On 8/23/2018 4:31 PM, Dave Anderson wrote:
>
>
> ----- Original Message -----
>> Nowadays, the "kmem -s" output can become very long vertically too,
>> due to the memcg kmem caches. It look like the longer a system has
>> run, the longer it becomes.
>>
>> crash> kmem -s | wc -l
>> 19855
>>
>> On the other hand, since /proc/slabinfo accumulates the values of
>> each slab_root_caches and its children, it's still short relatively.
>> And I think there are many cases that support folks want to see the
>> accumulated values like /proc/slabinfo from vmcore, in order to
>> grasp the overview of slab activity quickly.
>>
>> We can use something like the attached script to accumulate them,
>> but I believe it would be more useful to implement it in crash.
>>
>> This patch introduces the "kmem -r" option to imitate /proc/slabinfo,
>> but it is limited to CONFIG_SLUB for now.
>
> And it looks like it's limited to Linux 4.11 and later, correct?
Yes.
The patch below introduced the slab_root_caches list at Linux 4.11.
commit 510ded33e075c2bd662b1efab0110f4240325fc9
Author: Tejun Heo <t...@kernel.org>
Date: Wed Feb 22 15:41:24 2017 -0800
slab: implement slab_root_caches list
Thanks,
Kazu
>
> Thanks,
> Dave
>
>
>
>>
>> I tested this patch with the kmem-s2r.awk script:
>>
>> crash> kmem -s | awk -f kmem-s2r.awk > kmem-s2r.txt
>> crash> kmem -r > kmem-r.txt
>>
>> # diff -u kmem-s2r.txt kmem-r.txt
>>
>> Supported:
>> crash> kmem -r
>> crash> kmem -r list
>> crash> kmem -r <slab name>
>>
>> Signed-off-by: Kazuhito Hagio <k-ha...@ab.jp.nec.com>
>> ---
>> defs.h | 5 ++
>> help.c | 10 +--
>> memory.c | 219
>> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++------
>> symbols.c | 9 +++
>> 4 files changed, 220 insertions(+), 23 deletions(-)
>>
>> diff --git a/defs.h b/defs.h
>> index 6fdb478..8687ff1 100644
>> --- a/defs.h
>> +++ b/defs.h
>> @@ -2032,6 +2032,10 @@ struct offset_table { /* stash of
>> commonly-used offsets */
>> long bpf_prog_aux_user;
>> long user_struct_uid;
>> long idr_cur;
>> + long kmem_cache_memcg_params;
>> + long memcg_cache_params___root_caches_node;
>> + long memcg_cache_params_children;
>> + long memcg_cache_params_children_node;
>> };
>>
>> struct size_table { /* stash of commonly-used sizes */
>> @@ -2438,6 +2442,7 @@ struct vm_table { /* kernel VM-related
>> data */
>> #define PAGEFLAGS (0x4000000)
>> #define SLAB_OVERLOAD_PAGE (0x8000000)
>> #define SLAB_CPU_CACHE (0x10000000)
>> +#define SLAB_ROOT_CACHES (0x20000000)
>>
>> #define IS_FLATMEM() (vt->flags & FLATMEM)
>> #define IS_DISCONTIGMEM() (vt->flags & DISCONTIGMEM)
>> diff --git a/help.c b/help.c
>> index aeeb056..ee8b999 100644
>> --- a/help.c
>> +++ b/help.c
>> @@ -6448,7 +6448,7 @@ char *help_kmem[] = {
>> "kmem",
>> "kernel memory",
>> "[-f|-F|-c|-C|-i|-v|-V|-n|-z|-o|-h] [-p | -m member[,member]]\n"
>> -" [[-s|-S] [slab] [-I slab[,slab]]] [-g [flags]] [[-P] address]]",
>> +" [[-s|-S|-r] [slab] [-I slab[,slab]]] [-g [flags]] [[-P] address]]",
>> " This command displays information about the use of kernel memory.\n",
