Merge branch 'slub-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/christoph/vm

* 'slub-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/christoph/vm:
  SLUB: fix checkpatch warnings
  Use non atomic unlock
  SLUB: Support for performance statistics
  SLUB: Alternate fast paths using cmpxchg_local
  SLUB: Use unique end pointer for each slab page.
  SLUB: Deal with annoying gcc warning on kfree()

Documentation/vm/slabinfo.c

@@ -32,6 +32,13 @@ struct slabinfo {
 	int sanity_checks, slab_size, store_user, trace;
 	int order, poison, reclaim_account, red_zone;
 	unsigned long partial, objects, slabs;
+	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 deactivate_to_head, deactivate_to_tail;
+	unsigned long deactivate_remote_frees;
 	int numa[MAX_NODES];
 	int numa_partial[MAX_NODES];
 } slabinfo[MAX_SLABS];
@@ -64,8 +71,10 @@ int show_inverted = 0;
 int show_single_ref = 0;
 int show_totals = 0;
 int sort_size = 0;
+int sort_active = 0;
 int set_debug = 0;
 int show_ops = 0;
+int show_activity = 0;
 
 /* Debug options */
 int sanity = 0;
@@ -93,7 +102,9 @@ void usage(void)
 	printf("slabinfo 5/7/2007. (c) 2007 sgi. clameter@sgi.com\n\n"
 		"slabinfo [-ahnpvtsz] [-d debugopts] [slab-regexp]\n"
 		"-a|--aliases           Show aliases\n"
+		"-A|--activity          Most active slabs first\n"
 		"-d<options>|--debug=<options> Set/Clear Debug options\n"
+		"-D|--display-active    Switch line format to activity\n"
 		"-e|--empty             Show empty slabs\n"
 		"-f|--first-alias       Show first alias\n"
 		"-h|--help              Show usage information\n"
@@ -281,6 +292,9 @@ int line = 0;
 
 void first_line(void)
 {
+	if (show_activity)
+		printf("Name                   Objects    Alloc     Free   %%Fast\n");
+	else
 		printf("Name                   Objects Objsize    Space "
 			"Slabs/Part/Cpu  O/S O %%Fr %%Ef Flg\n");
 }
@@ -309,6 +323,12 @@ unsigned long slab_size(struct slabinfo *s)
 	return 	s->slabs * (page_size << s->order);
 }
 
+unsigned long slab_activity(struct slabinfo *s)
+{
+	return 	s->alloc_fastpath + s->free_fastpath +
+		s->alloc_slowpath + s->free_slowpath;
+}
+
 void slab_numa(struct slabinfo *s, int mode)
 {
 	int node;
@@ -392,6 +412,71 @@ const char *onoff(int x)
 	return "Off";
 }
 
