[PATCH 0/2] tools/mm/slabinfo: report sheaf and barn statistics

[PATCH 0/2] tools/mm/slabinfo: report sheaf and barn statistics

[Seongjun Hong]

Since commit 2d517aa09bbc ("slab: add opt-in caching layer of percpu
sheaves"), kernel exposes sheaf and barn statistics through sysfs but
slabinfo did not utilize this information. Make slabinfo report
kmem_cache statistics including sheaf and barn counters.

Signed-off-by: Seongjun Hong <hsj0512@snu.ac.kr>
---
Seongjun Hong (2):
      tools/mm/slabinfo: refactor slab attribute reading
      tools/mm/slabinfo: report percpu sheaves and barn statistics

 tools/mm/slabinfo.c | 303 ++++++++++++++++++++++++++++++++--------------------
 1 file changed, 189 insertions(+), 114 deletions(-)
---
base-commit: 9b87fdc9af2fbfcdb5c24a64139685ef80f6573f
change-id: 20260921-tools-mm-update-slabinfo-8eab37191831

Best regards,
-- 
Best regards,
Seongjun Hong

[PATCH 1/2] tools/mm/slabinfo: refactor slab attribute reading

[Seongjun Hong]

The fields of struct slabinfo were mixed with deprecated sysfs files,
which looks complicated. Organize every field of struct slabinfo by
config option and the attribute order in mm/slub.c's slab_attrs[]. Because
slabinfo should be able to run on previous kernel releases, leave the
deprecated members for this time.

read_slab_dir() had ~50 lines of attribute reads inlined. Move them to a
new fill_slabinfo() helper so that directory walk and per-cache
attribute reading are separated.

Fold get_obj_and_str() and decode_numa_list() into get_obj_and_decode()
to avoid unnecessary strdup() and leave only one member assignment in
fill_slabinfo() for each sysfs file.

Make broken statements into a single line for better readibility.

Remove alias field from struct slabinfo because it is initialized to 0
and never updated. The only usage of this field "if (slab->alias)" is dead.

No functional change intended.

Signed-off-by: Seongjun Hong <hsj0512@snu.ac.kr>
---
 tools/mm/slabinfo.c | 245 ++++++++++++++++++++++++++++------------------------
 1 file changed, 131 insertions(+), 114 deletions(-)

diff --git a/tools/mm/slabinfo.c b/tools/mm/slabinfo.c
index 48d1ee8b0e81..84359d628f2e 100644
--- a/tools/mm/slabinfo.c
+++ b/tools/mm/slabinfo.c
@@ -27,25 +27,49 @@
 
 struct slabinfo {
 	char *name;
-	int alias;
 	int refs;
-	int aliases, align, cache_dma, cpu_slabs, destroy_by_rcu;
-	unsigned int hwcache_align, object_size, objs_per_slab;
-	unsigned int sanity_checks, slab_size, store_user, trace;
-	int order, poison, reclaim_account, red_zone;
-	unsigned long partial, objects, slabs, objects_partial, total_objects;
+	int numa_slabs[MAX_NODES];
+	int numa_partial[MAX_NODES];
+
+	unsigned int slab_size, object_size;
+	unsigned int objs_per_slab, order;
+	unsigned long objects_partial, partial;
+	int aliases;
+	unsigned int align;
+	int hwcache_align;
+	int reclaim_account;
+	int destroy_by_rcu;
+
+	/* CONFIG_SLUB_DEBUG */
+	unsigned long total_objects, objects, slabs;
+	int sanity_checks, trace, red_zone, poison, store_user;
+
+	/* CONFIG_ZONE_DMA */
+	int cache_dma;
+
+	/* CONFIG_SLUB_STATS */
 	unsigned long alloc_fastpath, alloc_slowpath;
 	unsigned long free_fastpath, free_slowpath;
-	unsigned long free_frozen, free_add_partial, free_remove_partial;
-	unsigned long alloc_from_partial, alloc_slab, free_slab, alloc_refill;
-	unsigned long cpuslab_flush, deactivate_full, deactivate_empty;
+	unsigned long free_add_partial, free_remove_partial;
+	unsigned long alloc_slab, alloc_node_mismatch, free_slab;
+	unsigned long order_fallback;
+	unsigned long cmpxchg_double_fail;
+
+	/*
+	 * Deprecated files:
+	 * No STAT_ATTR()/SLAB_ATTR() for these exists in mm/slub.c's
+	 * slab_attrs[] anymore. Although cpu_slabs remains as a file,
+	 * it is also outdated and always prints 0. Keep these for backward
+	 * compatibility, but they should be removed later.
+	 */
+	int cpu_slabs;
+	unsigned long free_frozen;
 	unsigned long deactivate_to_head, deactivate_to_tail;
-	unsigned long deactivate_remote_frees, order_fallback;
-	unsigned long cmpxchg_double_cpu_fail, cmpxchg_double_fail;
-	unsigned long alloc_node_mismatch, deactivate_bypass;
+	unsigned long alloc_from_partial, alloc_refill;
+	unsigned long cpuslab_flush, deactivate_full, deactivate_empty;
+	unsigned long deactivate_remote_frees, deactivate_bypass;
+	unsigned long cmpxchg_double_cpu_fail;
 	unsigned long cpu_partial_alloc, cpu_partial_free;
-	int numa[MAX_NODES];
-	int numa_partial[MAX_NODES];
 } slabinfo[MAX_SLABS];
 