>> " -f displays the contents of the system free memory headers.",
>> " also verifies that the page count equals nr_free_pages.",
>> @@ -6490,10 +6490,12 @@ char *help_kmem[] = {
>> " slab data for each per-cpu slab is displayed, along with the",
>> " address of each kmem_cache_node, its count of full and
>> partial",
>> " slabs, and a list of all tracked slabs.",
>> -" slab when used with -s or -S, limits the command to only the slab
>> cache",
>> -" of name \"slab\". If the slab argument is \"list\", then",
>> +" -r displays accumulated kmalloc() slab data of each
>> slab_root_caches",
>> +" and its children. Available only if CONFIG_SLUB for now.",
>> +" slab when used with -s, -S or -r, limits the command to only the
>> slab",
>> +" cache of name \"slab\". If the slab argument is \"list\",
>> then",
>> " all slab cache names and addresses are listed.",
>> -" -I slab when used with -s or -S, one or more slab cache names in a",
>> +" -I slab when used with -s, -S or -r, one or more slab cache names in
>> a",
>> " comma-separated list may be specified as slab caches to
>> ignore.",
>> " -g displays the enumerator value of all bits in the page
>> structure's",
>> " \"flags\" field.",
>> diff --git a/memory.c b/memory.c
>> index e02ba68..1501b21 100644
>> --- a/memory.c
>> +++ b/memory.c
>> @@ -167,12 +167,12 @@ static int kmem_cache_downsize(void);
>> static int ignore_cache(struct meminfo *, char *);
>> static char *is_kmem_cache_addr(ulong, char *);
>> static char *is_kmem_cache_addr_common(ulong, char *);
>> -static void kmem_cache_list(void);
>> +static void kmem_cache_list(struct meminfo *);
>> static void dump_kmem_cache(struct meminfo *);
>> static void dump_kmem_cache_percpu_v1(struct meminfo *);
>> static void dump_kmem_cache_percpu_v2(struct meminfo *);
>> static void dump_kmem_cache_slub(struct meminfo *);
>> -static void kmem_cache_list_common(void);
>> +static void kmem_cache_list_common(struct meminfo *);
>> static ulong get_cpu_slab_ptr(struct meminfo *, int, ulong *);
>> static unsigned int oo_order(ulong);
>> static unsigned int oo_objects(ulong);
>> @@ -276,6 +276,8 @@ static int generic_read_dumpfile(ulonglong, void *, long,
>> char *, ulong);
>> static int generic_write_dumpfile(ulonglong, void *, long, char *, ulong);
>> static int page_to_nid(ulong);
>> static int get_kmem_cache_list(ulong **);
>> +static int get_kmem_cache_root_list(ulong **);
>> +static int get_kmem_cache_child_list(ulong **, ulong);
>> static int get_kmem_cache_slub_data(long, struct meminfo *);
>> static ulong compound_head(ulong);
>> static long count_partial(ulong, struct meminfo *, ulong *);
>> @@ -815,6 +817,23 @@ vm_init(void)
>> "kmem_slab_s", "s_magic");
>> }
>>
>> + if (kernel_symbol_exists("slab_root_caches")) {
>> + MEMBER_OFFSET_INIT(kmem_cache_memcg_params,
>> + "kmem_cache", "memcg_params");
>> + MEMBER_OFFSET_INIT(memcg_cache_params___root_caches_node,
>> + "memcg_cache_params", "__root_caches_node");
>> + MEMBER_OFFSET_INIT(memcg_cache_params_children,
>> + "memcg_cache_params", "children");
>> + MEMBER_OFFSET_INIT(memcg_cache_params_children_node,
>> + "memcg_cache_params", "children_node");
>> +
>> + if (VALID_MEMBER(kmem_cache_memcg_params)
>> + && VALID_MEMBER(memcg_cache_params___root_caches_node)
>> + && VALID_MEMBER(memcg_cache_params_children)
>> + && VALID_MEMBER(memcg_cache_params_children_node))
>> + vt->flags |= SLAB_ROOT_CACHES;
>> + }
>> +
>> if (!kt->kernel_NR_CPUS) {
>> if (enumerator_value("WORK_CPU_UNBOUND", (long *)&value1))
>> kt->kernel_NR_CPUS = (int)value1;
>> @@ -4713,6 +4732,7 @@ get_task_mem_usage(ulong task, struct task_mem_usage
>> *tm)
>> #define SLAB_OVERLOAD_PAGE_PTR (ADDRESS_SPECIFIED << 24)
>> #define SLAB_BITFIELD (ADDRESS_SPECIFIED << 25)
>> #define SLAB_GATHER_FAILURE (ADDRESS_SPECIFIED << 26)
>> +#define GET_SLAB_ROOT_CACHES (ADDRESS_SPECIFIED << 27)
>>
>> #define GET_ALL \
>> (GET_SHARED_PAGES|GET_TOTALRAM_PAGES|GET_BUFFERS_PAGES|GET_SLAB_PAGES)
>> @@ -4724,6 +4744,7 @@ cmd_kmem(void)
>> int c;
>> int sflag, Sflag, pflag, fflag, Fflag, vflag, zflag, oflag, gflag;
>> int nflag, cflag, Cflag, iflag, lflag, Lflag, Pflag, Vflag, hflag;
>> + int rflag;
>> struct meminfo meminfo;
>> ulonglong value[MAXARGS];
>> char buf[BUFSIZE];
>> @@ -4733,13 +4754,13 @@ cmd_kmem(void)
>> spec_addr = 0;
>> sflag = Sflag = pflag = fflag = Fflag = Pflag = zflag = oflag =
>> 0;
>> vflag = Cflag = cflag = iflag = nflag = lflag = Lflag = Vflag = 0;
>> - gflag = hflag = 0;
>> + gflag = hflag = rflag = 0;
>> escape = FALSE;
>> BZERO(&meminfo, sizeof(struct meminfo));
>> BZERO(&value[0], sizeof(ulonglong)*MAXARGS);
>> pc->curcmd_flags &= ~HEADER_PRINTED;
>>
>> - while ((c = getopt(argcnt, args, "gI:sSFfm:pvczCinl:L:PVoh")) !=
>> EOF) {
>> + while ((c = getopt(argcnt, args, "gI:sSrFfm:pvczCinl:L:PVoh")) !=
>> EOF) {
>> switch(c)
>> {
>> case 'V':
>> @@ -4775,11 +4796,15 @@ cmd_kmem(void)
>> break;
>>
>> case 's':
>> - sflag = 1; Sflag = 0;
>> + sflag = 1; Sflag = rflag = 0;
>> break;
>>
>> case 'S':
>> - Sflag = 1; sflag = 0;
>> + Sflag = 1; sflag = rflag = 0;
>> + break;
>> +
>> + case 'r':
>> + rflag = 1; sflag = Sflag = 0;
>> break;
>>
>> case 'F':
>> @@ -4859,12 +4884,13 @@ cmd_kmem(void)
>> cmd_usage(pc->curcmd, SYNOPSIS);
>>
>> if ((sflag + Sflag + pflag + fflag + Fflag + Vflag + oflag +
>> - vflag + Cflag + cflag + iflag + lflag + Lflag + gflag + hflag) >
>> 1) {
>> + vflag + Cflag + cflag + iflag + lflag + Lflag + gflag +
>> + hflag + rflag) > 1) {
>> error(INFO, "only one flag allowed!\n");
>> cmd_usage(pc->curcmd, SYNOPSIS);
>> }
>>
>> - if (sflag || Sflag || !(vt->flags & KMEM_CACHE_INIT))
>> + if (sflag || Sflag || rflag || !(vt->flags & KMEM_CACHE_INIT))
>> kmem_cache_init();
>>
>> while (args[optind]) {
>> @@ -4881,7 +4907,7 @@ cmd_kmem(void)
>> escape = TRUE;
>> } else
>> meminfo.reqname = args[optind];
>> - if (!sflag && !Sflag)
>> + if (!sflag && !Sflag && !rflag)
>> cmd_usage(pc->curcmd, SYNOPSIS);
>> }
>>
>> @@ -4994,7 +5020,7 @@ cmd_kmem(void)
>> * no value arguments allowed!
>> */
>> if (zflag || nflag || iflag || Fflag || Cflag || Lflag ||
>> - Vflag || oflag || hflag) {
>> + Vflag || oflag || hflag || rflag) {
>> error(INFO,
>> "no address arguments allowed with this option\n");
>> cmd_usage(pc->curcmd, SYNOPSIS);
>> @@ -5030,9 +5056,17 @@ cmd_kmem(void)
>> if (hflag == 1)
>> dump_hstates();
>>
>> - if (sflag == 1) {
>> + if (sflag == 1 || rflag == 1) {
>> + if (rflag) {
>> + if (!((vt->flags & KMALLOC_SLUB)
>> + && (vt->flags & SLAB_ROOT_CACHES)))
>> + error(FATAL,
>> + "-r option doesn't support this kernel\n");
>> +
>> + meminfo.flags = GET_SLAB_ROOT_CACHES;
>> + }
>> if (!escape && STREQ(meminfo.reqname, "list"))
>> - kmem_cache_list();
>> + kmem_cache_list(&meminfo);
>> else if (vt->flags & KMEM_CACHE_UNAVAIL)
>> error(FATAL,
>> "kmem cache slab subsystem not available\n");
>> @@ -5042,7 +5076,7 @@ cmd_kmem(void)
>>
>> if (Sflag == 1) {
>> if (STREQ(meminfo.reqname, "list"))
>> - kmem_cache_list();
>> + kmem_cache_list(&meminfo);
>> else if (vt->flags & KMEM_CACHE_UNAVAIL)
>> error(FATAL,
>> "kmem cache slab subsystem not available\n");
>> @@ -5092,7 +5126,8 @@ cmd_kmem(void)
>>
>> if (!(sflag + Sflag + pflag + fflag + Fflag + vflag +
>> Vflag + zflag + oflag + cflag + Cflag + iflag +
>> - nflag + lflag + Lflag + gflag + hflag + meminfo.calls))
>> + nflag + lflag + Lflag + gflag + hflag + rflag +
>> + meminfo.calls))
>> cmd_usage(pc->curcmd, SYNOPSIS);
>>
>> }
>> @@ -9117,7 +9152,7 @@ is_kmem_cache_addr(ulong vaddr, char *kbuf)
>> * dumps all slab cache names and their addresses.
>> */
>> static void
>> -kmem_cache_list(void)
>> +kmem_cache_list(struct meminfo *mi)
>> {
>> ulong cache, cache_cache, name;
>> long next_offset, name_offset;
>> @@ -9132,7 +9167,7 @@ kmem_cache_list(void)
>> }
>>
>> if (vt->flags & (KMALLOC_SLUB|KMALLOC_COMMON)) {
>> - kmem_cache_list_common();
>> + kmem_cache_list_common(mi);
>> return;
>> }
>>
>> @@ -13564,6 +13599,8 @@ dump_vm_table(int verbose)
>> fprintf(fp, "%sSLAB_OVERLOAD_PAGE", others++ ? "|" : "");\
>> if (vt->flags & SLAB_CPU_CACHE)
>> fprintf(fp, "%sSLAB_CPU_CACHE", others++ ? "|" : "");\
>> + if (vt->flags & SLAB_ROOT_CACHES)
>> + fprintf(fp, "%sSLAB_ROOT_CACHES", others++ ? "|" : "");\
>> if (vt->flags & USE_VMAP_AREA)
>> fprintf(fp, "%sUSE_VMAP_AREA", others++ ? "|" : "");\
>> if (vt->flags & CONFIG_NUMA)
>> @@ -18044,14 +18081,17 @@ kmem_cache_init_slub(void)
>> }
>>
>> static void
>> -kmem_cache_list_common(void)
>> +kmem_cache_list_common(struct meminfo *mi)
>> {
>> int i, cnt;
>> ulong *cache_list;
>> ulong name;
>> char buf[BUFSIZE];
>>
>> - cnt = get_kmem_cache_list(&cache_list);
