Re: [PATCH v6 0/7] Reduce cache miss for snmp_fold_field

2016-09-30 Thread David Miller 
From: Jia He 
Date: Fri, 30 Sep 2016 11:28:57 +0800

> 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.
 ...

Series applied, thank you.

Re: [PATCH v6 0/7] Reduce cache miss for snmp_fold_field

2016-09-30 Thread David Miller 
From: Jia He 
Date: Fri, 30 Sep 2016 11:28:57 +0800

> 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.
 ...

Series applied, thank you.

[PATCH v6 0/7] Reduce cache miss for snmp_fold_field

2016-09-29 Thread Jia He 
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 v6 0/7] Reduce cache miss for snmp_fold_field

2016-09-29 Thread Jia He 
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