 struct aliasinfo {
@@ -174,6 +198,30 @@ static unsigned long read_obj(const char *name)
 	return strlen(buffer);
 }
 
+static void decode_numa_list(int *numa, char *t)
+{
+	int node;
+	int nr;
+
+	memset(numa, 0, MAX_NODES * sizeof(int));
+
+	if (!t)
+		return;
+
+	while (*t == 'N') {
+		t++;
+		node = strtoul(t, &t, 10);
+		if (*t == '=') {
+			t++;
+			nr = strtoul(t, &t, 10);
+			numa[node] = nr;
+			if (node > highest_node)
+				highest_node = node;
+		}
+		while (*t == ' ')
+			t++;
+	}
+}
 
 /*
  * Get the contents of an attribute
@@ -186,21 +234,19 @@ static unsigned long get_obj(const char *name)
 	return atol(buffer);
 }
 
-static unsigned long get_obj_and_str(const char *name, char **x)
+static unsigned long get_obj_and_decode(int *numa, const char *name)
 {
 	unsigned long result = 0;
 	char *p;
 
-	*x = NULL;
-
 	if (!read_obj(name))
 		return 0;
 
 	result = strtoul(buffer, &p, 10);
 	while (*p == ' ')
 		p++;
-	if (*p)
-		*x = strdup(p);
+
+	decode_numa_list(numa, p);
 	return result;
 }
 
@@ -293,31 +339,6 @@ static int store_size(char *buffer, unsigned long value)
 	return n;
 }
 
-static void decode_numa_list(int *numa, char *t)
-{
-	int node;
-	int nr;
-
-	memset(numa, 0, MAX_NODES * sizeof(int));
-
-	if (!t)
-		return;
-
-	while (*t == 'N') {
-		t++;
-		node = strtoul(t, &t, 10);
-		if (*t == '=') {
-			t++;
-			nr = strtoul(t, &t, 10);
-			numa[node] = nr;
-			if (node > highest_node)
-				highest_node = node;
-		}
-		while (*t == ' ')
-			t++;
-	}
-}
-
 static void slab_validate(struct slabinfo *s)
 {
 	if (strcmp(s->name, "*") == 0)
@@ -410,7 +431,7 @@ static void slab_numa(struct slabinfo *s, int mode)
 	for(node = 0; node <= highest_node; node++) {
 		char b[20];
 
-		store_size(b, s->numa[node]);
+		store_size(b, s->numa_slabs[node]);
 		printf(" %4s", b);
 	}
 	printf("\n");
@@ -1210,6 +1231,57 @@ static int slab_mismatch(char *slab)
 	return regexec(&pattern, slab, 0, NULL, 0);
 }
 
+static void fill_slabinfo(struct slabinfo *slab, const char *name)
+{
+	slab->name = strdup(name);
+	slab->refs = 0;
+	slab->aliases = get_obj("aliases");
+	slab->align = get_obj("align");
+	slab->cache_dma = get_obj("cache_dma");
+	slab->cpu_slabs = get_obj("cpu_slabs");
+	slab->destroy_by_rcu = get_obj("destroy_by_rcu");
+	slab->hwcache_align = get_obj("hwcache_align");
+	slab->object_size = get_obj("object_size");
+	slab->objects = get_obj("objects");
+	slab->objects_partial = get_obj("objects_partial");
+	slab->total_objects = get_obj("total_objects");
+	slab->objs_per_slab = get_obj("objs_per_slab");
+	slab->order = get_obj("order");
+	slab->partial = get_obj_and_decode(slab->numa_partial, "partial");
+	slab->poison = get_obj("poison");
+	slab->reclaim_account = get_obj("reclaim_account");
+	slab->red_zone = get_obj("red_zone");
+	slab->sanity_checks = get_obj("sanity_checks");
+	slab->slab_size = get_obj("slab_size");
+	slab->slabs = get_obj_and_decode(slab->numa_slabs, "slabs");
+	slab->store_user = get_obj("store_user");
+	slab->trace = get_obj("trace");
+	slab->alloc_fastpath = get_obj("alloc_fastpath");
+	slab->alloc_slowpath = get_obj("alloc_slowpath");
+	slab->free_fastpath = get_obj("free_fastpath");
+	slab->free_slowpath = get_obj("free_slowpath");
+	slab->free_frozen = get_obj("free_frozen");
+	slab->free_add_partial = get_obj("free_add_partial");
+	slab->free_remove_partial = get_obj("free_remove_partial");
+	slab->alloc_from_partial = get_obj("alloc_from_partial");
+	slab->alloc_slab = get_obj("alloc_slab");
+	slab->alloc_refill = get_obj("alloc_refill");
+	slab->free_slab = get_obj("free_slab");
+	slab->cpuslab_flush = get_obj("cpuslab_flush");
+	slab->deactivate_full = get_obj("deactivate_full");
+	slab->deactivate_empty = get_obj("deactivate_empty");
+	slab->deactivate_to_head = get_obj("deactivate_to_head");
+	slab->deactivate_to_tail = get_obj("deactivate_to_tail");
+	slab->deactivate_remote_frees = get_obj("deactivate_remote_frees");
+	slab->order_fallback = get_obj("order_fallback");
+	slab->cmpxchg_double_cpu_fail = get_obj("cmpxchg_double_cpu_fail");
+	slab->cmpxchg_double_fail = get_obj("cmpxchg_double_fail");
+	slab->cpu_partial_alloc = get_obj("cpu_partial_alloc");
+	slab->cpu_partial_free = get_obj("cpu_partial_free");
+	slab->alloc_node_mismatch = get_obj("alloc_node_mismatch");
+	slab->deactivate_bypass = get_obj("deactivate_bypass");
+}
+
 static void read_slab_dir(void)
 {
 	DIR *dir;
@@ -1217,7 +1289,6 @@ static void read_slab_dir(void)
 	struct slabinfo *slab = slabinfo;
 	struct aliasinfo *alias = aliasinfo;
 	char *p;
-	char *t;
 	int count;
 
 	if (chdir("/sys/kernel/slab") && chdir("/sys/slab"))
@@ -1226,14 +1297,14 @@ static void read_slab_dir(void)
 	dir = opendir(".");
 	while ((de = readdir(dir))) {
 		if (de->d_name[0] == '.' ||
-			(de->d_name[0] != ':' && slab_mismatch(de->d_name)))
-				continue;
+		    (de->d_name[0] != ':' && slab_mismatch(de->d_name)))
+			continue;
 		switch (de->d_type) {
-		   case DT_LNK:
+		case DT_LNK:
 			if (alias - aliasinfo == MAX_ALIASES)
 				fatal("Too many aliases\n");
 			alias->name = strdup(de->d_name);
-			count = readlink(de->d_name, buffer, sizeof(buffer)-1);
+			count = readlink(de->d_name, buffer, sizeof(buffer) - 1);
 
