Commit b95a2f2d authored by Johannes Weiner's avatar Johannes Weiner Committed by Linus Torvalds

mm: vmscan: convert global reclaim to per-memcg LRU lists

The global per-zone LRU lists are about to go away on memcg-enabled
kernels, global reclaim must be able to find its pages on the per-memcg
LRU lists.

Since the LRU pages of a zone are distributed over all existing memory
cgroups, a scan target for a zone is complete when all memory cgroups
are scanned for their proportional share of a zone's memory.

The forced scanning of small scan targets from kswapd is limited to
zones marked unreclaimable, otherwise kswapd can quickly overreclaim by
force-scanning the LRU lists of multiple memory cgroups.
Signed-off-by: default avatarJohannes Weiner <jweiner@redhat.com>
Reviewed-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: default avatarMichal Hocko <mhocko@suse.cz>
Reviewed-by: default avatarKirill 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ad2b8e60
......@@ -1886,7 +1886,7 @@ static void get_scan_count(struct mem_cgroup_zone *mz, struct scan_control *sc,
* latencies, so it's better to scan a minimum amount there as
* well.
*/
if (current_is_kswapd())
if (current_is_kswapd() && mz->zone->all_unreclaimable)
force_scan = true;
if (!global_reclaim(sc))
force_scan = true;
......@@ -2111,16 +2111,6 @@ static void shrink_zone(int priority, struct zone *zone,
};
struct mem_cgroup *memcg;
if (global_reclaim(sc)) {
struct mem_cgroup_zone mz = {
.mem_cgroup = NULL,
.zone = zone,
};
shrink_mem_cgroup_zone(priority, &mz, sc);
return;
}
memcg = mem_cgroup_iter(root, NULL, &reclaim);
do {
struct mem_cgroup_zone mz = {
......@@ -2134,6 +2124,10 @@ static void shrink_zone(int priority, struct zone *zone,
* scanned it with decreasing priority levels until
* nr_to_reclaim had been reclaimed. This priority
* cycle is thus over after a single memcg.
*
* Direct reclaim and kswapd, on the other hand, have
* to scan all memory cgroups to fulfill the overall
* scan target for the zone.
*/
if (!global_reclaim(sc)) {
mem_cgroup_iter_break(root, memcg);
......@@ -2478,13 +2472,24 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
static void age_active_anon(struct zone *zone, struct scan_control *sc,
int priority)
{
struct mem_cgroup_zone mz = {
.mem_cgroup = NULL,
.zone = zone,
};
struct mem_cgroup *memcg;
if (inactive_anon_is_low(&mz))
shrink_active_list(SWAP_CLUSTER_MAX, &mz, sc, priority, 0);
if (!total_swap_pages)
return;
memcg = mem_cgroup_iter(NULL, NULL, NULL);
do {
struct mem_cgroup_zone mz = {
.mem_cgroup = memcg,
.zone = zone,
};
if (inactive_anon_is_low(&mz))
shrink_active_list(SWAP_CLUSTER_MAX, &mz,
sc, priority, 0);
memcg = mem_cgroup_iter(NULL, memcg, NULL);
} while (memcg);
}
/*
......
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