+void slab_stats(struct slabinfo *s)
+{
+	unsigned long total_alloc;
+	unsigned long total_free;
+	unsigned long total;
+
+	if (!s->alloc_slab)
+		return;
+
+	total_alloc = s->alloc_fastpath + s->alloc_slowpath;
+	total_free = s->free_fastpath + s->free_slowpath;
+
+	if (!total_alloc)
+		return;
+
+	printf("\n");
+	printf("Slab Perf Counter       Alloc     Free %%Al %%Fr\n");
+	printf("--------------------------------------------------\n");
+	printf("Fastpath             %8lu %8lu %3lu %3lu\n",
+		s->alloc_fastpath, s->free_fastpath,
+		s->alloc_fastpath * 100 / total_alloc,
+		s->free_fastpath * 100 / total_free);
+	printf("Slowpath             %8lu %8lu %3lu %3lu\n",
+		total_alloc - s->alloc_fastpath, s->free_slowpath,
+		(total_alloc - s->alloc_fastpath) * 100 / total_alloc,
+		s->free_slowpath * 100 / total_free);
+	printf("Page Alloc           %8lu %8lu %3lu %3lu\n",
+		s->alloc_slab, s->free_slab,
+		s->alloc_slab * 100 / total_alloc,
+		s->free_slab * 100 / total_free);
+	printf("Add partial          %8lu %8lu %3lu %3lu\n",
+		s->deactivate_to_head + s->deactivate_to_tail,
+		s->free_add_partial,
+		(s->deactivate_to_head + s->deactivate_to_tail) * 100 / total_alloc,
+		s->free_add_partial * 100 / total_free);
+	printf("Remove partial       %8lu %8lu %3lu %3lu\n",
+		s->alloc_from_partial, s->free_remove_partial,
+		s->alloc_from_partial * 100 / total_alloc,
+		s->free_remove_partial * 100 / total_free);
+
+	printf("RemoteObj/SlabFrozen %8lu %8lu %3lu %3lu\n",
+		s->deactivate_remote_frees, s->free_frozen,
+		s->deactivate_remote_frees * 100 / total_alloc,
+		s->free_frozen * 100 / total_free);
+
+	printf("Total                %8lu %8lu\n\n", total_alloc, total_free);
+
+	if (s->cpuslab_flush)
+		printf("Flushes %8lu\n", s->cpuslab_flush);
+
+	if (s->alloc_refill)
+		printf("Refill %8lu\n", s->alloc_refill);
+
+	total = s->deactivate_full + s->deactivate_empty +
+			s->deactivate_to_head + s->deactivate_to_tail;
+
+	if (total)
+		printf("Deactivate Full=%lu(%lu%%) Empty=%lu(%lu%%) "
+			"ToHead=%lu(%lu%%) ToTail=%lu(%lu%%)\n",
+			s->deactivate_full, (s->deactivate_full * 100) / total,
+			s->deactivate_empty, (s->deactivate_empty * 100) / total,
+			s->deactivate_to_head, (s->deactivate_to_head * 100) / total,
+			s->deactivate_to_tail, (s->deactivate_to_tail * 100) / total);
+}
+
 void report(struct slabinfo *s)
 {
 	if (strcmp(s->name, "*") == 0)
@@ -430,6 +515,7 @@ void report(struct slabinfo *s)
 	ops(s);
 	show_tracking(s);
 	slab_numa(s, 1);
+	slab_stats(s);
 }
 
 void slabcache(struct slabinfo *s)
@@ -479,6 +565,20 @@ void slabcache(struct slabinfo *s)
 		*p++ = 'T';
 
 	*p = 0;
+	if (show_activity) {
+		unsigned long total_alloc;
+		unsigned long total_free;
+
+		total_alloc = s->alloc_fastpath + s->alloc_slowpath;
+		total_free = s->free_fastpath + s->free_slowpath;
+
+		printf("%-21s %8ld %8ld %8ld %3ld %3ld \n",
+			s->name, s->objects,
+			total_alloc, total_free,
+			total_alloc ? (s->alloc_fastpath * 100 / total_alloc) : 0,
+			total_free ? (s->free_fastpath * 100 / total_free) : 0);
+	}
+	else
 		printf("%-21s %8ld %7d %8s %14s %4d %1d %3ld %3ld %s\n",
 			s->name, s->objects, s->object_size, size_str, dist_str,
 			s->objs_per_slab, s->order,
@@ -892,6 +992,8 @@ void sort_slabs(void)
 
 			if (sort_size)
 				result = slab_size(s1) < slab_size(s2);
+			else if (sort_active)
+				result = slab_activity(s1) < slab_activity(s2);
 			else
 				result = strcasecmp(s1->name, s2->name);
 
@@ -1074,6 +1176,23 @@ void read_slab_dir(void)
 			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");
 			chdir("..");
 			if (slab->name[0] == ':')
 				alias_targets++;
@@ -1124,7 +1243,9 @@ void output_slabs(void)
 
 struct option opts[] = {
 	{ "aliases", 0, NULL, 'a' },
+	{ "activity", 0, NULL, 'A' },
 	{ "debug", 2, NULL, 'd' },
+	{ "display-activity", 0, NULL, 'D' },
 	{ "empty", 0, NULL, 'e' },
 	{ "first-alias", 0, NULL, 'f' },
 	{ "help", 0, NULL, 'h' },
@@ -1149,7 +1270,7 @@ int main(int argc, char *argv[])
 
 	page_size = getpagesize();
 