 			if (count < 0)
 				fatal("Cannot read symlink %s\n", de->d_name);
@@ -1245,71 +1316,21 @@ static void read_slab_dir(void)
 			alias->ref = strdup(p);
 			alias++;
 			break;
-		   case DT_DIR:
+		case DT_DIR:
 			if (slab - slabinfo == MAX_SLABS)
 				fatal("Too many slabs\n");
 			if (chdir(de->d_name))
 				fatal("Unable to access slab %s\n", slab->name);
-			slab->name = strdup(de->d_name);
-			slab->alias = 0;
-			slab->refs = 0;
-			slab->aliases = get_obj("aliases");
-			slab->align = get_obj("align");
-			slab->cache_dma = get_obj("cache_dma");
-			slab->cpu_slabs = get_obj("cpu_slabs");
-			slab->destroy_by_rcu = get_obj("destroy_by_rcu");
-			slab->hwcache_align = get_obj("hwcache_align");
-			slab->object_size = get_obj("object_size");
-			slab->objects = get_obj("objects");
-			slab->objects_partial = get_obj("objects_partial");
-			slab->total_objects = get_obj("total_objects");
-			slab->objs_per_slab = get_obj("objs_per_slab");
-			slab->order = get_obj("order");
-			slab->partial = get_obj_and_str("partial", &t);
-			decode_numa_list(slab->numa_partial, t);
-			free(t);
-			slab->poison = get_obj("poison");
-			slab->reclaim_account = get_obj("reclaim_account");
-			slab->red_zone = get_obj("red_zone");
-			slab->sanity_checks = get_obj("sanity_checks");
-			slab->slab_size = get_obj("slab_size");
-			slab->slabs = get_obj_and_str("slabs", &t);
-			decode_numa_list(slab->numa, t);
-			free(t);
-			slab->store_user = get_obj("store_user");
-			slab->trace = get_obj("trace");
-			slab->alloc_fastpath = get_obj("alloc_fastpath");
-			slab->alloc_slowpath = get_obj("alloc_slowpath");
-			slab->free_fastpath = get_obj("free_fastpath");
-			slab->free_slowpath = get_obj("free_slowpath");
-			slab->free_frozen= get_obj("free_frozen");
-			slab->free_add_partial = get_obj("free_add_partial");
-			slab->free_remove_partial = get_obj("free_remove_partial");
-			slab->alloc_from_partial = get_obj("alloc_from_partial");
-			slab->alloc_slab = get_obj("alloc_slab");
-			slab->alloc_refill = get_obj("alloc_refill");
-			slab->free_slab = get_obj("free_slab");
-			slab->cpuslab_flush = get_obj("cpuslab_flush");
-			slab->deactivate_full = get_obj("deactivate_full");
-			slab->deactivate_empty = get_obj("deactivate_empty");
-			slab->deactivate_to_head = get_obj("deactivate_to_head");
-			slab->deactivate_to_tail = get_obj("deactivate_to_tail");
-			slab->deactivate_remote_frees = get_obj("deactivate_remote_frees");
-			slab->order_fallback = get_obj("order_fallback");
-			slab->cmpxchg_double_cpu_fail = get_obj("cmpxchg_double_cpu_fail");
-			slab->cmpxchg_double_fail = get_obj("cmpxchg_double_fail");
-			slab->cpu_partial_alloc = get_obj("cpu_partial_alloc");
-			slab->cpu_partial_free = get_obj("cpu_partial_free");
-			slab->alloc_node_mismatch = get_obj("alloc_node_mismatch");
-			slab->deactivate_bypass = get_obj("deactivate_bypass");
+
+			fill_slabinfo(slab, de->d_name);
+
 			if (chdir(".."))
-				fatal("Unable to chdir from slab ../%s\n",
-				      slab->name);
+				fatal("Unable to chdir from slab ../%s\n", slab->name);
 			if (slab->name[0] == ':')
 				alias_targets++;
 			slab++;
 			break;
-		   default :
+		default:
 			fatal("Unknown file type %lx\n", de->d_type);
 		}
 	}
@@ -1324,12 +1345,7 @@ static void output_slabs(void)
 	struct slabinfo *slab;
 	int lines = output_lines;
 
-	for (slab = slabinfo; (slab < slabinfo + slabs) &&
-			lines != 0; slab++) {
-
-		if (slab->alias)
-			continue;
-
+	for (slab = slabinfo; (slab < slabinfo + slabs) && lines != 0; slab++) {
 		if (lines != -1)
 			lines--;
 
@@ -1528,9 +1544,10 @@ int main(int argc, char *argv[])
 
 	err = regcomp(&pattern, pattern_source, REG_ICASE|REG_NOSUB);
 	if (err)
-		fatal("%s: Invalid pattern '%s' code %d\n",
-			argv[0], pattern_source, err);
+		fatal("%s: Invalid pattern '%s' code %d\n", argv[0], pattern_source, err);
+
 	read_slab_dir();
+
 	if (show_alias) {
 		alias();
 	} else if (extended_totals) {

-- 
2.43.0

[PATCH 2/2] tools/mm/slabinfo: report percpu sheaves and barn statistics

[Seongjun Hong]

Since commit 2d517aa09bbc ("slab: add opt-in caching layer of percpu
sheaves") sysfs provides the statistics of sheaf and barn, but slabinfo
did not utilize this information. Display perf, API, and sheaf allocation
counters on slabinfo report(-r).

Example slabinfo report output:

	$ slabinfo -r kmalloc-1k

	Sheaf capacity             12 objects

	Sheaf Perf Counter    Success     Fail
	--------------------------------------------------
	Barn get                    4       43
	Barn put                    4        0
	RCU sheaf free             34        0

	Sheaf API Counter        Fast     Slow
	--------------------------------------------------
	Prefill                     0        0
	Return                      0        0

	Sheaf Objects/Allocations
	--------------------------------------------------
	Objects flushed to slabs             0
	Objects refilled into sheaves      516
	Sheaves allocated                    7
	Sheaves freed                        0
	Oversize sheaves for prefill         0

Signed-off-by: Seongjun Hong <hsj0512@snu.ac.kr>
---
 tools/mm/slabinfo.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)

diff --git a/tools/mm/slabinfo.c b/tools/mm/slabinfo.c
index 84359d628f2e..dbc72582ffab 100644
--- a/tools/mm/slabinfo.c
+++ b/tools/mm/slabinfo.c
@@ -33,6 +33,7 @@ struct slabinfo {
 
 	unsigned int slab_size, object_size;
 	unsigned int objs_per_slab, order;
+	unsigned int sheaf_capacity;
 	unsigned long objects_partial, partial;
 	int aliases;
 	unsigned int align;
@@ -49,12 +50,19 @@ struct slabinfo {
 
 	/* CONFIG_SLUB_STATS */
 	unsigned long alloc_fastpath, alloc_slowpath;
+	unsigned long free_rcu_sheaf, free_rcu_sheaf_fail;
 	unsigned long free_fastpath, free_slowpath;
 	unsigned long free_add_partial, free_remove_partial;
 	unsigned long alloc_slab, alloc_node_mismatch, free_slab;
 	unsigned long order_fallback;
 	unsigned long cmpxchg_double_fail;
 
+	unsigned long sheaf_flush, sheaf_refill, sheaf_alloc, sheaf_free;
+	unsigned long barn_get, barn_get_fail, barn_put, barn_put_fail;
+	unsigned long sheaf_prefill_fast, sheaf_prefill_slow,
+		sheaf_prefill_oversize;
+	unsigned long sheaf_return_fast, sheaf_return_slow;
+
 	/*
 	 * Deprecated files:
 	 * No STAT_ATTR()/SLAB_ATTR() for these exists in mm/slub.c's
@@ -574,6 +582,39 @@ static void slab_stats(struct slabinfo *s)
 	}
 }
 
+static void sheaf_stats(struct slabinfo *s)
+{
+	if (!s->sheaf_capacity)
+		return;
+
+	printf("\nSheaf capacity       %8u objects\n", s->sheaf_capacity);
+
+	printf("\nSheaf Perf Counter    Success     Fail\n");
+	printf("--------------------------------------------------\n");
+	printf("Barn get             %8lu %8lu\n",
+		s->barn_get, s->barn_get_fail);
+	printf("Barn put             %8lu %8lu\n",
+		s->barn_put, s->barn_put_fail);
+	printf("RCU sheaf free       %8lu %8lu\n",
+		s->free_rcu_sheaf, s->free_rcu_sheaf_fail);
+
+	printf("\nSheaf API Counter        Fast     Slow\n");
+	printf("--------------------------------------------------\n");
+	printf("Prefill              %8lu %8lu\n",
+		s->sheaf_prefill_fast, s->sheaf_prefill_slow);
+	printf("Return               %8lu %8lu\n",
+		s->sheaf_return_fast, s->sheaf_return_slow);
+
+	printf("\nSheaf Objects/Allocations\n");
+	printf("--------------------------------------------------\n");
+	printf("Objects flushed to slabs      %8lu\n", s->sheaf_flush);
+	printf("Objects refilled into sheaves %8lu\n", s->sheaf_refill);
+	printf("Sheaves allocated             %8lu\n", s->sheaf_alloc);
+	printf("Sheaves freed                 %8lu\n", s->sheaf_free);
+	printf("Oversize sheaves for prefill  %8lu\n",
+		s->sheaf_prefill_oversize);
+}
+
 static void report(struct slabinfo *s)
 {
 	if (strcmp(s->name, "*") == 0)
@@ -613,6 +654,7 @@ static void report(struct slabinfo *s)
 	show_tracking(s);
 	slab_numa(s, 1);
 	slab_stats(s);
+	sheaf_stats(s);
 }
 
 static void slabcache(struct slabinfo *s)
@@ -1280,6 +1322,22 @@ static void fill_slabinfo(struct slabinfo *slab, const char *name)
 	slab->cpu_partial_free = get_obj("cpu_partial_free");
 	slab->alloc_node_mismatch = get_obj("alloc_node_mismatch");
 	slab->deactivate_bypass = get_obj("deactivate_bypass");
+	slab->sheaf_capacity = get_obj("sheaf_capacity");
+	slab->free_rcu_sheaf = get_obj("free_rcu_sheaf");
+	slab->free_rcu_sheaf_fail = get_obj("free_rcu_sheaf_fail");
+	slab->sheaf_flush = get_obj("sheaf_flush");
+	slab->sheaf_refill = get_obj("sheaf_refill");
+	slab->sheaf_alloc = get_obj("sheaf_alloc");
+	slab->sheaf_free = get_obj("sheaf_free");
+	slab->barn_get = get_obj("barn_get");
+	slab->barn_get_fail = get_obj("barn_get_fail");
+	slab->barn_put = get_obj("barn_put");
+	slab->barn_put_fail = get_obj("barn_put_fail");
+	slab->sheaf_prefill_fast = get_obj("sheaf_prefill_fast");
+	slab->sheaf_prefill_slow = get_obj("sheaf_prefill_slow");
+	slab->sheaf_prefill_oversize = get_obj("sheaf_prefill_oversize");
+	slab->sheaf_return_fast = get_obj("sheaf_return_fast");
+	slab->sheaf_return_slow = get_obj("sheaf_return_slow");
 }
 
 static void read_slab_dir(void)

-- 
2.43.0

Re: [PATCH 1/2] tools/mm/slabinfo: refactor slab attribute reading

[Harry Yoo]

Hi Seongjun, thanks for working on tools/mm/slabinfo improvements!
My comments inlined below.

On Sun, Sep 27, 2026 at 05:57:27AM +0000, Seongjun Hong wrote:
> The fields of struct slabinfo were mixed with deprecated sysfs files,
> which looks complicated. Organize every field of struct slabinfo by
> config option and the attribute order in mm/slub.c's slab_attrs[]. Because
> slabinfo should be able to run on previous kernel releases, leave the
> deprecated members for this time.
>
> read_slab_dir() had ~50 lines of attribute reads inlined. Move them to a
> new fill_slabinfo() helper so that directory walk and per-cache
> attribute reading are separated.
> 
> Fold get_obj_and_str() and decode_numa_list() into get_obj_and_decode()
> to avoid unnecessary strdup() and leave only one member assignment in
> fill_slabinfo() for each sysfs file.
> 
> Make broken statements into a single line for better readibility.
> 
> Remove alias field from struct slabinfo because it is initialized to 0
> and never updated. The only usage of this field "if (slab->alias)" is dead.

Would you please separate this patch into multiple patches?
It's hard to review when multiple refactorings are done in a single
patch.

