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author | Mel Gorman <mgorman@techsingularity.net> | 2016-07-28 15:46:11 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-28 16:07:41 -0700 |
commit | 281e37265f2826ed401d84d6790226448ef3f0e8 (patch) | |
tree | a29b375b754c242f29082cd9e0df1a48c8109ac2 /mm/page-writeback.c | |
parent | 1e6b10857f91685c60c341703ece4ae9bb775cf3 (diff) | |
download | op-kernel-dev-281e37265f2826ed401d84d6790226448ef3f0e8.zip op-kernel-dev-281e37265f2826ed401d84d6790226448ef3f0e8.tar.gz |
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>
Diffstat (limited to 'mm/page-writeback.c')
-rw-r--r-- | mm/page-writeback.c | 91 |
1 files changed, 61 insertions, 30 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 0ada2b2..f7c0fb9 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -267,26 +267,35 @@ static void wb_min_max_ratio(struct bdi_writeback *wb, */ /** - * zone_dirtyable_memory - number of dirtyable pages in a zone - * @zone: the zone + * node_dirtyable_memory - number of dirtyable pages in a node + * @pgdat: the node * - * Returns the zone's number of pages potentially available for dirty - * page cache. This is the base value for the per-zone dirty limits. + * Returns the node's number of pages potentially available for dirty + * page cache. This is the base value for the per-node dirty limits. */ -static unsigned long zone_dirtyable_memory(struct zone *zone) +static unsigned long node_dirtyable_memory(struct pglist_data *pgdat) { - unsigned long nr_pages; + unsigned long nr_pages = 0; + int z; + + for (z = 0; z < MAX_NR_ZONES; z++) { + struct zone *zone = pgdat->node_zones + z; + + if (!populated_zone(zone)) + continue; + + nr_pages += zone_page_state(zone, NR_FREE_PAGES); + } - nr_pages = zone_page_state(zone, NR_FREE_PAGES); /* * Pages reserved for the kernel should not be considered * dirtyable, to prevent a situation where reclaim has to * clean pages in order to balance the zones. */ - nr_pages -= min(nr_pages, zone->totalreserve_pages); + nr_pages -= min(nr_pages, pgdat->totalreserve_pages); - nr_pages += node_page_state(zone->zone_pgdat, NR_INACTIVE_FILE); - nr_pages += node_page_state(zone->zone_pgdat, NR_ACTIVE_FILE); + nr_pages += node_page_state(pgdat, NR_INACTIVE_FILE); + nr_pages += node_page_state(pgdat, NR_ACTIVE_FILE); return nr_pages; } @@ -299,13 +308,24 @@ static unsigned long highmem_dirtyable_memory(unsigned long total) int i; for_each_node_state(node, N_HIGH_MEMORY) { - for (i = 0; i < MAX_NR_ZONES; i++) { - struct zone *z = &NODE_DATA(node)->node_zones[i]; + for (i = ZONE_NORMAL + 1; i < MAX_NR_ZONES; i++) { + struct zone *z; + unsigned long dirtyable; + + if (!is_highmem_idx(i)) + continue; + + z = &NODE_DATA(node)->node_zones[i]; + dirtyable = zone_page_state(z, NR_FREE_PAGES) + + zone_page_state(z, NR_ZONE_LRU_FILE); - if (is_highmem(z)) - x += zone_dirtyable_memory(z); + /* watch for underflows */ + dirtyable -= min(dirtyable, high_wmark_pages(z)); + + x += dirtyable; } } + /* * Unreclaimable memory (kernel memory or anonymous memory * without swap) can bring down the dirtyable pages below @@ -445,23 +465,23 @@ void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty) } /** - * zone_dirty_limit - maximum number of dirty pages allowed in a zone - * @zone: the zone + * node_dirty_limit - maximum number of dirty pages allowed in a node + * @pgdat: the node * - * Returns the maximum number of dirty pages allowed in a zone, based - * on the zone's dirtyable memory. + * Returns the maximum number of dirty pages allowed in a node, based + * on the node's dirtyable memory. */ -static unsigned long zone_dirty_limit(struct zone *zone) +static unsigned long node_dirty_limit(struct pglist_data *pgdat) { - unsigned long zone_memory = zone_dirtyable_memory(zone); + unsigned long node_memory = node_dirtyable_memory(pgdat); struct task_struct *tsk = current; unsigned long dirty; if (vm_dirty_bytes) dirty = DIV_ROUND_UP(vm_dirty_bytes, PAGE_SIZE) * - zone_memory / global_dirtyable_memory(); + node_memory / global_dirtyable_memory(); else - dirty = vm_dirty_ratio * zone_memory / 100; + dirty = vm_dirty_ratio * node_memory / 100; if (tsk->flags & PF_LESS_THROTTLE || rt_task(tsk)) dirty += dirty / 4; @@ -470,19 +490,30 @@ static unsigned long zone_dirty_limit(struct zone *zone) } /** - * zone_dirty_ok - tells whether a zone is within its dirty limits - * @zone: the zone to check + * node_dirty_ok - tells whether a node is within its dirty limits + * @pgdat: the node to check * - * Returns %true when the dirty pages in @zone are within the zone's + * Returns %true when the dirty pages in @pgdat are within the node's * dirty limit, %false if the limit is exceeded. */ -bool zone_dirty_ok(struct zone *zone) +bool node_dirty_ok(struct pglist_data *pgdat) { - unsigned long limit = zone_dirty_limit(zone); + int z; + unsigned long limit = node_dirty_limit(pgdat); + unsigned long nr_pages = 0; + + for (z = 0; z < MAX_NR_ZONES; z++) { + struct zone *zone = pgdat->node_zones + z; + + if (!populated_zone(zone)) + continue; + + nr_pages += zone_page_state(zone, NR_FILE_DIRTY); + nr_pages += zone_page_state(zone, NR_UNSTABLE_NFS); + nr_pages += zone_page_state(zone, NR_WRITEBACK); + } - return zone_page_state(zone, NR_FILE_DIRTY) + - zone_page_state(zone, NR_UNSTABLE_NFS) + - zone_page_state(zone, NR_WRITEBACK) <= limit; + return nr_pages <= limit; } int dirty_background_ratio_handler(struct ctl_table *table, int write, |