diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt
index 7cee90223d3a0624296b42d983d786b25462dc56..20d0d797f539ce51d18f903aa4aec942ead16643 100644
--- a/Documentation/sysctl/vm.txt
+++ b/Documentation/sysctl/vm.txt
@@ -29,6 +29,7 @@ Currently, these files are in /proc/sys/vm:
- drop-caches
- zone_reclaim_mode
- min_unmapped_ratio
+- min_slab_ratio
- panic_on_oom
==============================================================
@@ -138,7 +139,6 @@ This is value ORed together of
1 = Zone reclaim on
2 = Zone reclaim writes dirty pages out
4 = Zone reclaim swaps pages
-8 = Also do a global slab reclaim pass
zone_reclaim_mode is set during bootup to 1 if it is determined that pages
from remote zones will cause a measurable performance reduction. The
@@ -162,18 +162,13 @@ Allowing regular swap effectively restricts allocations to the local
node unless explicitly overridden by memory policies or cpuset
configurations.
-It may be advisable to allow slab reclaim if the system makes heavy
-use of files and builds up large slab caches. However, the slab
-shrink operation is global, may take a long time and free slabs
-in all nodes of the system.
-
=============================================================
min_unmapped_ratio:
This is available only on NUMA kernels.
-A percentage of the file backed pages in each zone. Zone reclaim will only
+A percentage of the total pages in each zone. Zone reclaim will only
occur if more than this percentage of pages are file backed and unmapped.
This is to insure that a minimal amount of local pages is still available for
file I/O even if the node is overallocated.
@@ -182,6 +177,24 @@ The default is 1 percent.
=============================================================
+min_slab_ratio:
+
+This is available only on NUMA kernels.
+
+A percentage of the total pages in each zone. On Zone reclaim
+(fallback from the local zone occurs) slabs will be reclaimed if more
+than this percentage of pages in a zone are reclaimable slab pages.
+This insures that the slab growth stays under control even in NUMA
+systems that rarely perform global reclaim.
+
+The default is 5 percent.
+
+Note that slab reclaim is triggered in a per zone / node fashion.
+The process of reclaiming slab memory is currently not node specific
+and may not be fast.
+
+=============================================================
+
panic_on_oom
This enables or disables panic on out-of-memory feature. If this is set to 1,
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 08c41b9f92e0e8dc54621e1838be20564cd3c7ab..3693f1a5278839c23243691564a5085af0617313 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -171,6 +171,7 @@ struct zone {
* zone reclaim becomes active if more unmapped pages exist.
*/
unsigned long min_unmapped_pages;
+ unsigned long min_slab_pages;
struct per_cpu_pageset *pageset[NR_CPUS];
#else
struct per_cpu_pageset pageset[NR_CPUS];
@@ -448,6 +449,8 @@ int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, struct file
void __user *, size_t *, loff_t *);
int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,
struct file *, void __user *, size_t *, loff_t *);
+int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int,
+ struct file *, void __user *, size_t *, loff_t *);
#include <linux/topology.h>
/* Returns the number of the current Node. */
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 32db06c8ffe0801fe894afc10c9a8ba0200faee3..a2f5ad7c2d2e2ec700dd3d8b4e7dfac57f9e1136 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -193,6 +193,7 @@ extern long vm_total_pages;
#ifdef CONFIG_NUMA
extern int zone_reclaim_mode;
extern int sysctl_min_unmapped_ratio;
+extern int sysctl_min_slab_ratio;
extern int zone_reclaim(struct zone *, gfp_t, unsigned int);
#else
#define zone_reclaim_mode 0
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 736ed917a4f8df2af5d25e1e8cc567cada1d863d..eca555781d05e1d67e62d070202ced6ac6bcfb84 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -191,6 +191,7 @@ enum
VM_MIN_UNMAPPED=32, /* Set min percent of unmapped pages */
VM_PANIC_ON_OOM=33, /* panic at out-of-memory */
VM_VDSO_ENABLED=34, /* map VDSO into new processes? */
+ VM_MIN_SLAB=35, /* Percent pages ignored by zone reclaim */
};
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 362a0cc371381cceab3f4a77b03430a604ecdb71..fd43c3e6786b5b19c8ff173b45638c56392c7d86 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -943,6 +943,17 @@ static ctl_table vm_table[] = {
.extra1 = &zero,
.extra2 = &one_hundred,
},
+ {
+ .ctl_name = VM_MIN_SLAB,
+ .procname = "min_slab_ratio",
+ .data = &sysctl_min_slab_ratio,
+ .maxlen = sizeof(sysctl_min_slab_ratio),
+ .mode = 0644,
+ .proc_handler = &sysctl_min_slab_ratio_sysctl_handler,
