From 34aa1330f9b3c5783d269851d467326525207422 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Fri, 30 Jun 2006 01:55:37 -0700 Subject: [PATCH] zoned vm counters: zone_reclaim: remove /proc/sys/vm/zone_reclaim_interval The zone_reclaim_interval was necessary because we were not able to determine how many unmapped pages exist in a zone. Therefore we had to scan in intervals to figure out if any pages were unmapped. With the zoned counters and NR_ANON_PAGES we now know the number of pagecache pages and the number of mapped pages in a zone. So we can simply skip the reclaim if there is an insufficient number of unmapped pages. We use SWAP_CLUSTER_MAX as the boundary. Drop all support for /proc/sys/vm/zone_reclaim_interval. Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/sysctl/vm.txt | 13 ------------- include/linux/mmzone.h | 6 ------ include/linux/swap.h | 1 - kernel/sysctl.c | 9 --------- mm/vmscan.c | 31 ++++++++++--------------------- 5 files changed, 10 insertions(+), 50 deletions(-) diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index 2dc246af4885..86754eb390da 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -28,7 +28,6 @@ Currently, these files are in /proc/sys/vm: - block_dump - drop-caches - zone_reclaim_mode -- zone_reclaim_interval - panic_on_oom ============================================================== @@ -167,18 +166,6 @@ 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. -================================================================ - -zone_reclaim_interval: - -The time allowed for off node allocations after zone reclaim -has failed to reclaim enough pages to allow a local allocation. - -Time is set in seconds and set by default to 30 seconds. - -Reduce the interval if undesired off node allocations occur. However, too -frequent scans will have a negative impact onoff node allocation performance. - ============================================================= panic_on_oom diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 4833abd4458b..839e9a04fd49 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -178,12 +178,6 @@ struct zone { /* Zone statistics */ atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; - /* - * timestamp (in jiffies) of the last zone reclaim that did not - * result in freeing of pages. This is used to avoid repeated scans - * if all memory in the zone is in use. - */ - unsigned long last_unsuccessful_zone_reclaim; /* * prev_priority holds the scanning priority for this zone. It is diff --git a/include/linux/swap.h b/include/linux/swap.h index c41e2d6d1acc..cf6ca6e377bd 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -189,7 +189,6 @@ extern long vm_total_pages; #ifdef CONFIG_NUMA extern int zone_reclaim_mode; -extern int zone_reclaim_interval; extern int zone_reclaim(struct zone *, gfp_t, unsigned int); #else #define zone_reclaim_mode 0 diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 93a2c5398648..ee0db45e2438 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -933,15 +933,6 @@ static ctl_table vm_table[] = { .strategy = &sysctl_intvec, .extra1 = &zero, }, - { - .ctl_name = VM_ZONE_RECLAIM_INTERVAL, - .procname = "zone_reclaim_interval", - .data = &zone_reclaim_interval, - .maxlen = sizeof(zone_reclaim_interval), - .mode = 0644, - .proc_handler = &proc_dointvec_jiffies, - .strategy = &sysctl_jiffies, - }, #endif #ifdef CONFIG_X86_32 { diff --git a/mm/vmscan.c b/mm/vmscan.c index 2f0390161c0e..0960846d649f 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1517,11 +1517,6 @@ int zone_reclaim_mode __read_mostly; #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 */ -/* - * Mininum time between zone reclaim scans - */ -int zone_reclaim_interval __read_mostly = 30*HZ; - /* * Priority for ZONE_RECLAIM. This determines the fraction of pages * of a node considered for each zone_reclaim. 4 scans 1/16th of @@ -1587,16 +1582,6 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) p->reclaim_state = NULL; current->flags &= ~(PF_MEMALLOC | PF_SWAPWRITE); - - if (nr_reclaimed == 0) { - /* - * We were unable to reclaim enough pages to stay on node. We - * now allow off node accesses for a certain time period before - * trying again to reclaim pages from the local zone. - */ - zone->last_unsuccessful_zone_reclaim = jiffies; - } - return nr_reclaimed >= nr_pages; } @@ -1606,13 +1591,17 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) int node_id; /* - * Do not reclaim if there was a recent unsuccessful attempt at zone - * reclaim. In that case we let allocations go off node for the - * zone_reclaim_interval. Otherwise we would scan for each off-node - * page allocation. + * Do not reclaim if there are not enough reclaimable pages in this + * zone that would satify this allocations. + * + * All unmapped pagecache pages are reclaimable. + * + * Both counters may be temporarily off a bit so we use + * SWAP_CLUSTER_MAX as the boundary. It may also be good to + * leave a few frequently used unmapped pagecache pages around. */ - if (time_before(jiffies, - zone->last_unsuccessful_zone_reclaim + zone_reclaim_interval)) + if (zone_page_state(zone, NR_FILE_PAGES) - + zone_page_state(zone, NR_FILE_MAPPED) < SWAP_CLUSTER_MAX) return 0; /* -- cgit v1.2.3-59-g8ed1b