>> + if (mi->flags & GET_SLAB_ROOT_CACHES)
>> + cnt = get_kmem_cache_root_list(&cache_list);
>> + else
>> + cnt = get_kmem_cache_list(&cache_list);
>>
>> for (i = 0; i < cnt; i++) {
>> fprintf(fp, "%lx ", cache_list[i]);
>> @@ -18087,7 +18127,11 @@ dump_kmem_cache_slub(struct meminfo *si)
>> }
>>
>> order = objects = 0;
>> - si->cache_count = get_kmem_cache_list(&si->cache_list);
>> + if (si->flags & GET_SLAB_ROOT_CACHES)
>> + si->cache_count = get_kmem_cache_root_list(&si->cache_list);
>> + else
>> + si->cache_count = get_kmem_cache_list(&si->cache_list);
>> +
>> si->cache_buf = GETBUF(SIZE(kmem_cache));
>>
>> if (VALID_MEMBER(page_objects) &&
>> @@ -18168,6 +18212,79 @@ dump_kmem_cache_slub(struct meminfo *si)
>> !get_kmem_cache_slub_data(GET_SLUB_OBJECTS, si))
>> si->flags |= SLAB_GATHER_FAILURE;
>>
>> + /* accumulate children's slabinfo */
>> + if (si->flags & GET_SLAB_ROOT_CACHES) {
>> + struct meminfo *mi;
>> + int j;
>> + char buf2[BUFSIZE];
>> +
>> + mi = (struct meminfo *)GETBUF(sizeof(struct meminfo));
>> + memcpy(mi, si, sizeof(struct meminfo));
>> +
>> + mi->cache_count =
>> get_kmem_cache_child_list(&mi->cache_list,
>> + si->cache_list[i]);
>> +
>> + if (!mi->cache_count)
>> + goto no_children;
>> +
>> + mi->cache_buf = GETBUF(SIZE(kmem_cache));
>> +
>> + for (j = 0; j < mi->cache_count; j++) {
>> + BZERO(mi->cache_buf, SIZE(kmem_cache));
>> + if (!readmem(mi->cache_list[j], KVADDR,
>> mi->cache_buf,
>> + SIZE(kmem_cache), "kmem_cache buffer",
>> + RETURN_ON_ERROR|RETURN_PARTIAL))
>> + continue;
>> +
>> + name = ULONG(mi->cache_buf +
>> OFFSET(kmem_cache_name));
>> + if (!read_string(name, buf2, BUFSIZE-1))
>> + sprintf(buf2, "(unknown)");
>> +
>> + objsize = UINT(mi->cache_buf +
>> OFFSET(kmem_cache_objsize));
>> + size = UINT(mi->cache_buf +
>> OFFSET(kmem_cache_size));
>> + offset = UINT(mi->cache_buf +
>> OFFSET(kmem_cache_offset));
>> + if (VALID_MEMBER(kmem_cache_objects)) {
>> + objects = UINT(mi->cache_buf +
>> + OFFSET(kmem_cache_objects));
>> + order = UINT(mi->cache_buf +
>> OFFSET(kmem_cache_order));
>> + } else if (VALID_MEMBER(kmem_cache_oo)) {
>> + oo = ULONG(mi->cache_buf +
>> OFFSET(kmem_cache_oo));
>> + objects = oo_objects(oo);
>> + order = oo_order(oo);
>> + } else
>> + error(FATAL, "cannot determine "
>> + "kmem_cache objects/order
>> values\n");
>> +
>> + mi->cache = mi->cache_list[j];
>> + mi->curname = buf2;
>> + mi->objsize = objsize;
>> + mi->size = size;
>> + mi->objects = objects;
>> + mi->slabsize = (PAGESIZE() << order);
>> + mi->inuse = mi->num_slabs = 0;
>> + mi->slab_offset = offset;
>> + mi->random = VALID_MEMBER(kmem_cache_random) ?
