mm: vmscan: distinguish global reclaim from global LRU scanning The traditional zone reclaim code is scanning the per-zone LRU lists during direct reclaim and kswapd, and the per-zone per-memory cgroup LRU lists when reclaiming on behalf of a memory cgroup limit. Subsequent patches will convert the traditional reclaim code to reclaim exclusively from the per-memory cgroup LRU lists. As a result, using the predicate for which LRU list is scanned will no longer be appropriate to tell global reclaim from limit reclaim. This patch adds a global_reclaim() predicate to tell direct/kswapd reclaim from memory cgroup limit reclaim and substitutes it in all places where currently scanning_global_lru() is used for that. Signed-off-by: Johannes Weiner <jweiner@redhat.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Ying Han <yinghan@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Michel Lespinasse <walken@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/vmscan.c b/mm/vmscan.c index 26f4a8a..ee4a46b 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c
@@ -153,9 +153,25 @@ static DECLARE_RWSEM(shrinker_rwsem); #ifdef CONFIG_CGROUP_MEM_RES_CTLR -#define scanning_global_lru(sc) (!(sc)->mem_cgroup) +static bool global_reclaim(struct scan_control *sc) +{ + return !sc->mem_cgroup; +} + +static bool scanning_global_lru(struct scan_control *sc) +{ + return !sc->mem_cgroup; +} #else -#define scanning_global_lru(sc) (1) +static bool global_reclaim(struct scan_control *sc) +{ + return true; +} + +static bool scanning_global_lru(struct scan_control *sc) +{ + return true; +} #endif static struct zone_reclaim_stat *get_reclaim_stat(struct zone *zone, @@ -994,7 +1010,7 @@ * back off and wait for congestion to clear because further reclaim * will encounter the same problem */ - if (nr_dirty && nr_dirty == nr_congested && scanning_global_lru(sc)) + if (nr_dirty && nr_dirty == nr_congested && global_reclaim(sc)) zone_set_flag(zone, ZONE_CONGESTED); free_hot_cold_page_list(&free_pages, 1); @@ -1313,7 +1329,7 @@ if (current_is_kswapd()) return 0; - if (!scanning_global_lru(sc)) + if (!global_reclaim(sc)) return 0; if (file) { @@ -1491,6 +1507,12 @@ if (scanning_global_lru(sc)) { nr_taken = isolate_pages_global(nr_to_scan, &page_list, &nr_scanned, sc->order, reclaim_mode, zone, 0, file); + } else { + nr_taken = mem_cgroup_isolate_pages(nr_to_scan, &page_list, + &nr_scanned, sc->order, reclaim_mode, zone, + sc->mem_cgroup, 0, file); + } + if (global_reclaim(sc)) { zone->pages_scanned += nr_scanned; if (current_is_kswapd()) __count_zone_vm_events(PGSCAN_KSWAPD, zone, @@ -1498,14 +1520,6 @@ else __count_zone_vm_events(PGSCAN_DIRECT, zone, nr_scanned); - } else { - nr_taken = mem_cgroup_isolate_pages(nr_to_scan, &page_list, - &nr_scanned, sc->order, reclaim_mode, zone, - sc->mem_cgroup, 0, file); - /* - * mem_cgroup_isolate_pages() keeps track of - * scanned pages on its own. - */ } if (nr_taken == 0) { @@ -1646,18 +1660,16 @@ &pgscanned, sc->order, reclaim_mode, zone, 1, file); - zone->pages_scanned += pgscanned; } else { nr_taken = mem_cgroup_isolate_pages(nr_pages, &l_hold, &pgscanned, sc->order, reclaim_mode, zone, sc->mem_cgroup, 1, file); - /* - * mem_cgroup_isolate_pages() keeps track of - * scanned pages on its own. - */ } + if (global_reclaim(sc)) + zone->pages_scanned += pgscanned; + reclaim_stat->recent_scanned[file] += nr_taken; __count_zone_vm_events(PGREFILL, zone, pgscanned); @@ -1827,7 +1839,7 @@ static int vmscan_swappiness(struct scan_control *sc) { - if (scanning_global_lru(sc)) + if (global_reclaim(sc)) return vm_swappiness; return mem_cgroup_swappiness(sc->mem_cgroup); } @@ -1862,9 +1874,9 @@ * latencies, so it's better to scan a minimum amount there as * well. */ - if (scanning_global_lru(sc) && current_is_kswapd()) + if (current_is_kswapd()) force_scan = true; - if (!scanning_global_lru(sc)) + if (!global_reclaim(sc)) force_scan = true; /* If we have no swap space, do not bother scanning anon pages. */ @@ -1881,7 +1893,7 @@ file = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_FILE) + zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE); - if (scanning_global_lru(sc)) { + if (global_reclaim(sc)) { free = zone_page_state(zone, NR_FREE_PAGES); /* If we have very few page cache pages, force-scan anon pages. */ @@ -2114,7 +2126,7 @@ * Take care memory controller reclaiming has small influence * to global LRU. */ - if (scanning_global_lru(sc)) { + if (global_reclaim(sc)) { if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) continue; if (zone->all_unreclaimable && priority != DEF_PRIORITY) @@ -2212,7 +2224,7 @@ get_mems_allowed(); delayacct_freepages_start(); - if (scanning_global_lru(sc)) + if (global_reclaim(sc)) count_vm_event(ALLOCSTALL); for (priority = DEF_PRIORITY; priority >= 0; priority--) { @@ -2226,7 +2238,7 @@ * Don't shrink slabs when reclaiming memory from * over limit cgroups */ - if (scanning_global_lru(sc)) { + if (global_reclaim(sc)) { unsigned long lru_pages = 0; for_each_zone_zonelist(zone, z, zonelist, gfp_zone(sc->gfp_mask)) { @@ -2288,7 +2300,7 @@ return 0; /* top priority shrink_zones still had more to do? don't OOM, then */ - if (scanning_global_lru(sc) && !all_unreclaimable(zonelist, sc)) + if (global_reclaim(sc) && !all_unreclaimable(zonelist, sc)) return 1; return 0;