/xfrm_proc.c
index 9c4fbd8..2b280fc 100644
--- a/net/xfrm/xfrm_proc.c
+++ b/net/xfrm/xfrm_proc.c
@@ -52,10 +52,16 @@ static int xfrm_statistics_seq_show(struct seq_file *seq,
void *v)
{
struct net *net = seq->private;
int i;
+ unsigned long buff[LINUX_MIB_XFRMMAX];
+
+ memset(buff, 0, sizeof(unsigned long) * LINUX_MIB_XFRMMAX);
+
+ snmp_get_cpu_field_batch(buff, xfrm_mib_list,
+net->mib.xfrm_statistics);
for (i = 0; xfrm_mib_list[i].name; i++)
seq_printf(seq, "%-24s\t%lu\n", xfrm_mib_list[i].name,
- snmp_fold_field(net->mib.xfrm_statistics,
- xfrm_mib_list[i].entry));
+ buff[i]);
+
return 0;
}
--
2.5.5
[PATCH v4 4/7] proc: Reduce cache miss in sctp_snmp_seq_show
This is to use the generic interface snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/sctp/proc.c | 8 ++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/net/sctp/proc.c b/net/sctp/proc.c
index ef8ba77..0487c01 100644
--- a/net/sctp/proc.c
+++ b/net/sctp/proc.c
@@ -75,11 +75,15 @@ static int sctp_snmp_seq_show(struct seq_file *seq, void *v)
{
struct net *net = seq->private;
int i;
+ unsigned long buff[SCTP_MIB_MAX];
+ memset(buff, 0, sizeof(unsigned long) * SCTP_MIB_MAX);
+
+ snmp_get_cpu_field_batch(buff, sctp_snmp_list,
+net->sctp.sctp_statistics);
for (i = 0; sctp_snmp_list[i].name != NULL; i++)
seq_printf(seq, "%-32s\t%ld\n", sctp_snmp_list[i].name,
- snmp_fold_field(net->sctp.sctp_statistics,
- sctp_snmp_list[i].entry));
+ buff[i]);
return 0;
}
--
2.5.5
[PATCH v4 3/7] proc: Reduce cache miss in snmp6_seq_show
This is to use the generic interface snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv6/proc.c | 32 +++-
1 file changed, 23 insertions(+), 9 deletions(-)
diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c
index 679253d0..e047701 100644
--- a/net/ipv6/proc.c
+++ b/net/ipv6/proc.c
@@ -30,6 +30,11 @@
#include
#include
+#define MAX4(a, b, c, d) \
+ max_t(u32, max_t(u32, a, b), max_t(u32, c, d))
+#define SNMP_MIB_MAX MAX4(UDP_MIB_MAX, TCP_MIB_MAX, \
+ IPSTATS_MIB_MAX, ICMP_MIB_MAX)
+
static int sockstat6_seq_show(struct seq_file *seq, void *v)
{
struct net *net = seq->private;
@@ -192,13 +197,19 @@ static void snmp6_seq_show_item(struct seq_file *seq,
void __percpu *pcpumib,
const struct snmp_mib *itemlist)
{
int i;
- unsigned long val;
-
- for (i = 0; itemlist[i].name; i++) {
- val = pcpumib ?
- snmp_fold_field(pcpumib, itemlist[i].entry) :
- atomic_long_read(smib + itemlist[i].entry);
- seq_printf(seq, "%-32s\t%lu\n", itemlist[i].name, val);
+ unsigned long buff[SNMP_MIB_MAX];
+
+ if (pcpumib) {
+ memset(buff, 0, sizeof(unsigned long) * SNMP_MIB_MAX);
+
+ snmp_get_cpu_field_batch(buff, itemlist, pcpumib);
+ for (i = 0; itemlist[i].name; i++)
+ seq_printf(seq, "%-32s\t%lu\n",
+ itemlist[i].name, buff[i]);
+ } else {
+ for (i = 0; itemlist[i].name; i++)
+ seq_printf(seq, "%-32s\t%lu\n", itemlist[i].name,
+ atomic_long_read(smib + itemlist[i].entry));
}
}
@@ -206,10 +217,13 @@ static void snmp6_seq_show_item64(struct seq_file *seq,
void __percpu *mib,
const struct snmp_mib *itemlist, size_t
syncpoff)
{
int i;
+ u64 buff64[SNMP_MIB_MAX];
+
+ memset(buff64, 0, sizeof(unsigned long) * SNMP_MIB_MAX);
+ snmp_get_cpu_field64_batch(buff64, itemlist, mib, syncpoff);
for (i = 0; itemlist[i].name; i++)
- seq_printf(seq, "%-32s\t%llu\n", itemlist[i].name,
- snmp_fold_field64(mib, itemlist[i].entry, syncpoff));
+ seq_printf(seq, "%-32s\t%llu\n", itemlist[i].name, buff64[i]);
}
static int snmp6_seq_show(struct seq_file *seq, void *v)
--
2.5.5
[PATCH v4 7/7] net: Suppress the "Comparison to NULL could be written" warnings
This is to suppress the checkpatch.pl warning "Comparison to NULL
could be written". No functional changes here.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv4/proc.c | 32
net/sctp/proc.c | 2 +-
2 files changed, 17 insertions(+), 17 deletions(-)
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index cb04589..1ccd1b2 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -357,22 +357,22 @@ static void icmp_put(struct seq_file *seq)
atomic_long_t *ptr = net->mib.icmpmsg_statistics->mibs;
seq_puts(seq, "\nIcmp: InMsgs InErrors InCsumErrors");
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " In%s", icmpmibmap[i].name);
seq_puts(seq, " OutMsgs OutErrors");
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " Out%s", icmpmibmap[i].name);
seq_printf(seq, "\nIcmp: %lu %lu %lu",
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INMSGS),
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INERRORS),
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_CSUMERRORS));
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " %lu",
atomic_long_read(ptr + icmpmibmap[i].index));
seq_printf(seq, " %lu %lu",
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTMSGS),
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTERRORS));
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " %lu",
atomic_long_read(ptr + (icmpmibmap[i].index |
0x100)));
}
@@ -389,7 +389,7 @@ static int snmp_seq_show_ipstats(struct seq_file *seq, void
*v)
memset(buff64, 0, IPSTATS_MIB_MAX * sizeof(u64));
seq_puts(seq, "Ip: Forwarding DefaultTTL");
- for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
+ for (i = 0; snmp4_ipstats_list[i].name; i++)
seq_printf(seq, " %s", snmp4_ipstats_list[i].name);
seq_printf(seq, "\nIp: %d %d",
@@ -400,7 +400,7 @@ static int snmp_seq_show_ipstats(struct seq_file *seq, void
*v)
snmp_get_cpu_field64_batch(buff64, snmp4_ipstats_list,
net->mib.ip_statistics,
offsetof(struct ipstats_mib, syncp));
- for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
+ for (i = 0; snmp4_ipstats_list[i].name; i++)
seq_printf(seq, " %llu", buff64[i]);
return 0;
@@ -415,13 +415,13 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq,
void *v)
memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
seq_puts(seq, "\nTcp:");
- for (i = 0; snmp4_tcp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_tcp_list[i].name; i++)
seq_printf(seq, " %s", snmp4_tcp_list[i].name);
seq_puts(seq, "\nTcp:");
snmp_get_cpu_field_batch(buff, snmp4_tcp_list,
net->mib.tcp_statistics);
- for (i = 0; snmp4_tcp_list[i].name != NULL; i++) {
+ for (i = 0; snmp4_tcp_list[i].name; i++) {
/* MaxConn field is signed, RFC 2012 */
if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN)
seq_printf(seq, " %ld", buff[i]);
@@ -434,10 +434,10 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq,
void *v)
snmp_get_cpu_field_batch(buff, snmp4_udp_list,
net->mib.udp_statistics);
seq_puts(seq, "\nUdp:");
- for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_udp_list[i].name; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
seq_puts(seq, "\nUdp:");
- for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_udp_list[i].name; i++)
seq_printf(seq, " %lu", buff[i]);
memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
@@ -446,10 +446,10 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq,
void *v)
seq_puts(seq, "\nUdpLite:");
snmp_get_cpu_field_batch(buff, snmp4_udp_list,
net->mib.udplite_statistics);
- for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_udp_list[i].name; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
seq_puts(seq, "\nUdpLite:");
- for (i = 0; snmp4_u
[PATCH v4 1/7] net:snmp: Introduce generic interfaces for snmp_get_cpu_field{,64}
This is to introduce the generic interfaces for snmp_get_cpu_field{,64}.
It exchanges the two for-loops for collecting the percpu statistics data.
This can aggregate the data by going through all the items of each cpu
sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
Suggested-by: Marcelo Ricardo Leitner <marcelo.leit...@gmail.com>
---
include/net/ip.h | 23 +++
1 file changed, 23 insertions(+)
diff --git a/include/net/ip.h b/include/net/ip.h
index 9742b92..bc43c0f 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -219,6 +219,29 @@ static inline u64 snmp_fold_field64(void __percpu *mib,
int offt, size_t syncp_o
}
#endif
+#define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
+{ \
+ int i, c; \
+ for_each_possible_cpu(c) { \
+ for (i = 0; stats_list[i].name; i++) \
+ buff64[i] += snmp_get_cpu_field64( \
+ mib_statistic, \
+ c, stats_list[i].entry, \
+ offset); \
+ } \
+}
+
+#define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
+{ \
+ int i, c; \
+ for_each_possible_cpu(c) { \
+ for (i = 0; stats_list[i].name; i++) \
+ buff[i] += snmp_get_cpu_field( \
+ mib_statistic, \
+ c, stats_list[i].entry); \
+ } \
+}
+
void inet_get_local_port_range(struct net *net, int *low, int *high);
#ifdef CONFIG_SYSCTL
--
2.5.5
[PATCH v4 2/7] proc: Reduce cache miss in snmp_seq_show
This is to use the generic interface snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Then snmp_seq_show is split into 2 parts to avoid build warning "the frame
size" larger than 1024.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv4/proc.c | 68 ++---
1 file changed, 46 insertions(+), 22 deletions(-)
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 9f665b6..cb04589 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -46,6 +46,8 @@
#include
#include
+#define TCPUDP_MIB_MAX max_t(u32, UDP_MIB_MAX, TCP_MIB_MAX)
+
/*
* Report socket allocation statistics [m...@utu.fi]
*/
@@ -378,13 +380,15 @@ static void icmp_put(struct seq_file *seq)
/*
* Called from the PROCfs module. This outputs /proc/net/snmp.
*/
-static int snmp_seq_show(struct seq_file *seq, void *v)
+static int snmp_seq_show_ipstats(struct seq_file *seq, void *v)
{
int i;
+ u64 buff64[IPSTATS_MIB_MAX];
struct net *net = seq->private;
- seq_puts(seq, "Ip: Forwarding DefaultTTL");
+ memset(buff64, 0, IPSTATS_MIB_MAX * sizeof(u64));
+ seq_puts(seq, "Ip: Forwarding DefaultTTL");
for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_ipstats_list[i].name);
@@ -393,57 +397,77 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
net->ipv4.sysctl_ip_default_ttl);
BUILD_BUG_ON(offsetof(struct ipstats_mib, mibs) != 0);
+ snmp_get_cpu_field64_batch(buff64, snmp4_ipstats_list,
+ net->mib.ip_statistics,
+ offsetof(struct ipstats_mib, syncp));
for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
- seq_printf(seq, " %llu",
- snmp_fold_field64(net->mib.ip_statistics,
-snmp4_ipstats_list[i].entry,
-offsetof(struct ipstats_mib,
syncp)));
+ seq_printf(seq, " %llu", buff64[i]);
- icmp_put(seq); /* RFC 2011 compatibility */
- icmpmsg_put(seq);
+ return 0;
+}
+
+static int snmp_seq_show_tcp_udp(struct seq_file *seq, void *v)
+{
+ int i;
+ unsigned long buff[TCPUDP_MIB_MAX];
+ struct net *net = seq->private;
+
+ memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
seq_puts(seq, "\nTcp:");
for (i = 0; snmp4_tcp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_tcp_list[i].name);
seq_puts(seq, "\nTcp:");
+ snmp_get_cpu_field_batch(buff, snmp4_tcp_list,
+net->mib.tcp_statistics);
for (i = 0; snmp4_tcp_list[i].name != NULL; i++) {
/* MaxConn field is signed, RFC 2012 */
if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN)
- seq_printf(seq, " %ld",
- snmp_fold_field(net->mib.tcp_statistics,
- snmp4_tcp_list[i].entry));
+ seq_printf(seq, " %ld", buff[i]);
else
- seq_printf(seq, " %lu",
- snmp_fold_field(net->mib.tcp_statistics,
- snmp4_tcp_list[i].entry));
+ seq_printf(seq, " %lu", buff[i]);
}
+ memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
+
+ snmp_get_cpu_field_batch(buff, snmp4_udp_list,
+net->mib.udp_statistics);
seq_puts(seq, "\nUdp:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
-
seq_puts(seq, "\nUdp:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
- seq_printf(seq, " %lu",
- snmp_fold_field(net->mib.udp_statistics,
- snmp4_udp_list[i].entry));
+ seq_printf(seq, " %lu", buff[i]);
+
+ memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
/* the UDP and UDP-Lite MIBs are the same */
seq_puts(seq, "\nUdpLite:");
+ snmp_get_cpu_field_batch(buff, snmp4_udp_list,
+net->mib.udplite_statistics);
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
-
seq_puts(seq, "\nUdpLite:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
- seq_printf(seq, " %lu",
-
[RFC PATCH v3 0/7] Reduce cache miss for snmp_fold_field
In a PowerPc server with large cpu number(160), besides commit
a3a773726c9f ("net: Optimize snmp stat aggregation by walking all
the percpu data at once"), I watched several other snmp_fold_field
callsites which will cause high cache miss rate.
My simple test case, which read from the procfs items endlessly:
/***/
#include
#include
#include
#include
#include
#define LINELEN 2560
int main(int argc, char **argv)
{
int i;
int fd = -1 ;
int rdsize = 0;
char buf[LINELEN+1];
buf[LINELEN] = 0;
memset(buf,0,LINELEN);
if(1 >= argc) {
printf("file name empty\n");
return -1;
}
fd = open(argv[1], O_RDWR, 0644);
if(0 > fd){
printf("open error\n");
return -2;
}
for(i=0;i<0x;i++) {
while(0 < (rdsize = read(fd,buf,LINELEN))){
//nothing here
}
lseek(fd, 0, SEEK_SET);
}
close(fd);
return 0;
}
/**/
compile and run:
gcc test.c -o test
perf stat -d -e cache-misses ./test /proc/net/snmp
perf stat -d -e cache-misses ./test /proc/net/snmp6
perf stat -d -e cache-misses ./test /proc/net/netstat
perf stat -d -e cache-misses ./test /proc/net/sctp/snmp
perf stat -d -e cache-misses ./test /proc/net/xfrm_stat
before the patch set:
Performance counter stats for 'system wide':
355911097 cache-misses
[40.08%]
2356829300 L1-dcache-loads
[60.04%]
355642645 L1-dcache-load-misses # 15.09% of all L1-dcache
hits [60.02%]
346544541 LLC-loads
[59.97%]
389763 LLC-load-misses #0.11% of all LL-cache
hits[40.02%]
6.245162638 seconds time elapsed
After the patch set:
===
Performance counter stats for 'system wide':
194992476 cache-misses
[40.03%]
6718051877 L1-dcache-loads
[60.07%]
194871921 L1-dcache-load-misses #2.90% of all L1-dcache
hits [60.11%]
187632232 LLC-loads
[60.04%]
464466 LLC-load-misses #0.25% of all LL-cache
hits[39.89%]
6.868422769 seconds time elapsed
The cache-miss rate can be reduced from 15% to 2.9%
v3:
- introduce generic interface (suggested by Marcelo Ricardo Leitner)
- use max_t instead of self defined macro (suggested by David Miller)
v2:
- fix bug in udplite statistics.
- snmp_seq_show is split into 2 parts
Jia He (7):
net:snmp: Introduce generic interfaces for snmp_get_cpu_field{,64}
proc: Reduce cache miss in {snmp,netstat}_seq_show
proc: Reduce cache miss in snmp6_seq_show
proc: Reduce cache miss in sctp_snmp_seq_show
proc: Reduce cache miss in xfrm_statistics_seq_show
ipv6: Remove useless parameter in __snmp6_fill_statsdev
net: Suppress the "Comparison to NULL could be written" warning
include/net/ip.h | 23 +
net/ipv4/proc.c | 138 +--
net/ipv6/addrconf.c | 12 ++---
net/ipv6/proc.c | 32
net/sctp/proc.c | 10 ++--
net/xfrm/xfrm_proc.c | 10 +++-
6 files changed, 157 insertions(+), 68 deletions(-)
--
1.8.3.1
[RFC PATCH v3 7/7] net: Suppress the "Comparison to NULL could be written" warning
This is to suppress the checkpatch.pl warning "Comparison to NULL
could be written". No functional changes here.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv4/proc.c | 32
net/sctp/proc.c | 2 +-
2 files changed, 17 insertions(+), 17 deletions(-)
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index c6fc80e..c6ee8a2 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -357,22 +357,22 @@ static void icmp_put(struct seq_file *seq)
atomic_long_t *ptr = net->mib.icmpmsg_statistics->mibs;
seq_puts(seq, "\nIcmp: InMsgs InErrors InCsumErrors");
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " In%s", icmpmibmap[i].name);
seq_puts(seq, " OutMsgs OutErrors");
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " Out%s", icmpmibmap[i].name);
seq_printf(seq, "\nIcmp: %lu %lu %lu",
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INMSGS),
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INERRORS),
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_CSUMERRORS));
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " %lu",
atomic_long_read(ptr + icmpmibmap[i].index));
seq_printf(seq, " %lu %lu",
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTMSGS),
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTERRORS));
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " %lu",
atomic_long_read(ptr + (icmpmibmap[i].index |
0x100)));
}
@@ -389,7 +389,7 @@ static int snmp_seq_show_ipstats(struct seq_file *seq, void
*v)
memset(buff64, 0, IPSTATS_MIB_MAX * sizeof(u64));
seq_puts(seq, "Ip: Forwarding DefaultTTL");
- for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
+ for (i = 0; snmp4_ipstats_list[i].name; i++)
seq_printf(seq, " %s", snmp4_ipstats_list[i].name);
seq_printf(seq, "\nIp: %d %d",
@@ -400,7 +400,7 @@ static int snmp_seq_show_ipstats(struct seq_file *seq, void
*v)
snmp_get_cpu_field64_batch(buff64, snmp4_ipstats_list,
net->mib.ip_statistics,
offsetof(struct ipstats_mib, syncp));
- for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
+ for (i = 0; snmp4_ipstats_list[i].name; i++)
seq_printf(seq, " %llu", buff64[i]);
return 0;
@@ -415,13 +415,13 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq,
void *v)
memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
seq_puts(seq, "\nTcp:");
- for (i = 0; snmp4_tcp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_tcp_list[i].name; i++)
seq_printf(seq, " %s", snmp4_tcp_list[i].name);
seq_puts(seq, "\nTcp:");
snmp_get_cpu_field_batch(buff, snmp4_tcp_list,
net->mib.tcp_statistics);
- for (i = 0; snmp4_tcp_list[i].name != NULL; i++) {
+ for (i = 0; snmp4_tcp_list[i].name; i++) {
/* MaxConn field is signed, RFC 2012 */
if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN)
seq_printf(seq, " %ld", buff[i]);
@@ -434,10 +434,10 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq,
void *v)
snmp_get_cpu_field_batch(buff, snmp4_udp_list,
net->mib.udp_statistics);
seq_puts(seq, "\nUdp:");
- for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_udp_list[i].name; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
seq_puts(seq, "\nUdp:");
- for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_udp_list[i].name; i++)
seq_printf(seq, " %lu", buff[i]);
memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
@@ -446,10 +446,10 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq,
void *v)
seq_puts(seq, "\nUdpLite:");
snmp_get_cpu_field_batch(buff, snmp4_udp_list,
net->mib.udplite_statistics);
- for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_udp_list[i].name; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
seq_puts(seq, "\nUdpLite:");
- for (i = 0; snmp4_udp_list[i].nam
[RFC PATCH v3 3/7] proc: Reduce cache miss in snmp6_seq_show
This is to use the generic interface snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv6/proc.c | 32 +++-
1 file changed, 23 insertions(+), 9 deletions(-)
diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c
index 679253d0..50ba2c3 100644
--- a/net/ipv6/proc.c
+++ b/net/ipv6/proc.c
@@ -30,6 +30,11 @@
#include
#include
+#define MAX4(a, b, c, d) \
+ max_t(u32, max_t(u32, a, b), max_t(u32, c, d))
+#define SNMP_MIB_MAX MAX4(UDP_MIB_MAX, TCP_MIB_MAX, \
+ IPSTATS_MIB_MAX, ICMP_MIB_MAX)
+
static int sockstat6_seq_show(struct seq_file *seq, void *v)
{
struct net *net = seq->private;
@@ -192,13 +197,19 @@ static void snmp6_seq_show_item(struct seq_file *seq,
void __percpu *pcpumib,
const struct snmp_mib *itemlist)
{
int i;
- unsigned long val;
-
- for (i = 0; itemlist[i].name; i++) {
- val = pcpumib ?
- snmp_fold_field(pcpumib, itemlist[i].entry) :
- atomic_long_read(smib + itemlist[i].entry);
- seq_printf(seq, "%-32s\t%lu\n", itemlist[i].name, val);
+ unsigned long buff[SNMP_MIB_MAX];
+
+ memset(buff, 0, sizeof(unsigned long) * SNMP_MIB_MAX);
+
+ if (pcpumib) {
+ snmp_get_cpu_field_batch(buff, itemlist, pcpumib);
+ for (i = 0; itemlist[i].name; i++)
+ seq_printf(seq, "%-32s\t%lu\n",
+ itemlist[i].name, buff[i]);
+ } else {
+ for (i = 0; itemlist[i].name; i++)
+ seq_printf(seq, "%-32s\t%lu\n", itemlist[i].name,
+ atomic_long_read(smib + itemlist[i].entry));
}
}
@@ -206,10 +217,13 @@ static void snmp6_seq_show_item64(struct seq_file *seq,
void __percpu *mib,
const struct snmp_mib *itemlist, size_t
syncpoff)
{
int i;
+ u64 buff64[SNMP_MIB_MAX];
+
+ memset(buff64, 0, sizeof(unsigned long) * SNMP_MIB_MAX);
+ snmp_get_cpu_field64_batch(buff64, itemlist, mib, syncpoff);
for (i = 0; itemlist[i].name; i++)
- seq_printf(seq, "%-32s\t%llu\n", itemlist[i].name,
- snmp_fold_field64(mib, itemlist[i].entry, syncpoff));
+ seq_printf(seq, "%-32s\t%llu\n", itemlist[i].name, buff64[i]);
}
static int snmp6_seq_show(struct seq_file *seq, void *v)
--
1.8.3.1
[RFC PATCH v3 6/7] ipv6: Remove useless parameter in __snmp6_fill_statsdev
The parameter items(always ICMP6_MIB_MAX) is useless for __snmp6_fill_statsdev.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv6/addrconf.c | 12 ++--
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index f418d2e..e170554 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4952,18 +4952,18 @@ static inline size_t inet6_if_nlmsg_size(void)
}
static inline void __snmp6_fill_statsdev(u64 *stats, atomic_long_t *mib,
- int items, int bytes)
+ int bytes)
{
int i;
- int pad = bytes - sizeof(u64) * items;
+ int pad = bytes - sizeof(u64) * ICMP6_MIB_MAX;
BUG_ON(pad < 0);
/* Use put_unaligned() because stats may not be aligned for u64. */
- put_unaligned(items, [0]);
- for (i = 1; i < items; i++)
+ put_unaligned(ICMP6_MIB_MAX, [0]);
+ for (i = 1; i < ICMP6_MIB_MAX; i++)
put_unaligned(atomic_long_read([i]), [i]);
- memset([items], 0, pad);
+ memset([ICMP6_MIB_MAX], 0, pad);
}
static inline void __snmp6_fill_stats64(u64 *stats, void __percpu *mib,
@@ -4996,7 +4996,7 @@ static void snmp6_fill_stats(u64 *stats, struct inet6_dev
*idev, int attrtype,
offsetof(struct ipstats_mib, syncp));
break;
case IFLA_INET6_ICMP6STATS:
- __snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs,
ICMP6_MIB_MAX, bytes);
+ __snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs,
bytes);
break;
}
}
--
1.8.3.1
[RFC PATCH v3 2/7] proc: Reduce cache miss in {snmp,netstat}_seq_show
This is to use the generic interface snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Then snmp_seq_show and netstat_seq_show are split into 2 parts to avoid build
warning "the frame size" larger than 1024 on s390.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv4/proc.c | 106 +++-
1 file changed, 74 insertions(+), 32 deletions(-)
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 9f665b6..c6fc80e 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -46,6 +46,8 @@
#include
#include
+#define TCPUDP_MIB_MAX max_t(u32, UDP_MIB_MAX, TCP_MIB_MAX)
+
/*
* Report socket allocation statistics [m...@utu.fi]
*/
@@ -378,13 +380,15 @@ static void icmp_put(struct seq_file *seq)
/*
* Called from the PROCfs module. This outputs /proc/net/snmp.
