[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 <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Christoph Lameter
Linus Torvalds
parent
f3dbd34460
commit
34aa1330f9
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@ -28,7 +28,6 @@ Currently, these files are in /proc/sys/vm:
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- block_dump
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- drop-caches
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- zone_reclaim_mode
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- zone_reclaim_interval
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- panic_on_oom
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==============================================================
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@ -167,18 +166,6 @@ use of files and builds up large slab caches. However, the slab
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shrink operation is global, may take a long time and free slabs
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in all nodes of the system.
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================================================================
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zone_reclaim_interval:
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The time allowed for off node allocations after zone reclaim
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has failed to reclaim enough pages to allow a local allocation.
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Time is set in seconds and set by default to 30 seconds.
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Reduce the interval if undesired off node allocations occur. However, too
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frequent scans will have a negative impact onoff node allocation performance.
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=============================================================
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panic_on_oom
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@ -178,12 +178,6 @@ struct zone {
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/* Zone statistics */
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atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
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/*
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* timestamp (in jiffies) of the last zone reclaim that did not
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* result in freeing of pages. This is used to avoid repeated scans
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* if all memory in the zone is in use.
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*/
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unsigned long last_unsuccessful_zone_reclaim;
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/*
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* prev_priority holds the scanning priority for this zone. It is
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@ -189,7 +189,6 @@ extern long vm_total_pages;
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#ifdef CONFIG_NUMA
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extern int zone_reclaim_mode;
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extern int zone_reclaim_interval;
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extern int zone_reclaim(struct zone *, gfp_t, unsigned int);
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#else
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#define zone_reclaim_mode 0
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@ -933,15 +933,6 @@ static ctl_table vm_table[] = {
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.strategy = &sysctl_intvec,
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.extra1 = &zero,
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},
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{
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.ctl_name = VM_ZONE_RECLAIM_INTERVAL,
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.procname = "zone_reclaim_interval",
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.data = &zone_reclaim_interval,
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.maxlen = sizeof(zone_reclaim_interval),
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.mode = 0644,
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.proc_handler = &proc_dointvec_jiffies,
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.strategy = &sysctl_jiffies,
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},
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#endif
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#ifdef CONFIG_X86_32
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{
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31
mm/vmscan.c
31
mm/vmscan.c
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@ -1517,11 +1517,6 @@ int zone_reclaim_mode __read_mostly;
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#define RECLAIM_SWAP (1<<2) /* Swap pages out during reclaim */
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#define RECLAIM_SLAB (1<<3) /* Do a global slab shrink if the zone is out of memory */
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/*
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* Mininum time between zone reclaim scans
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*/
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int zone_reclaim_interval __read_mostly = 30*HZ;
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/*
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* Priority for ZONE_RECLAIM. This determines the fraction of pages
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* of a node considered for each zone_reclaim. 4 scans 1/16th of
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@ -1587,16 +1582,6 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
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p->reclaim_state = NULL;
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current->flags &= ~(PF_MEMALLOC | PF_SWAPWRITE);
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if (nr_reclaimed == 0) {
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/*
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* We were unable to reclaim enough pages to stay on node. We
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* now allow off node accesses for a certain time period before
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* trying again to reclaim pages from the local zone.
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*/
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zone->last_unsuccessful_zone_reclaim = jiffies;
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}
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return nr_reclaimed >= nr_pages;
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}
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@ -1606,13 +1591,17 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
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int node_id;
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/*
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* Do not reclaim if there was a recent unsuccessful attempt at zone
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* reclaim. In that case we let allocations go off node for the
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* zone_reclaim_interval. Otherwise we would scan for each off-node
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* page allocation.
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* Do not reclaim if there are not enough reclaimable pages in this
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* zone that would satify this allocations.
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*
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* All unmapped pagecache pages are reclaimable.
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*
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* Both counters may be temporarily off a bit so we use
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* SWAP_CLUSTER_MAX as the boundary. It may also be good to
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* leave a few frequently used unmapped pagecache pages around.
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*/
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if (time_before(jiffies,
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zone->last_unsuccessful_zone_reclaim + zone_reclaim_interval))
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if (zone_page_state(zone, NR_FILE_PAGES) -
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zone_page_state(zone, NR_FILE_MAPPED) < SWAP_CLUSTER_MAX)
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return 0;
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/*
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