mm, page_alloc: consider dirtyable memory in terms of nodes
Historically dirty pages were spread among zones but now that LRUs are per-node it is more appropriate to consider dirty pages in a node. Link: http://lkml.kernel.org/r/1467970510-21195-17-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Linus Torvalds

parent
1e6b10857f
commit
281e37265f
@@ -267,26 +267,35 @@ static void wb_min_max_ratio(struct bdi_writeback *wb,
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*/
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/**
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* zone_dirtyable_memory - number of dirtyable pages in a zone
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* @zone: the zone
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* node_dirtyable_memory - number of dirtyable pages in a node
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* @pgdat: the node
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*
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* Returns the zone's number of pages potentially available for dirty
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* page cache. This is the base value for the per-zone dirty limits.
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* Returns the node's number of pages potentially available for dirty
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* page cache. This is the base value for the per-node dirty limits.
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*/
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static unsigned long zone_dirtyable_memory(struct zone *zone)
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static unsigned long node_dirtyable_memory(struct pglist_data *pgdat)
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{
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unsigned long nr_pages;
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unsigned long nr_pages = 0;
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int z;
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for (z = 0; z < MAX_NR_ZONES; z++) {
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struct zone *zone = pgdat->node_zones + z;
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if (!populated_zone(zone))
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continue;
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nr_pages += zone_page_state(zone, NR_FREE_PAGES);
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}
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nr_pages = zone_page_state(zone, NR_FREE_PAGES);
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/*
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* Pages reserved for the kernel should not be considered
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* dirtyable, to prevent a situation where reclaim has to
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* clean pages in order to balance the zones.
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*/
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nr_pages -= min(nr_pages, zone->totalreserve_pages);
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nr_pages -= min(nr_pages, pgdat->totalreserve_pages);
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nr_pages += node_page_state(zone->zone_pgdat, NR_INACTIVE_FILE);
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nr_pages += node_page_state(zone->zone_pgdat, NR_ACTIVE_FILE);
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nr_pages += node_page_state(pgdat, NR_INACTIVE_FILE);
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nr_pages += node_page_state(pgdat, NR_ACTIVE_FILE);
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return nr_pages;
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}
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@@ -299,13 +308,24 @@ static unsigned long highmem_dirtyable_memory(unsigned long total)
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int i;
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for_each_node_state(node, N_HIGH_MEMORY) {
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for (i = 0; i < MAX_NR_ZONES; i++) {
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struct zone *z = &NODE_DATA(node)->node_zones[i];
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for (i = ZONE_NORMAL + 1; i < MAX_NR_ZONES; i++) {
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struct zone *z;
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unsigned long dirtyable;
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if (is_highmem(z))
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x += zone_dirtyable_memory(z);
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if (!is_highmem_idx(i))
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continue;
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z = &NODE_DATA(node)->node_zones[i];
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dirtyable = zone_page_state(z, NR_FREE_PAGES) +
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zone_page_state(z, NR_ZONE_LRU_FILE);
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/* watch for underflows */
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dirtyable -= min(dirtyable, high_wmark_pages(z));
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x += dirtyable;
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}
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}
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/*
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* Unreclaimable memory (kernel memory or anonymous memory
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* without swap) can bring down the dirtyable pages below
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@@ -445,23 +465,23 @@ void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty)
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}
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/**
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* zone_dirty_limit - maximum number of dirty pages allowed in a zone
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* @zone: the zone
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* node_dirty_limit - maximum number of dirty pages allowed in a node
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* @pgdat: the node
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*
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* Returns the maximum number of dirty pages allowed in a zone, based
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* on the zone's dirtyable memory.
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* Returns the maximum number of dirty pages allowed in a node, based
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* on the node's dirtyable memory.
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*/
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static unsigned long zone_dirty_limit(struct zone *zone)
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static unsigned long node_dirty_limit(struct pglist_data *pgdat)
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{
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unsigned long zone_memory = zone_dirtyable_memory(zone);
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unsigned long node_memory = node_dirtyable_memory(pgdat);
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struct task_struct *tsk = current;
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unsigned long dirty;
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if (vm_dirty_bytes)
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dirty = DIV_ROUND_UP(vm_dirty_bytes, PAGE_SIZE) *
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zone_memory / global_dirtyable_memory();
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node_memory / global_dirtyable_memory();
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else
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dirty = vm_dirty_ratio * zone_memory / 100;
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dirty = vm_dirty_ratio * node_memory / 100;
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if (tsk->flags & PF_LESS_THROTTLE || rt_task(tsk))
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dirty += dirty / 4;
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@@ -470,19 +490,30 @@ static unsigned long zone_dirty_limit(struct zone *zone)
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}
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/**
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* zone_dirty_ok - tells whether a zone is within its dirty limits
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* @zone: the zone to check
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* node_dirty_ok - tells whether a node is within its dirty limits
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* @pgdat: the node to check
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*
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* Returns %true when the dirty pages in @zone are within the zone's
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* Returns %true when the dirty pages in @pgdat are within the node's
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* dirty limit, %false if the limit is exceeded.
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*/
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bool zone_dirty_ok(struct zone *zone)
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bool node_dirty_ok(struct pglist_data *pgdat)
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{
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unsigned long limit = zone_dirty_limit(zone);
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int z;
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unsigned long limit = node_dirty_limit(pgdat);
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unsigned long nr_pages = 0;
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return zone_page_state(zone, NR_FILE_DIRTY) +
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zone_page_state(zone, NR_UNSTABLE_NFS) +
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zone_page_state(zone, NR_WRITEBACK) <= limit;
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for (z = 0; z < MAX_NR_ZONES; z++) {
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struct zone *zone = pgdat->node_zones + z;
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if (!populated_zone(zone))
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continue;
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nr_pages += zone_page_state(zone, NR_FILE_DIRTY);
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nr_pages += zone_page_state(zone, NR_UNSTABLE_NFS);
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nr_pages += zone_page_state(zone, NR_WRITEBACK);
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}
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return nr_pages <= limit;
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}
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int dirty_background_ratio_handler(struct ctl_table *table, int write,
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