*/
-static int snmp_seq_show(struct seq_file *seq, void *v)
+static int snmp_seq_show_ipstats(struct seq_file *seq, void *v)
{
int i;
+ u64 buff64[IPSTATS_MIB_MAX];
struct net *net = seq->private;
- seq_puts(seq, "Ip: Forwarding DefaultTTL");
+ memset(buff64, 0, IPSTATS_MIB_MAX * sizeof(u64));
+ seq_puts(seq, "Ip: Forwarding DefaultTTL");
for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_ipstats_list[i].name);
@@ -393,57 +397,77 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
net->ipv4.sysctl_ip_default_ttl);
BUILD_BUG_ON(offsetof(struct ipstats_mib, mibs) != 0);
+ snmp_get_cpu_field64_batch(buff64, snmp4_ipstats_list,
+ net->mib.ip_statistics,
+ offsetof(struct ipstats_mib, syncp));
for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
- seq_printf(seq, " %llu",
- snmp_fold_field64(net->mib.ip_statistics,
-snmp4_ipstats_list[i].entry,
-offsetof(struct ipstats_mib,
syncp)));
+ seq_printf(seq, " %llu", buff64[i]);
- icmp_put(seq); /* RFC 2011 compatibility */
- icmpmsg_put(seq);
+ return 0;
+}
+
+static int snmp_seq_show_tcp_udp(struct seq_file *seq, void *v)
+{
+ int i;
+ unsigned long buff[TCPUDP_MIB_MAX];
+ struct net *net = seq->private;
+
+ memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
seq_puts(seq, "\nTcp:");
for (i = 0; snmp4_tcp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_tcp_list[i].name);
seq_puts(seq, "\nTcp:");
+ snmp_get_cpu_field_batch(buff, snmp4_tcp_list,
+net->mib.tcp_statistics);
for (i = 0; snmp4_tcp_list[i].name != NULL; i++) {
/* MaxConn field is signed, RFC 2012 */
if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN)
- seq_printf(seq, " %ld",
- snmp_fold_field(net->mib.tcp_statistics,
- snmp4_tcp_list[i].entry));
+ seq_printf(seq, " %ld", buff[i]);
else
- seq_printf(seq, " %lu",
- snmp_fold_field(net->mib.tcp_statistics,
- snmp4_tcp_list[i].entry));
+ seq_printf(seq, " %lu", buff[i]);
}
+ memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
+
+ snmp_get_cpu_field_batch(buff, snmp4_udp_list,
+net->mib.udp_statistics);
seq_puts(seq, "\nUdp:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
-
seq_puts(seq, "\nUdp:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
- seq_printf(seq, " %lu",
- snmp_fold_field(net->mib.udp_statistics,
- snmp4_udp_list[i].entry));
+ seq_printf(seq, " %lu", buff[i]);
+
+ memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
/* the UDP and UDP-Lite MIBs are the same */
seq_puts(seq, "\nUdpLite:");
+ snmp_get_cpu_field_batch(buff, snmp4_udp_list,
+net->mib.udplite_statistics);
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
-
seq_puts(seq, "\nUdpLite:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
- seq_printf(seq, " %lu&q
[RFC PATCH v3 5/7] proc: Reduce cache miss in xfrm_statistics_seq_show
This is to use the generic interface snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/xfrm/xfrm_proc.c | 10 --
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/net/xfrm/xfrm_proc.c b/net/xfrm/xfrm_proc.c
index 9c4fbd8..2b280fc 100644
--- a/net/xfrm/xfrm_proc.c
+++ b/net/xfrm/xfrm_proc.c
@@ -52,10 +52,16 @@ static int xfrm_statistics_seq_show(struct seq_file *seq,
void *v)
{
struct net *net = seq->private;
int i;
+ unsigned long buff[LINUX_MIB_XFRMMAX];
+
+ memset(buff, 0, sizeof(unsigned long) * LINUX_MIB_XFRMMAX);
+
+ snmp_get_cpu_field_batch(buff, xfrm_mib_list,
+net->mib.xfrm_statistics);
for (i = 0; xfrm_mib_list[i].name; i++)
seq_printf(seq, "%-24s\t%lu\n", xfrm_mib_list[i].name,
- snmp_fold_field(net->mib.xfrm_statistics,
- xfrm_mib_list[i].entry));
+ buff[i]);
+
return 0;
}
--
1.8.3.1
[RFC PATCH v3 4/7] proc: Reduce cache miss in sctp_snmp_seq_show
This is to use the generic interface snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/sctp/proc.c | 8 ++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/net/sctp/proc.c b/net/sctp/proc.c
index ef8ba77..0487c01 100644
--- a/net/sctp/proc.c
+++ b/net/sctp/proc.c
@@ -75,11 +75,15 @@ static int sctp_snmp_seq_show(struct seq_file *seq, void *v)
{
struct net *net = seq->private;
int i;
+ unsigned long buff[SCTP_MIB_MAX];
+ memset(buff, 0, sizeof(unsigned long) * SCTP_MIB_MAX);
+
+ snmp_get_cpu_field_batch(buff, sctp_snmp_list,
+net->sctp.sctp_statistics);
for (i = 0; sctp_snmp_list[i].name != NULL; i++)
seq_printf(seq, "%-32s\t%ld\n", sctp_snmp_list[i].name,
- snmp_fold_field(net->sctp.sctp_statistics,
- sctp_snmp_list[i].entry));
+ buff[i]);
return 0;
}
--
1.8.3.1
[RFC PATCH v3 1/7] net:snmp: Introduce generic batch interfaces for snmp_get_cpu_field{,64}
This is to introduced the generic batch interfaces for snmp_get_cpu_field{,64}.
It exchanges the two for-loops for collecting the percpu statistics data.
This can aggregate the data by going through all the items of each cpu
sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
Suggested-by: Marcelo Ricardo Leitner <marcelo.leit...@gmail.com>
---
include/net/ip.h | 23 +++
1 file changed, 23 insertions(+)
diff --git a/include/net/ip.h b/include/net/ip.h
index 9742b92..bc43c0f 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -219,6 +219,29 @@ static inline u64 snmp_fold_field64(void __percpu *mib,
int offt, size_t syncp_o
}
#endif
+#define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
+{ \
+ int i, c; \
+ for_each_possible_cpu(c) { \
+ for (i = 0; stats_list[i].name; i++) \
+ buff64[i] += snmp_get_cpu_field64( \
+ mib_statistic, \
+ c, stats_list[i].entry, \
+ offset); \
+ } \
+}
+
+#define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
+{ \
+ int i, c; \
+ for_each_possible_cpu(c) { \
+ for (i = 0; stats_list[i].name; i++) \
+ buff[i] += snmp_get_cpu_field( \
+ mib_statistic, \
+ c, stats_list[i].entry); \
+ } \
+}
+
void inet_get_local_port_range(struct net *net, int *low, int *high);
#ifdef CONFIG_SYSCTL
--
1.8.3.1
[RFC PATCH v2 6/6] net: Suppress the "Comparison to NULL could be written" warning
This is to suppress the checkpatch.pl warning "Comparison to NULL
could be written". No functional changes here.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv4/proc.c | 44 ++--
net/sctp/proc.c | 4 ++--
net/xfrm/xfrm_proc.c | 4 ++--
3 files changed, 26 insertions(+), 26 deletions(-)
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index f413fdc..bf0bb22 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -358,22 +358,22 @@ static void icmp_put(struct seq_file *seq)
atomic_long_t *ptr = net->mib.icmpmsg_statistics->mibs;
seq_puts(seq, "\nIcmp: InMsgs InErrors InCsumErrors");
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " In%s", icmpmibmap[i].name);
seq_puts(seq, " OutMsgs OutErrors");
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " Out%s", icmpmibmap[i].name);
seq_printf(seq, "\nIcmp: %lu %lu %lu",
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INMSGS),
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INERRORS),
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_CSUMERRORS));
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " %lu",
atomic_long_read(ptr + icmpmibmap[i].index));
seq_printf(seq, " %lu %lu",
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTMSGS),
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTERRORS));
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " %lu",
atomic_long_read(ptr + (icmpmibmap[i].index |
0x100)));
}
@@ -390,7 +390,7 @@ static int snmp_seq_show_ipstats(struct seq_file *seq, void
*v)
memset(buff64, 0, IPSTATS_MIB_MAX * sizeof(u64));
seq_puts(seq, "Ip: Forwarding DefaultTTL");
- for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
+ for (i = 0; snmp4_ipstats_list[i].name; i++)
seq_printf(seq, " %s", snmp4_ipstats_list[i].name);
seq_printf(seq, "\nIp: %d %d",
@@ -400,13 +400,13 @@ static int snmp_seq_show_ipstats(struct seq_file *seq,
void *v)
BUILD_BUG_ON(offsetof(struct ipstats_mib, mibs) != 0);
for_each_possible_cpu(c) {
- for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
+ for (i = 0; snmp4_ipstats_list[i].name; i++)
buff64[i] += snmp_get_cpu_field64(
net->mib.ip_statistics,
c, snmp4_ipstats_list[i].entry,
offsetof(struct ipstats_mib, syncp));
}
- for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
+ for (i = 0; snmp4_ipstats_list[i].name; i++)
seq_printf(seq, " %llu", buff64[i]);
return 0;
@@ -421,17 +421,17 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq,
void *v)
memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
seq_puts(seq, "\nTcp:");
- for (i = 0; snmp4_tcp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_tcp_list[i].name; i++)
seq_printf(seq, " %s", snmp4_tcp_list[i].name);
seq_puts(seq, "\nTcp:");
for_each_possible_cpu(c) {
- for (i = 0; snmp4_tcp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_tcp_list[i].name; i++)
buff[i] += snmp_get_cpu_field(net->mib.tcp_statistics,
c, snmp4_tcp_list[i].entry);
}
- for (i = 0; snmp4_tcp_list[i].name != NULL; i++) {
+ for (i = 0; snmp4_tcp_list[i].name; i++) {
/* MaxConn field is signed, RFC 2012 */
if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN)
seq_printf(seq, " %ld", buff[i]);
@@ -442,15 +442,15 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq,
void *v)
memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
for_each_possible_cpu(c) {
- for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_udp_list[i].name; i++)
buff[i] += snmp_get_cpu_field(net->mib.udp_statistics,
c, snmp4_udp_list[i].entry);
}
seq_puts(seq, "\nUdp:");
- for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_udp_li
[RFC PATCH v2 3/6] proc: Reduce cache miss in sctp_snmp_seq_show
This patch exchanges the two loop for collecting the percpu
statistics data. This can reduce cache misses by going through
all the items of each cpu sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/sctp/proc.c | 13 ++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/net/sctp/proc.c b/net/sctp/proc.c
index ef8ba77..085fb95 100644
--- a/net/sctp/proc.c
+++ b/net/sctp/proc.c
@@ -74,12 +74,19 @@ static const struct snmp_mib sctp_snmp_list[] = {
static int sctp_snmp_seq_show(struct seq_file *seq, void *v)
{
struct net *net = seq->private;
- int i;
+ int i, c;
+ unsigned long buff[SCTP_MIB_MAX];
+ memset(buff, 0, sizeof(unsigned long) * SCTP_MIB_MAX);
+
+ for_each_possible_cpu(c)
+ for (i = 0; sctp_snmp_list[i].name != NULL; i++)
+ buff[i] += snmp_get_cpu_field(
+ net->sctp.sctp_statistics,
+ c, sctp_snmp_list[i].entry);
for (i = 0; sctp_snmp_list[i].name != NULL; i++)
seq_printf(seq, "%-32s\t%ld\n", sctp_snmp_list[i].name,
- snmp_fold_field(net->sctp.sctp_statistics,
- sctp_snmp_list[i].entry));
+ buff[i]);
return 0;
}
--
1.8.3.1
[RFC PATCH v2 1/6] proc: Reduce cache miss in {snmp,netstat}_seq_show
This patch exchanges the two loop for collecting the percpu statistics
data. This can aggregate the data by going through all the items of each
cpu sequentially. Then snmp_seq_show is split into 2 parts to avoid build
warning "the frame size" larger than 1024.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv4/proc.c | 112
1 file changed, 81 insertions(+), 31 deletions(-)
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 9f665b6..f413fdc 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -46,6 +46,9 @@
#include
#include
+#define MAX(a, b) ((u32)(a) >= (u32)(b) ? (a) : (b))
+#define TCPUDP_MIB_MAX MAX(UDP_MIB_MAX, TCP_MIB_MAX)
+
/*
* Report socket allocation statistics [m...@utu.fi]
*/
@@ -378,13 +381,15 @@ static void icmp_put(struct seq_file *seq)
/*
* Called from the PROCfs module. This outputs /proc/net/snmp.