>> + ULONG(mi->cache_buf +
>> OFFSET(kmem_cache_random)) : 0;
>> +
>> + if (!get_kmem_cache_slub_data(GET_SLUB_SLABS,
>> mi) ||
>> + !get_kmem_cache_slub_data(GET_SLUB_OBJECTS,
>> mi)) {
>> + si->flags |= SLAB_GATHER_FAILURE;
>> + continue;
>> + }
>> +
>> + si->inuse += mi->inuse;
>> + si->free += mi->free;
>> + si->num_slabs += mi->num_slabs;
>> +
>> + if (CRASHDEBUG(1))
>> + dump_kmem_cache_info(mi);
>> + }
>> + FREEBUF(mi->cache_buf);
>> + FREEBUF(mi->cache_list);
>> +no_children:
>> + FREEBUF(mi);
>> + }
>> +
>> DUMP_KMEM_CACHE_INFO();
>>
>> if (si->flags & SLAB_GATHER_FAILURE) {
>> @@ -18964,6 +19081,70 @@ get_kmem_cache_list(ulong **cache_buf)
>> return cnt;
>> }
>>
>> +static int
>> +get_kmem_cache_root_list(ulong **cache_buf)
>> +{
>> + int cnt;
>> + ulong vaddr;
>> + struct list_data list_data, *ld;
>> +
>> + get_symbol_data("slab_root_caches", sizeof(void *), &vaddr);
>> +
>> + ld = &list_data;
>> + BZERO(ld, sizeof(struct list_data));
>> + ld->flags |= LIST_ALLOCATE;
>> + ld->start = vaddr;
>> + ld->list_head_offset = OFFSET(kmem_cache_memcg_params)
>> + + OFFSET(memcg_cache_params___root_caches_node);
>> + ld->end = symbol_value("slab_root_caches");
>> + if (CRASHDEBUG(3))
>> + ld->flags |= VERBOSE;
>> +
>> + cnt = do_list(ld);
>> + *cache_buf = ld->list_ptr;
>> +
>> + return cnt;
>> +}
>> +
>> +static int
>> +get_kmem_cache_child_list(ulong **cache_buf, ulong root)
>> +{
>> + int cnt;
>> + ulong vaddr, children;
>> + struct list_data list_data, *ld;
>> +
>> + children = root + OFFSET(kmem_cache_memcg_params)
>> + + OFFSET(memcg_cache_params_children);
>> +
>> + readmem(children, KVADDR, &vaddr, sizeof(ulong),
>> + "kmem_cache.memcg_params.children",
>> + FAULT_ON_ERROR);
>> +
>> + /*
>> + * When no children, since there is the difference of offset
>> + * of children list between root and child, do_list returns
>> + * an incorrect cache_buf[0]. So we determine wheather it has
>> + * children or not with the value of list_head.next.
>> + */
>> + if (children == vaddr)
>> + return 0;
>> +
>> + ld = &list_data;
>> + BZERO(ld, sizeof(struct list_data));
>> + ld->flags |= LIST_ALLOCATE;
>> + ld->start = vaddr;
>> + ld->list_head_offset =
>> + OFFSET(kmem_cache_memcg_params)
>> + + OFFSET(memcg_cache_params_children_node);
>> + ld->end = children;
>> + if (CRASHDEBUG(3))
>> + ld->flags |= VERBOSE;
>> +
>> + cnt = do_list(ld);
>> + *cache_buf = ld->list_ptr;
>> +
>> + return cnt;
>> +}
>>
>> /*
>> * Get the address of the head page of a compound page.
>> diff --git a/symbols.c b/symbols.c
>> index bee60ba..2e6713a 100644
>> --- a/symbols.c
>> +++ b/symbols.c
>> @@ -9451,6 +9451,15 @@ dump_offset_table(char *spec, ulong makestruct)
>> fprintf(fp, " kmem_cache_flags: %ld\n",
>> OFFSET(kmem_cache_flags));
>>
>> + fprintf(fp, " kmem_cache_memcg_params: %ld\n",
>> + OFFSET(kmem_cache_memcg_params));
>> + fprintf(fp, "memcg_cache_params___root_caches_node: %ld\n",
>> + OFFSET(memcg_cache_params___root_caches_node));
>> + fprintf(fp, " memcg_cache_params_children: %ld\n",
>> + OFFSET(memcg_cache_params_children));
>> + fprintf(fp, " memcg_cache_params_children_node: %ld\n",
>> + OFFSET(memcg_cache_params_children_node));
>> +
>> fprintf(fp, " net_device_next: %ld\n",
>> OFFSET(net_device_next));
>> fprintf(fp, " net_device_name: %ld\n",
>> --
>> 1.8.3.1
>>
>> --
>> Crash-utility mailing list
>> Crash-utility@redhat.com
>> https://www.redhat.com/mailman/listinfo/crash-utility
>
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