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

Dave Anderson anderson at redhat.com
Fri Aug 24 19:18:46 UTC 2018


Hi Kazu,

Nicely done -- queued for crash-7.2.4:

  https://github.com/crash-utility/crash/commit/e541c5ca2766d6d6934f435955d70aa7b3fd52b0

Thanks,
  Dave


----- Original Message -----
> 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 at 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-hagio at 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 at redhat.com
> >> https://www.redhat.com/mailman/listinfo/crash-utility
> > 
> > --
> > Crash-utility mailing list
> > Crash-utility at redhat.com
> > https://www.redhat.com/mailman/listinfo/crash-utility
> > 
> 
> --
> Crash-utility mailing list
> Crash-utility at redhat.com
> https://www.redhat.com/mailman/listinfo/crash-utility
> 




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