*/
-static int snmp_seq_show(struct seq_file *seq, void *v)
+static int snmp_seq_show_ipstats(struct seq_file *seq, void *v)
{
- int i;
+ int i, c;
+ u64 buff64[IPSTATS_MIB_MAX];
struct net *net = seq->private;
- seq_puts(seq, "Ip: Forwarding DefaultTTL");
+ memset(buff64, 0, IPSTATS_MIB_MAX * sizeof(u64));
+ seq_puts(seq, "Ip: Forwarding DefaultTTL");
for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_ipstats_list[i].name);
@@ -393,57 +398,92 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
net->ipv4.sysctl_ip_default_ttl);
BUILD_BUG_ON(offsetof(struct ipstats_mib, mibs) != 0);
+
+ for_each_possible_cpu(c) {
+ for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
+ buff64[i] += snmp_get_cpu_field64(
+ net->mib.ip_statistics,
+ c, snmp4_ipstats_list[i].entry,
+ offsetof(struct ipstats_mib, syncp));
+ }
for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
- seq_printf(seq, " %llu",
- snmp_fold_field64(net->mib.ip_statistics,
-snmp4_ipstats_list[i].entry,
-offsetof(struct ipstats_mib,
syncp)));
+ seq_printf(seq, " %llu", buff64[i]);
- icmp_put(seq); /* RFC 2011 compatibility */
- icmpmsg_put(seq);
+ return 0;
+}
+
+static int snmp_seq_show_tcp_udp(struct seq_file *seq, void *v)
+{
+ int i, c;
+ unsigned long buff[TCPUDP_MIB_MAX];
+ struct net *net = seq->private;
+
+ memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
seq_puts(seq, "\nTcp:");
for (i = 0; snmp4_tcp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_tcp_list[i].name);
seq_puts(seq, "\nTcp:");
+ for_each_possible_cpu(c) {
+ for (i = 0; snmp4_tcp_list[i].name != NULL; i++)
+ buff[i] += snmp_get_cpu_field(net->mib.tcp_statistics,
+ c, snmp4_tcp_list[i].entry);
+ }
+
for (i = 0; snmp4_tcp_list[i].name != NULL; i++) {
/* MaxConn field is signed, RFC 2012 */
if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN)
- seq_printf(seq, " %ld",
- snmp_fold_field(net->mib.tcp_statistics,
- snmp4_tcp_list[i].entry));
+ seq_printf(seq, " %ld", buff[i]);
else
- seq_printf(seq, " %lu",
- snmp_fold_field(net->mib.tcp_statistics,
- snmp4_tcp_list[i].entry));
+ seq_printf(seq, " %lu", buff[i]);
}
+ memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
+
+ for_each_possible_cpu(c) {
+ for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+ buff[i] += snmp_get_cpu_field(net->mib.udp_statistics,
+ c, snmp4_udp_list[i].entry);
+ }
seq_puts(seq, "\nUdp:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
-
seq_puts(seq, "\nUdp:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
- seq_printf(seq, " %lu",
- snmp_fold_field(net->mib.udp_statistics,
- snmp4_udp_list[i].entry));
+ seq_printf(seq, " %lu", buff[i]);
+
+ memset(
[RFC PATCH v2 5/6] ipv6: Remove useless parameter in __snmp6_fill_statsdev
The parameter items(always ICMP6_MIB_MAX) is useless for __snmp6_fill_statsdev.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv6/addrconf.c | 12 ++--
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index f418d2e..e170554 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4952,18 +4952,18 @@ static inline size_t inet6_if_nlmsg_size(void)
}
static inline void __snmp6_fill_statsdev(u64 *stats, atomic_long_t *mib,
- int items, int bytes)
+ int bytes)
{
int i;
- int pad = bytes - sizeof(u64) * items;
+ int pad = bytes - sizeof(u64) * ICMP6_MIB_MAX;
BUG_ON(pad < 0);
/* Use put_unaligned() because stats may not be aligned for u64. */
- put_unaligned(items, [0]);
- for (i = 1; i < items; i++)
+ put_unaligned(ICMP6_MIB_MAX, [0]);
+ for (i = 1; i < ICMP6_MIB_MAX; i++)
put_unaligned(atomic_long_read([i]), [i]);
- memset([items], 0, pad);
+ memset([ICMP6_MIB_MAX], 0, pad);
}
static inline void __snmp6_fill_stats64(u64 *stats, void __percpu *mib,
@@ -4996,7 +4996,7 @@ static void snmp6_fill_stats(u64 *stats, struct inet6_dev
*idev, int attrtype,
offsetof(struct ipstats_mib, syncp));
break;
case IFLA_INET6_ICMP6STATS:
- __snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs,
ICMP6_MIB_MAX, bytes);
+ __snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs,
bytes);
break;
}
}
--
1.8.3.1
[RFC PATCH v2 4/6] proc: Reduce cache miss in xfrm_statistics_seq_show
This patch exchanges the two loop for collecting the percpu
statistics data. This can reduce cache misses by going through
all the items of each cpu sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/xfrm/xfrm_proc.c | 17 +
1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/net/xfrm/xfrm_proc.c b/net/xfrm/xfrm_proc.c
index 9c4fbd8..c9df546 100644
--- a/net/xfrm/xfrm_proc.c
+++ b/net/xfrm/xfrm_proc.c
@@ -51,11 +51,20 @@ static const struct snmp_mib xfrm_mib_list[] = {
static int xfrm_statistics_seq_show(struct seq_file *seq, void *v)
{
struct net *net = seq->private;
- int i;
- for (i = 0; xfrm_mib_list[i].name; i++)
+ int i, c;
+ unsigned long buff[LINUX_MIB_XFRMMAX];
+
+ memset(buff, 0, sizeof(unsigned long) * LINUX_MIB_XFRMMAX);
+
+ for_each_possible_cpu(c)
+ for (i = 0; xfrm_mib_list[i].name != NULL; i++)
+ buff[i] += snmp_get_cpu_field(
+ net->mib.xfrm_statistics,
+ c, xfrm_mib_list[i].entry);
+ for (i = 0; xfrm_mib_list[i].name != NULL; i++)
seq_printf(seq, "%-24s\t%lu\n", xfrm_mib_list[i].name,
- snmp_fold_field(net->mib.xfrm_statistics,
- xfrm_mib_list[i].entry));
+ buff[i]);
+
return 0;
}
--
1.8.3.1
[RFC PATCH v2 2/6] proc: Reduce cache miss in snmp6_seq_show
This patch exchanges the two loop for collecting the percpu
statistics data. This can reduce cache misses by going through
all the items of each cpu sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv6/proc.c | 47 ---
1 file changed, 36 insertions(+), 11 deletions(-)
diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c
index 679253d0..c834646 100644
--- a/net/ipv6/proc.c
+++ b/net/ipv6/proc.c
@@ -30,6 +30,13 @@
#include
#include
+#define MAX(a, b) ((u32)(a) >= (u32)(b) ? (a) : (b))
+
+#define MAX4(a, b, c, d) \
+ MAX(MAX(a, b), MAX(c, d))
+#define SNMP_MIB_MAX MAX4(UDP_MIB_MAX, TCP_MIB_MAX, \
+ IPSTATS_MIB_MAX, ICMP_MIB_MAX)
+
static int sockstat6_seq_show(struct seq_file *seq, void *v)
{
struct net *net = seq->private;
@@ -191,25 +198,43 @@ static void snmp6_seq_show_item(struct seq_file *seq,
void __percpu *pcpumib,
atomic_long_t *smib,
const struct snmp_mib *itemlist)
{
- int i;
- unsigned long val;
-
- for (i = 0; itemlist[i].name; i++) {
- val = pcpumib ?
- snmp_fold_field(pcpumib, itemlist[i].entry) :
- atomic_long_read(smib + itemlist[i].entry);
- seq_printf(seq, "%-32s\t%lu\n", itemlist[i].name, val);
+ int i, c;
+ unsigned long buff[SNMP_MIB_MAX];
+
+ memset(buff, 0, sizeof(unsigned long) * SNMP_MIB_MAX);
+
+ if (pcpumib) {
+ for_each_possible_cpu(c)
+ for (i = 0; itemlist[i].name; i++)
+ buff[i] += snmp_get_cpu_field(pcpumib, c,
+ itemlist[i].entry);
+ for (i = 0; itemlist[i].name; i++)
+ seq_printf(seq, "%-32s\t%lu\n",
+ itemlist[i].name, buff[i]);
+ } else {
+ for (i = 0; itemlist[i].name; i++)
+ seq_printf(seq, "%-32s\t%lu\n", itemlist[i].name,
+ atomic_long_read(smib + itemlist[i].entry));
}
}
static void snmp6_seq_show_item64(struct seq_file *seq, void __percpu *mib,
const struct snmp_mib *itemlist, size_t
syncpoff)
{
- int i;
+ int i, c;
+ u64 buff[SNMP_MIB_MAX];
+
+ memset(buff, 0, sizeof(unsigned long) * SNMP_MIB_MAX);
+ for_each_possible_cpu(c) {
+ for (i = 0; itemlist[i].name; i++) {
+ buff[i] += snmp_get_cpu_field64(mib, c,
+ itemlist[i].entry,
+ syncpoff);
+ }
+ }
for (i = 0; itemlist[i].name; i++)
- seq_printf(seq, "%-32s\t%llu\n", itemlist[i].name,
- snmp_fold_field64(mib, itemlist[i].entry, syncpoff));
+ seq_printf(seq, "%-32s\t%llu\n", itemlist[i].name, buff[i]);
}
static int snmp6_seq_show(struct seq_file *seq, void *v)
--
1.8.3.1
[RFC PATCH v2 0/6] Reduce cache miss for snmp_fold_field
In a PowerPc server with large cpu number(160), besides commit
a3a773726c9f ("net: Optimize snmp stat aggregation by walking all
the percpu data at once"), I watched several other snmp_fold_field
callsites which will cause high cache miss rate.
My simple test case, which read from the procfs items endlessly:
/***/
#include
#include
#include
#include
#include
#define LINELEN 2560
int main(int argc, char **argv)
{
int i;
int fd = -1 ;
int rdsize = 0;
char buf[LINELEN+1];
buf[LINELEN] = 0;
memset(buf,0,LINELEN);
if(1 >= argc) {
printf("file name empty\n");
return -1;
}
fd = open(argv[1], O_RDWR, 0644);
if(0 > fd){
printf("open error\n");
return -2;
}
for(i=0;i<0x;i++) {
while(0 < (rdsize = read(fd,buf,LINELEN))){
//nothing here
}
lseek(fd, 0, SEEK_SET);
}
close(fd);
return 0;
}
/**/
compile and run:
gcc test.c -o test
perf stat -d -e cache-misses ./test /proc/net/snmp
perf stat -d -e cache-misses ./test /proc/net/snmp6
perf stat -d -e cache-misses ./test /proc/net/netstat
perf stat -d -e cache-misses ./test /proc/net/sctp/snmp
perf stat -d -e cache-misses ./test /proc/net/xfrm_stat
before the patch set:
Performance counter stats for 'system wide':
355911097 cache-misses
[40.08%]
2356829300 L1-dcache-loads
[60.04%]
355642645 L1-dcache-load-misses # 15.09% of all L1-dcache
hits [60.02%]
346544541 LLC-loads
[59.97%]
389763 LLC-load-misses #0.11% of all LL-cache
hits[40.02%]
6.245162638 seconds time elapsed
After the patch set:
===
Performance counter stats for 'system wide':
194992476 cache-misses
[40.03%]
6718051877 L1-dcache-loads
[60.07%]
194871921 L1-dcache-load-misses #2.90% of all L1-dcache
hits [60.11%]
187632232 LLC-loads
[60.04%]
464466 LLC-load-misses #0.25% of all LL-cache
hits[39.89%]
6.868422769 seconds time elapsed
The cache-miss rate can be reduced from 15% to 2.9%
v2:
- 1/6 fix bug in udplite statistics.
- 1/6 snmp_seq_show is split into 2 parts
Jia He (6):
proc: Reduce cache miss in {snmp,netstat}_seq_show
proc: Reduce cache miss in snmp6_seq_show
proc: Reduce cache miss in sctp_snmp_seq_show
proc: Reduce cache miss in xfrm_statistics_seq_show
ipv6: Remove useless parameter in __snmp6_fill_statsdev
net: Suppress the "Comparison to NULL could be written" warning
net/ipv4/proc.c | 144 ++-
net/ipv6/addrconf.c | 12 ++---
net/ipv6/proc.c | 47 +
net/sctp/proc.c | 15 --
net/xfrm/xfrm_proc.c | 15 --
5 files changed, 162 insertions(+), 71 deletions(-)
--
1.8.3.1
[RFC PATCH 5/6] ipv6: Remove useless parameter in __snmp6_fill_statsdev
The parameter items(always ICMP6_MIB_MAX) is useless for __snmp6_fill_statsdev.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv6/addrconf.c | 12 ++--
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index df8425f..0fa5aa1 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4944,18 +4944,18 @@ static inline size_t inet6_if_nlmsg_size(void)
}
static inline void __snmp6_fill_statsdev(u64 *stats, atomic_long_t *mib,
- int items, int bytes)
+ int bytes)
{
int i;
- int pad = bytes - sizeof(u64) * items;
+ int pad = bytes - sizeof(u64) * ICMP6_MIB_MAX;
BUG_ON(pad < 0);
/* Use put_unaligned() because stats may not be aligned for u64. */
- put_unaligned(items, [0]);
- for (i = 1; i < items; i++)
+ put_unaligned(ICMP6_MIB_MAX, [0]);
+ for (i = 1; i < ICMP6_MIB_MAX; i++)
put_unaligned(atomic_long_read([i]), [i]);
- memset([items], 0, pad);
+ memset([ICMP6_MIB_MAX], 0, pad);
}
static inline void __snmp6_fill_stats64(u64 *stats, void __percpu *mib,
@@ -4988,7 +4988,7 @@ static void snmp6_fill_stats(u64 *stats, struct inet6_dev
*idev, int attrtype,
offsetof(struct ipstats_mib, syncp));
break;
case IFLA_INET6_ICMP6STATS:
- __snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs,
ICMP6_MIB_MAX, bytes);
+ __snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs,
bytes);
break;
}
}
--
1.8.3.1
[RFC PATCH 2/6] proc: Reduce cache miss in snmp6_seq_show
This patch exchanges the two loop for collecting the percpu
statistics data. This can reduce cache misses by going through
all the items of each cpu sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv6/proc.c | 47 ---
1 file changed, 36 insertions(+), 11 deletions(-)
diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c
index 679253d0..c834646 100644
--- a/net/ipv6/proc.c
+++ b/net/ipv6/proc.c
@@ -30,6 +30,13 @@
#include
#include
+#define MAX(a, b) ((u32)(a) >= (u32)(b) ? (a) : (b))
+
+#define MAX4(a, b, c, d) \
+ MAX(MAX(a, b), MAX(c, d))
+#define SNMP_MIB_MAX MAX4(UDP_MIB_MAX, TCP_MIB_MAX, \
+ IPSTATS_MIB_MAX, ICMP_MIB_MAX)
+
static int sockstat6_seq_show(struct seq_file *seq, void *v)
{
struct net *net = seq->private;
@@ -191,25 +198,43 @@ static void snmp6_seq_show_item(struct seq_file *seq,
void __percpu *pcpumib,
atomic_long_t *smib,
const struct snmp_mib *itemlist)
{
- int i;
- unsigned long val;
-
- for (i = 0; itemlist[i].name; i++) {
- val = pcpumib ?
- snmp_fold_field(pcpumib, itemlist[i].entry) :
- atomic_long_read(smib + itemlist[i].entry);
- seq_printf(seq, "%-32s\t%lu\n", itemlist[i].name, val);
+ int i, c;
+ unsigned long buff[SNMP_MIB_MAX];
+
+ memset(buff, 0, sizeof(unsigned long) * SNMP_MIB_MAX);
+
+ if (pcpumib) {
+ for_each_possible_cpu(c)
+ for (i = 0; itemlist[i].name; i++)
+ buff[i] += snmp_get_cpu_field(pcpumib, c,
+ itemlist[i].entry);
+ for (i = 0; itemlist[i].name; i++)
+ seq_printf(seq, "%-32s\t%lu\n",
+ itemlist[i].name, buff[i]);
+ } else {
+ for (i = 0; itemlist[i].name; i++)
+ seq_printf(seq, "%-32s\t%lu\n", itemlist[i].name,
+ atomic_long_read(smib + itemlist[i].entry));
}
}
static void snmp6_seq_show_item64(struct seq_file *seq, void __percpu *mib,
const struct snmp_mib *itemlist, size_t
syncpoff)
{
- int i;
+ int i, c;
+ u64 buff[SNMP_MIB_MAX];
+
+ memset(buff, 0, sizeof(unsigned long) * SNMP_MIB_MAX);
+ for_each_possible_cpu(c) {
+ for (i = 0; itemlist[i].name; i++) {
+ buff[i] += snmp_get_cpu_field64(mib, c,
+ itemlist[i].entry,
+ syncpoff);
+ }
+ }
for (i = 0; itemlist[i].name; i++)
- seq_printf(seq, "%-32s\t%llu\n", itemlist[i].name,
- snmp_fold_field64(mib, itemlist[i].entry, syncpoff));
+ seq_printf(seq, "%-32s\t%llu\n", itemlist[i].name, buff[i]);
}
static int snmp6_seq_show(struct seq_file *seq, void *v)
--
1.8.3.1
[RFC PATCH 1/6] proc: Reduce cache miss in {snmp,netstat}_seq_show
This patch exchanges the two loop for collecting the percpu statistics
data. This can aggregate the data by going through all the items of each
cpu sequentially. In snmp_seq_show, just use one buff copy to dislay the
Udp and UdpLite data because they are the same.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv4/proc.c | 78 -
1 file changed, 50 insertions(+), 28 deletions(-)
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 9f665b6..ed09566 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -380,11 +380,15 @@ static void icmp_put(struct seq_file *seq)
*/
static int snmp_seq_show(struct seq_file *seq, void *v)
{
- int i;
+ int i, c;
+ unsigned long buff[TCP_MIB_MAX];
+ u64 buff64[IPSTATS_MIB_MAX];
struct net *net = seq->private;
- seq_puts(seq, "Ip: Forwarding DefaultTTL");
+ memset(buff, 0, TCP_MIB_MAX * sizeof(unsigned long));
+ memset(buff64, 0, IPSTATS_MIB_MAX * sizeof(u64));
+ seq_puts(seq, "Ip: Forwarding DefaultTTL");
for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_ipstats_list[i].name);
@@ -393,11 +397,16 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
net->ipv4.sysctl_ip_default_ttl);
BUILD_BUG_ON(offsetof(struct ipstats_mib, mibs) != 0);
+
+ for_each_possible_cpu(c) {
+ for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
+ buff64[i] += snmp_get_cpu_field64(
+ net->mib.ip_statistics,
+ c, snmp4_ipstats_list[i].entry,
+ offsetof(struct ipstats_mib, syncp));
+ }
for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
- seq_printf(seq, " %llu",
- snmp_fold_field64(net->mib.ip_statistics,
-snmp4_ipstats_list[i].entry,
-offsetof(struct ipstats_mib,
syncp)));
+ seq_printf(seq, " %llu", buff64[i]);
icmp_put(seq); /* RFC 2011 compatibility */
icmpmsg_put(seq);
@@ -407,38 +416,41 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
seq_printf(seq, " %s", snmp4_tcp_list[i].name);
seq_puts(seq, "\nTcp:");
+ for_each_possible_cpu(c) {
+ for (i = 0; snmp4_tcp_list[i].name != NULL; i++)
+ buff[i] += snmp_get_cpu_field(net->mib.tcp_statistics,
+ c, snmp4_tcp_list[i].entry);
+ }
+
for (i = 0; snmp4_tcp_list[i].name != NULL; i++) {
/* MaxConn field is signed, RFC 2012 */
if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN)
- seq_printf(seq, " %ld",
- snmp_fold_field(net->mib.tcp_statistics,
- snmp4_tcp_list[i].entry));
+ seq_printf(seq, " %ld", buff[i]);
else
- seq_printf(seq, " %lu",
- snmp_fold_field(net->mib.tcp_statistics,
- snmp4_tcp_list[i].entry));
+ seq_printf(seq, " %lu", buff[i]);
}
+ memset(buff, 0, TCP_MIB_MAX * sizeof(unsigned long));
+
+ for_each_possible_cpu(c) {
+ for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+ buff[i] += snmp_get_cpu_field(net->mib.udp_statistics,
+ c, snmp4_udp_list[i].entry);
+ }
seq_puts(seq, "\nUdp:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
-
seq_puts(seq, "\nUdp:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
- seq_printf(seq, " %lu",
- snmp_fold_field(net->mib.udp_statistics,
- snmp4_udp_list[i].entry));
+ seq_printf(seq, " %lu", buff[i]);
/* the UDP and UDP-Lite MIBs are the same */
seq_puts(seq, "\nUdpLite:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
-
seq_puts(seq, "\nUdpLite:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
- seq_printf(seq, " %lu",
- snmp_fold_field(net->mib.udplite_statistics,
- snmp4_udp_list[i].entry));
+ seq_printf(seq, &qu
[RFC PATCH 3/6] proc: Reduce cache miss in sctp_snmp_seq_show
This patch exchanges the two loop for collecting the percpu
statistics data. This can reduce cache misses by going through
all the items of each cpu sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/sctp/proc.c | 13 ++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/net/sctp/proc.c b/net/sctp/proc.c
index ef8ba77..085fb95 100644
--- a/net/sctp/proc.c
+++ b/net/sctp/proc.c
@@ -74,12 +74,19 @@ static const struct snmp_mib sctp_snmp_list[] = {
static int sctp_snmp_seq_show(struct seq_file *seq, void *v)
{
struct net *net = seq->private;
- int i;
+ int i, c;
+ unsigned long buff[SCTP_MIB_MAX];
+ memset(buff, 0, sizeof(unsigned long) * SCTP_MIB_MAX);
+
+ for_each_possible_cpu(c)
+ for (i = 0; sctp_snmp_list[i].name != NULL; i++)
+ buff[i] += snmp_get_cpu_field(
+ net->sctp.sctp_statistics,
+ c, sctp_snmp_list[i].entry);
for (i = 0; sctp_snmp_list[i].name != NULL; i++)
seq_printf(seq, "%-32s\t%ld\n", sctp_snmp_list[i].name,
- snmp_fold_field(net->sctp.sctp_statistics,
- sctp_snmp_list[i].entry));
+ buff[i]);
return 0;
}
--
1.8.3.1
[RFC PATCH 0/6] Reduce cache miss for snmp_fold_field
In a PowerPc server with large cpu number(160), besides commit
a3a773726c9f ("net: Optimize snmp stat aggregation by walking all
the percpu data at once"), I watched several other snmp_fold_field
callsites which will cause high cache miss rate.
#My simple test case, which read from the procfs items endlessly:
/***/
#include
#include
#include
#include
#include
#define LINELEN 2560
int main(int argc, char **argv)
{
int i;
int fd = -1 ;
int rdsize = 0;
char buf[LINELEN+1];
buf[LINELEN] = 0;
memset(buf,0,LINELEN);
if(1 >= argc) {
printf("file name empty\n");
return -1;
}
fd = open(argv[1], O_RDWR, 0644);
if(0 > fd){
printf("open error\n");
return -2;
}
for(i=0;i<0x;i++) {
while(0 < (rdsize = read(fd,buf,LINELEN))){
//nothing here
}
lseek(fd, 0, SEEK_SET);
}
close(fd);
return 0;
}
/**/
#compile and run:
gcc test.c -o test
perf stat -d -e cache-misses ./test /proc/net/snmp
perf stat -d -e cache-misses ./test /proc/net/snmp6
perf stat -d -e cache-misses ./test /proc/net/netstat
perf stat -d -e cache-misses ./test /proc/net/sctp/snmp
perf stat -d -e cache-misses ./test /proc/net/xfrm_stat
#test results
I firstly test the correctness of data statistics.
As for performance, before the patch set:
Performance counter stats for 'system wide':
355911097 cache-misses
[40.08%]
2356829300 L1-dcache-loads
[60.04%]
355642645 L1-dcache-load-misses # 15.09% of all L1-dcache
hits [60.02%]
346544541 LLC-loads
[59.97%]
389763 LLC-load-misses #0.11% of all LL-cache
hits[40.02%]
6.245162638 seconds time elapsed
After the patch set:
===
Performance counter stats for 'system wide':
194992476 cache-misses
[40.03%]
6718051877 L1-dcache-loads
[60.07%]
194871921 L1-dcache-load-misses #2.90% of all L1-dcache
hits [60.11%]
187632232 LLC-loads
[60.04%]
464466 LLC-load-misses #0.25% of all LL-cache
hits[39.89%]
6.868422769 seconds time elapsed
The cache-miss rate can be reduced from 15% to 2.9%
Jia He (6):
proc: Reduce cache miss in {snmp,netstat}_seq_show
proc: Reduce cache miss in snmp6_seq_show
proc: Reduce cache miss in sctp_snmp_seq_show
proc: Reduce cache miss in xfrm_statistics_seq_show
ipv6: Remove useless parameter in __snmp6_fill_statsdev
net: Suppress the "Comparison to NULL could be written" warning
net/ipv4/proc.c | 110 ++-
net/ipv6/addrconf.c | 12 +++---
net/ipv6/proc.c | 47 --
net/sctp/proc.c | 15 +--
net/xfrm/xfrm_proc.c | 15 +--
5 files changed, 131 insertions(+), 68 deletions(-)
--
1.8.3.1
[RFC PATCH 4/6] proc: Reduce cache miss in xfrm_statistics_seq_show
This patch exchanges the two loop for collecting the percpu
statistics data. This can reduce cache misses by going through
all the items of each cpu sequentially.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/xfrm/xfrm_proc.c | 17 +
1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/net/xfrm/xfrm_proc.c b/net/xfrm/xfrm_proc.c
index 9c4fbd8..c9df546 100644
--- a/net/xfrm/xfrm_proc.c
+++ b/net/xfrm/xfrm_proc.c
@@ -51,11 +51,20 @@ static const struct snmp_mib xfrm_mib_list[] = {
static int xfrm_statistics_seq_show(struct seq_file *seq, void *v)
{
struct net *net = seq->private;
- int i;
- for (i = 0; xfrm_mib_list[i].name; i++)
+ int i, c;
+ unsigned long buff[LINUX_MIB_XFRMMAX];
+
+ memset(buff, 0, sizeof(unsigned long) * LINUX_MIB_XFRMMAX);
+
+ for_each_possible_cpu(c)
+ for (i = 0; xfrm_mib_list[i].name != NULL; i++)
+ buff[i] += snmp_get_cpu_field(
+ net->mib.xfrm_statistics,
+ c, xfrm_mib_list[i].entry);
+ for (i = 0; xfrm_mib_list[i].name != NULL; i++)
seq_printf(seq, "%-24s\t%lu\n", xfrm_mib_list[i].name,
- snmp_fold_field(net->mib.xfrm_statistics,
- xfrm_mib_list[i].entry));
+ buff[i]);
+
return 0;
}
--
1.8.3.1
[RFC PATCH 6/6] net: Suppress the "Comparison to NULL
This is to suppress the checkpatch.pl warning "Comparison to NULL
could be written". No functional changes here.
Signed-off-by: Jia He <hejia...@gmail.com>
---
net/ipv4/proc.c | 42 +-
net/sctp/proc.c | 4 ++--
net/xfrm/xfrm_proc.c | 4 ++--
3 files changed, 25 insertions(+), 25 deletions(-)
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index ed09566..8cbf3e0 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -355,22 +355,22 @@ static void icmp_put(struct seq_file *seq)
atomic_long_t *ptr = net->mib.icmpmsg_statistics->mibs;
seq_puts(seq, "\nIcmp: InMsgs InErrors InCsumErrors");
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " In%s", icmpmibmap[i].name);
seq_puts(seq, " OutMsgs OutErrors");
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " Out%s", icmpmibmap[i].name);
seq_printf(seq, "\nIcmp: %lu %lu %lu",
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INMSGS),
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INERRORS),
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_CSUMERRORS));
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " %lu",
atomic_long_read(ptr + icmpmibmap[i].index));
seq_printf(seq, " %lu %lu",
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTMSGS),
snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTERRORS));
- for (i = 0; icmpmibmap[i].name != NULL; i++)
+ for (i = 0; icmpmibmap[i].name; i++)
seq_printf(seq, " %lu",
atomic_long_read(ptr + (icmpmibmap[i].index |
0x100)));
}
@@ -389,7 +389,7 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
memset(buff64, 0, IPSTATS_MIB_MAX * sizeof(u64));
seq_puts(seq, "Ip: Forwarding DefaultTTL");
- for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
+ for (i = 0; snmp4_ipstats_list[i].name; i++)
seq_printf(seq, " %s", snmp4_ipstats_list[i].name);
seq_printf(seq, "\nIp: %d %d",
@@ -399,30 +399,30 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
BUILD_BUG_ON(offsetof(struct ipstats_mib, mibs) != 0);
for_each_possible_cpu(c) {
- for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
+ for (i = 0; snmp4_ipstats_list[i].name; i++)
buff64[i] += snmp_get_cpu_field64(
net->mib.ip_statistics,
c, snmp4_ipstats_list[i].entry,
offsetof(struct ipstats_mib, syncp));
}
- for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
+ for (i = 0; snmp4_ipstats_list[i].name; i++)
seq_printf(seq, " %llu", buff64[i]);
icmp_put(seq); /* RFC 2011 compatibility */
icmpmsg_put(seq);
seq_puts(seq, "\nTcp:");
- for (i = 0; snmp4_tcp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_tcp_list[i].name; i++)
seq_printf(seq, " %s", snmp4_tcp_list[i].name);
seq_puts(seq, "\nTcp:");
for_each_possible_cpu(c) {
- for (i = 0; snmp4_tcp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_tcp_list[i].name; i++)
buff[i] += snmp_get_cpu_field(net->mib.tcp_statistics,
c, snmp4_tcp_list[i].entry);
}
- for (i = 0; snmp4_tcp_list[i].name != NULL; i++) {
+ for (i = 0; snmp4_tcp_list[i].name; i++) {
/* MaxConn field is signed, RFC 2012 */
if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN)
seq_printf(seq, " %ld", buff[i]);
@@ -433,23 +433,23 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
memset(buff, 0, TCP_MIB_MAX * sizeof(unsigned long));
for_each_possible_cpu(c) {
- for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_udp_list[i].name; i++)
buff[i] += snmp_get_cpu_field(net->mib.udp_statistics,
c, snmp4_udp_list[i].entry);
}
seq_puts(seq, "\nUdp:");
- for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+ for (i = 0; snmp4_udp_list[i].name; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
seq_puts(seq, "\nUdp:");
-
[RFC PATCH 3/3] net: Remove the useless parameter of __snmp6_fill_statsdev
In commit a3a773726c9f ("net: Optimize snmp stat aggregation by walking
all the percpu data at once"), __snmp6_fill_stats64 had been optimized
by removing parameter items, so do the same for __snmp6_fill_statsdev.
Signed-off-by: Jia He <hejia...@gmail.com>
Cc: "David S. Miller" <da...@davemloft.net>
Cc: Alexey Kuznetsov <kuz...@ms2.inr.ac.ru>
Cc: James Morris <jmor...@namei.org>
Cc: Hideaki YOSHIFUJI <yoshf...@linux-ipv6.org>
Cc: Patrick McHardy <ka...@trash.net>
---
net/ipv6/addrconf.c | 12 ++--
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 1fce613..37ea2bb 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4944,18 +4944,18 @@ static inline size_t inet6_if_nlmsg_size(void)
}
static inline void __snmp6_fill_statsdev(u64 *stats, atomic_long_t *mib,
- int items, int bytes)
+ int bytes)
{
int i;
- int pad = bytes - sizeof(u64) * items;
+ int pad = bytes - sizeof(u64) * ICMP6_MIB_MAX;
BUG_ON(pad < 0);
/* Use put_unaligned() because stats may not be aligned for u64. */
- put_unaligned(items, [0]);
- for (i = 1; i < items; i++)
+ put_unaligned(ICMP6_MIB_MAX, [0]);
+ for (i = 1; i < ICMP6_MIB_MAX; i++)
put_unaligned(atomic_long_read([i]), [i]);
- memset([items], 0, pad);
+ memset([ICMP6_MIB_MAX], 0, pad);
}
static inline void __snmp6_fill_stats64(u64 *stats, void __percpu *mib,
@@ -4987,7 +4987,7 @@ static void snmp6_fill_stats(u64 *stats, struct inet6_dev
*idev, int attrtype,
offsetof(struct ipstats_mib, syncp));
break;
case IFLA_INET6_ICMP6STATS:
- __snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs,
ICMP6_MIB_MAX, bytes);
+ __snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs,
bytes);
break;
}
}
--
2.5.0
[RFC PATCH 2/3] net: Replace for_each_possible_cpu with for_each_online_cpu
In PowerPC server with large number cpus, the loop index in smt=1 could be
reduced to 1/8 compared with smt=8.
Thus cache misses can be reduced.
Signed-off-by: Jia He <hejia...@gmail.com>
Cc: "David S. Miller" <da...@davemloft.net>
Cc: Alexey Kuznetsov <kuz...@ms2.inr.ac.ru>
Cc: James Morris <jmor...@namei.org>
Cc: Hideaki YOSHIFUJI <yoshf...@linux-ipv6.org>
Cc: Patrick McHardy <ka...@trash.net>
---
net/ipv6/addrconf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 43fa8d0..1fce613 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4969,7 +4969,7 @@ static inline void __snmp6_fill_stats64(u64 *stats, void
__percpu *mib,
buff[0] = IPSTATS_MIB_MAX;
- for_each_possible_cpu(c) {
+ for_each_online_cpu(c) {
for (i = 1; i < IPSTATS_MIB_MAX; i++)
buff[i] += snmp_get_cpu_field64(mib, c, i, syncpoff);
}
--
2.5.0
[RFC PATCH 0/3] net: Improve snmp6_fill_stats
This is the follow up work of commit a3a773726c9f ("net: Optimize
snmp stat aggregation by walking all the percpu data at once")
Jia He (3):
net: Remove unnecessary memset in __snmp6_fill_stats64
net: Replace for_each_possible_cpu with for_each_online_cpu
net: Remove the useless parameter of __snmp6_fill_statsdev
net/ipv6/addrconf.c | 15 +++
1 file changed, 7 insertions(+), 8 deletions(-)
--
2.5.0
[RFC PATCH 1/3] net: Remove unnecessary memset in __snmp6_fill_stats64
buff[] will be assigned later, so memset is not necessary.
Signed-off-by: Jia He <hejia...@gmail.com>
Cc: "David S. Miller" <da...@davemloft.net>
Cc: Alexey Kuznetsov <kuz...@ms2.inr.ac.ru>
Cc: James Morris <jmor...@namei.org>
Cc: Hideaki YOSHIFUJI <yoshf...@linux-ipv6.org>
Cc: Patrick McHardy <ka...@trash.net>
---
net/ipv6/addrconf.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index ab3e796..43fa8d0 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4967,7 +4967,6 @@ static inline void __snmp6_fill_stats64(u64 *stats, void
__percpu *mib,
BUG_ON(pad < 0);
- memset(buff, 0, sizeof(buff));
buff[0] = IPSTATS_MIB_MAX;
for_each_possible_cpu(c) {
--
2.5.0