> No functional change intended.
> 
> Signed-off-by: Seongjun Hong <hsj0512@snu.ac.kr>
> ---
>
>  tools/mm/slabinfo.c | 245 ++++++++++++++++++++++++++++------------------------
>  1 file changed, 131 insertions(+), 114 deletions(-)
> 
> diff --git a/tools/mm/slabinfo.c b/tools/mm/slabinfo.c
> index 48d1ee8b0e81..84359d628f2e 100644
> --- a/tools/mm/slabinfo.c
> +++ b/tools/mm/slabinfo.c
> @@ -27,25 +27,49 @@
>  
>  struct slabinfo {
>  	char *name;
> -	int alias;
>  	int refs;
> -	int aliases, align, cache_dma, cpu_slabs, destroy_by_rcu;
> -	unsigned int hwcache_align, object_size, objs_per_slab;
> -	unsigned int sanity_checks, slab_size, store_user, trace;
> -	int order, poison, reclaim_account, red_zone;
> -	unsigned long partial, objects, slabs, objects_partial, total_objects;
> +	int numa_slabs[MAX_NODES];
> +	int numa_partial[MAX_NODES];
> +
> +	unsigned int slab_size, object_size;
> +	unsigned int objs_per_slab, order;
> +	unsigned long objects_partial, partial;
> +	int aliases;
> +	unsigned int align;
> +	int hwcache_align;
> +	int reclaim_account;
> +	int destroy_by_rcu;
> +
> +	/* CONFIG_SLUB_DEBUG */
> +	unsigned long total_objects, objects, slabs;
> +	int sanity_checks, trace, red_zone, poison, store_user;
> +
> +	/* CONFIG_ZONE_DMA */
> +	int cache_dma;
> +
> +	/* CONFIG_SLUB_STATS */
>  	unsigned long alloc_fastpath, alloc_slowpath;
>  	unsigned long free_fastpath, free_slowpath;
> -	unsigned long free_frozen, free_add_partial, free_remove_partial;
> -	unsigned long alloc_from_partial, alloc_slab, free_slab, alloc_refill;
> -	unsigned long cpuslab_flush, deactivate_full, deactivate_empty;
> +	unsigned long free_add_partial, free_remove_partial;
> +	unsigned long alloc_slab, alloc_node_mismatch, free_slab;
> +	unsigned long order_fallback;
> +	unsigned long cmpxchg_double_fail;
> +
> +	/*
> +	 * Deprecated files:
> +	 * No STAT_ATTR()/SLAB_ATTR() for these exists in mm/slub.c's
> +	 * slab_attrs[] anymore.

This part of the comment looks fine, but

> Although cpu_slabs remains as a file,
> +	 * it is also outdated and always prints 0. Keep these for backward
> +	 * compatibility, but they should be removed later.

This doesn't seem useful information to put in the comment.

We were able to remove some files when
Documentation/ABI/testing/sysfs-kernel-slab says
"Available when CONFIG_SLUB_STATS is enabled", because that implies that
those files may not exist. 

But it's not the case for files like cpu_slabs,
and I don't think we're going to remove them in the future.

Probably simply say something like

"Deprecated files: the kernel does not create those files anymore or
 always prints hardecoded "0" since they are deprecated" ?

> +	 */
> +	int cpu_slabs;
> +	unsigned long free_frozen;
>  	unsigned long deactivate_to_head, deactivate_to_tail;
> -	unsigned long deactivate_remote_frees, order_fallback;
> -	unsigned long cmpxchg_double_cpu_fail, cmpxchg_double_fail;
> -	unsigned long alloc_node_mismatch, deactivate_bypass;
> +	unsigned long alloc_from_partial, alloc_refill;
> +	unsigned long cpuslab_flush, deactivate_full, deactivate_empty;
> +	unsigned long deactivate_remote_frees, deactivate_bypass;
> +	unsigned long cmpxchg_double_cpu_fail;
>  	unsigned long cpu_partial_alloc, cpu_partial_free;
> -	int numa[MAX_NODES];
> -	int numa_partial[MAX_NODES];
>  } slabinfo[MAX_SLABS];

-- 
Cheers,
Harry / Hyeonggon

Re: [PATCH 2/2] tools/mm/slabinfo: report percpu sheaves and barn statistics

[Harry Yoo]

On Sun, Sep 27, 2026 at 05:57:28AM +0000, Seongjun Hong wrote:
> Since commit 2d517aa09bbc ("slab: add opt-in caching layer of percpu
> sheaves") sysfs provides the statistics of sheaf and barn, but slabinfo
> did not utilize this information. Display perf, API, and sheaf allocation
> counters on slabinfo report(-r).
> 
> Example slabinfo report output:
> 
> 	$ slabinfo -r kmalloc-1k
> 
> 	Sheaf capacity             12 objects
> 
> 	Sheaf Perf Counter    Success     Fail
> 	--------------------------------------------------
> 	Barn get                    4       43
> 	Barn put                    4        0
> 	RCU sheaf free             34        0
> 
> 	Sheaf API Counter        Fast     Slow
> 	--------------------------------------------------
> 	Prefill                     0        0
> 	Return                      0        0

You mean "Prefilled Sheaf API Counter"?

> 	Sheaf Objects/Allocations

This doesn't make sense to me.

Perhaps should be separated into
"Sheaf Allocation/Free" and
"Sheaf Refill/Flush" ?


> 	--------------------------------------------------
> 	Objects flushed to slabs             0
> 	Objects refilled into sheaves      516
> 	Sheaves allocated                    7
> 	Sheaves freed                        0
> 	Oversize sheaves for prefill         0
> 
> Signed-off-by: Seongjun Hong <hsj0512@snu.ac.kr>
> ---
>  tools/mm/slabinfo.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 58 insertions(+)
> 
> diff --git a/tools/mm/slabinfo.c b/tools/mm/slabinfo.c
> index 84359d628f2e..dbc72582ffab 100644
> --- a/tools/mm/slabinfo.c
> +++ b/tools/mm/slabinfo.c
> @@ -574,6 +582,39 @@ static void slab_stats(struct slabinfo *s)
>  	}
>  }
>  
> +static void sheaf_stats(struct slabinfo *s)

Perhaps let's fold this into slab_stats()?
I'm not sure why this should be in a separate function.
These files are part of SLUB_STATS files, that are related to sheaves.

-- 
Cheers,
Harry / Hyeonggon

> +{
> +	if (!s->sheaf_capacity)
> +		return;
> +
> +	printf("\nSheaf capacity       %8u objects\n", s->sheaf_capacity);
> +
> +	printf("\nSheaf Perf Counter    Success     Fail\n");
> +	printf("--------------------------------------------------\n");
> +	printf("Barn get             %8lu %8lu\n",
> +		s->barn_get, s->barn_get_fail);
> +	printf("Barn put             %8lu %8lu\n",
> +		s->barn_put, s->barn_put_fail);
> +	printf("RCU sheaf free       %8lu %8lu\n",
> +		s->free_rcu_sheaf, s->free_rcu_sheaf_fail);
> +
> +	printf("\nSheaf API Counter        Fast     Slow\n");
> +	printf("--------------------------------------------------\n");
> +	printf("Prefill              %8lu %8lu\n",
> +		s->sheaf_prefill_fast, s->sheaf_prefill_slow);
> +	printf("Return               %8lu %8lu\n",
> +		s->sheaf_return_fast, s->sheaf_return_slow);
> +
> +	printf("\nSheaf Objects/Allocations\n");
> +	printf("--------------------------------------------------\n");
> +	printf("Objects flushed to slabs      %8lu\n", s->sheaf_flush);
> +	printf("Objects refilled into sheaves %8lu\n", s->sheaf_refill);
> +	printf("Sheaves allocated             %8lu\n", s->sheaf_alloc);
> +	printf("Sheaves freed                 %8lu\n", s->sheaf_free);
> +	printf("Oversize sheaves for prefill  %8lu\n",
> +		s->sheaf_prefill_oversize);
> +}
> +
>  static void report(struct slabinfo *s)
>  {
>  	if (strcmp(s->name, "*") == 0)
> @@ -613,6 +654,7 @@ static void report(struct slabinfo *s)
>  	show_tracking(s);
>  	slab_numa(s, 1);
>  	slab_stats(s);
> +	sheaf_stats(s);
>  }