-	while ((c = getopt_long(argc, argv, "ad::efhil1noprstvzTS",
+	while ((c = getopt_long(argc, argv, "aAd::Defhil1noprstvzTS",
 						opts, NULL)) != -1)
 		switch (c) {
 		case '1':
@@ -1158,11 +1279,17 @@ int main(int argc, char *argv[])
 		case 'a':
 			show_alias = 1;
 			break;
+		case 'A':
+			sort_active = 1;
+			break;
 		case 'd':
 			set_debug = 1;
 			if (!debug_opt_scan(optarg))
 				fatal("Invalid debug option '%s'\n", optarg);
 			break;
+		case 'D':
+			show_activity = 1;
+			break;
 		case 'e':
 			show_empty = 1;
 			break;

arch/x86/Kconfig

@@ -52,6 +52,10 @@ config HAVE_LATENCYTOP_SUPPORT
 config SEMAPHORE_SLEEPERS
 	def_bool y
 
+config FAST_CMPXCHG_LOCAL
+	bool
+	default y
+
 config MMU
 	def_bool y
 

include/linux/mm_types.h

@@ -64,7 +64,10 @@ struct page {
 #if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
 	    spinlock_t ptl;
 #endif
+	    struct {
 		   struct kmem_cache *slab;	/* SLUB: Pointer to slab */
+		   void *end;			/* SLUB: end marker */
+	    };
 	    struct page *first_page;	/* Compound tail pages */
 	};
 	union {

include/linux/slub_def.h

@@ -11,12 +11,35 @@
 #include <linux/workqueue.h>
 #include <linux/kobject.h>
 
+enum stat_item {
+	ALLOC_FASTPATH,		/* Allocation from cpu slab */
+	ALLOC_SLOWPATH,		/* Allocation by getting a new cpu slab */
+	FREE_FASTPATH,		/* Free to cpu slub */
+	FREE_SLOWPATH,		/* Freeing not to cpu slab */
+	FREE_FROZEN,		/* Freeing to frozen slab */
+	FREE_ADD_PARTIAL,	/* Freeing moves slab to partial list */
+	FREE_REMOVE_PARTIAL,	/* Freeing removes last object */
+	ALLOC_FROM_PARTIAL,	/* Cpu slab acquired from partial list */
+	ALLOC_SLAB,		/* Cpu slab acquired from page allocator */
+	ALLOC_REFILL,		/* Refill cpu slab from slab freelist */
+	FREE_SLAB,		/* Slab freed to the page allocator */
+	CPUSLAB_FLUSH,		/* Abandoning of the cpu slab */
+	DEACTIVATE_FULL,	/* Cpu slab was full when deactivated */
+	DEACTIVATE_EMPTY,	/* Cpu slab was empty when deactivated */
+	DEACTIVATE_TO_HEAD,	/* Cpu slab was moved to the head of partials */
+	DEACTIVATE_TO_TAIL,	/* Cpu slab was moved to the tail of partials */
+	DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
+	NR_SLUB_STAT_ITEMS };
+
 struct kmem_cache_cpu {
 	void **freelist;	/* Pointer to first free per cpu object */
 	struct page *page;	/* The slab from which we are allocating */
 	int node;		/* The node of the page (or -1 for debug) */
 	unsigned int offset;	/* Freepointer offset (in word units) */
 	unsigned int objsize;	/* Size of an object (from kmem_cache) */
+#ifdef CONFIG_SLUB_STATS
+	unsigned stat[NR_SLUB_STAT_ITEMS];
+#endif
 };
 
 struct kmem_cache_node {

lib/Kconfig.debug

@@ -205,6 +205,19 @@ config SLUB_DEBUG_ON
 	  off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
 	  "slub_debug=-".
 
+config SLUB_STATS
+	default n
+	bool "Enable SLUB performance statistics"
+	depends on SLUB
+	help
+	  SLUB statistics are useful to debug SLUBs allocation behavior in
+	  order find ways to optimize the allocator. This should never be
+	  enabled for production use since keeping statistics slows down
+	  the allocator by a few percentage points. The slabinfo command
+	  supports the determination of the most active slabs to figure
+	  out which slabs are relevant to a particular load.
+	  Try running: slabinfo -DA
+
 config DEBUG_PREEMPT
 	bool "Debug preemptible kernel"
 	depends on DEBUG_KERNEL && PREEMPT && (TRACE_IRQFLAGS_SUPPORT || PPC64)