+ .strategy = &sysctl_intvec,
+ .extra1 = &zero,
+ .extra2 = &one_hundred,
+ },
#endif
#ifdef CONFIG_X86_32
{
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 47e98423b30dd6da8dea3e1bf03e8d7e3bf85cf0..cf913bdd433e29b3b371bd97383f2c3c152248ce 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2005,6 +2005,7 @@ static void __meminit free_area_init_core(struct pglist_data *pgdat,
#ifdef CONFIG_NUMA
zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
/ 100;
+ zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
#endif
zone->name = zone_names[j];
spin_lock_init(&zone->lock);
@@ -2318,6 +2319,22 @@ int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
sysctl_min_unmapped_ratio) / 100;
return 0;
}
+
+int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
+ struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
+{
+ struct zone *zone;
+ int rc;
+
+ rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
+ if (rc)
+ return rc;
+
+ for_each_zone(zone)
+ zone->min_slab_pages = (zone->present_pages *
+ sysctl_min_slab_ratio) / 100;
+ return 0;
+}
#endif
/*
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 349797ba4bac37fa476c5f33af8212afd33f3b3b..089e943c4d38f56c75309386dde288ab35eed7e8 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1527,7 +1527,6 @@ int zone_reclaim_mode __read_mostly;
#define RECLAIM_ZONE (1<<0) /* Run shrink_cache on the zone */
#define RECLAIM_WRITE (1<<1) /* Writeout pages during reclaim */
#define RECLAIM_SWAP (1<<2) /* Swap pages out during reclaim */
-#define RECLAIM_SLAB (1<<3) /* Do a global slab shrink if the zone is out of memory */
/*
* Priority for ZONE_RECLAIM. This determines the fraction of pages
@@ -1542,6 +1541,12 @@ int zone_reclaim_mode __read_mostly;
*/
int sysctl_min_unmapped_ratio = 1;
+/*
+ * If the number of slab pages in a zone grows beyond this percentage then
+ * slab reclaim needs to occur.
+ */
+int sysctl_min_slab_ratio = 5;
+
/*
* Try to free up some pages from this zone through reclaim.
*/
@@ -1573,29 +1578,37 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
reclaim_state.reclaimed_slab = 0;
p->reclaim_state = &reclaim_state;
- /*
- * Free memory by calling shrink zone with increasing priorities
- * until we have enough memory freed.
- */
- priority = ZONE_RECLAIM_PRIORITY;
- do {
- nr_reclaimed += shrink_zone(priority, zone, &sc);
- priority--;
- } while (priority >= 0 && nr_reclaimed < nr_pages);
+ if (zone_page_state(zone, NR_FILE_PAGES) -
+ zone_page_state(zone, NR_FILE_MAPPED) >
+ zone->min_unmapped_pages) {
+ /*
+ * Free memory by calling shrink zone with increasing
+ * priorities until we have enough memory freed.
+ */
+ priority = ZONE_RECLAIM_PRIORITY;
+ do {
+ nr_reclaimed += shrink_zone(priority, zone, &sc);
+ priority--;
+ } while (priority >= 0 && nr_reclaimed < nr_pages);
+ }
- if (nr_reclaimed < nr_pages && (zone_reclaim_mode & RECLAIM_SLAB)) {
+ if (zone_page_state(zone, NR_SLAB_RECLAIMABLE) > zone->min_slab_pages) {
/*
* shrink_slab() does not currently allow us to determine how
- * many pages were freed in this zone. So we just shake the slab
- * a bit and then go off node for this particular allocation
- * despite possibly having freed enough memory to allocate in
- * this zone. If we freed local memory then the next
- * allocations will be local again.
+ * many pages were freed in this zone. So we take the current
+ * number of slab pages and shake the slab until it is reduced
+ * by the same nr_pages that we used for reclaiming unmapped
+ * pages.
*
- * shrink_slab will free memory on all zones and may take
- * a long time.
+ * Note that shrink_slab will free memory on all zones and may
+ * take a long time.
*/
- shrink_slab(sc.nr_scanned, gfp_mask, order);
+ unsigned long limit = zone_page_state(zone,
+ NR_SLAB_RECLAIMABLE) - nr_pages;
+
+ while (shrink_slab(sc.nr_scanned, gfp_mask, order) &&
+ zone_page_state(zone, NR_SLAB_RECLAIMABLE) > limit)
+ ;
}
p->reclaim_state = NULL;
@@ -1609,7 +1622,8 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
int node_id;
/*
- * Zone reclaim reclaims unmapped file backed pages.
+ * Zone reclaim reclaims unmapped file backed pages and
+ * slab pages if we are over the defined limits.
*
* A small portion of unmapped file backed pages is needed for
* file I/O otherwise pages read by file I/O will be immediately
@@ -1618,7 +1632,9 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
* unmapped file backed pages.
*/
if (zone_page_state(zone, NR_FILE_PAGES) -
- zone_page_state(zone, NR_FILE_MAPPED) <= zone->min_unmapped_pages)
+ zone_page_state(zone, NR_FILE_MAPPED) <= zone->min_unmapped_pages
+ && zone_page_state(zone, NR_SLAB_RECLAIMABLE)
+ <= zone->min_slab_pages)
return 0;
/*