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

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 <tj(a)kernel.org&gt; 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-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 > > -- > Crash-utility mailing list > Crash-utility(a)redhat.com > https://www.redhat.com/mailman/listinfo/crash-utility > -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility