Re: [Crash-utility] [PATCH RFC] Add "kmem -r" to display accumulated slab statistics like /proc/slabinfo

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.

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-hagio(a)ab.jp.nec.com&gt; --- 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(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility