The patch titled Subject: mm: vmscan: shrink_zones: assure class zone is populated has been removed from the -mm tree. Its filename was mm-vmscan-invoke-slab-shrinkers-from-shrink_zone-fix.patch This patch was dropped because it was folded into mm-vmscan-invoke-slab-shrinkers-from-shrink_zone.patch ------------------------------------------------------ From: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> Subject: mm: vmscan: shrink_zones: assure class zone is populated Since commit 5df87d36a45e ("mm: vmscan: invoke slab shrinkers from shrink_zone()") slab shrinkers are invoked from shrink_zone. Since slab shrinkers lack the notion of memory zones, we only call slab shrinkers after scanning the highest zone suitable for allocation (class zone). However, class zone can be empty. E.g. if an x86_64 host has less than 4G of RAM, it will have only ZONE_DMA and ZONE_DMA32 populated while the class zone for most allocations, ZONE_NORMAL, will be empty. As a result, slab caches will not be scanned at all from the direct reclaim path, which may result in premature OOM killer invocations. Let's take the highest *populated* zone suitable for allocation for the class zone to fix this issue. Signed-off-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Dave Chinner <david@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/vmscan.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff -puN mm/vmscan.c~mm-vmscan-invoke-slab-shrinkers-from-shrink_zone-fix mm/vmscan.c --- a/mm/vmscan.c~mm-vmscan-invoke-slab-shrinkers-from-shrink_zone-fix +++ a/mm/vmscan.c @@ -2454,8 +2454,16 @@ static bool shrink_zones(struct zonelist for_each_zone_zonelist_nodemask(zone, z, zonelist, requested_highidx, sc->nodemask) { + enum zone_type classzone_idx; + if (!populated_zone(zone)) continue; + + classzone_idx = requested_highidx; + while (!populated_zone(zone->zone_pgdat->node_zones + + classzone_idx)) + classzone_idx--; + /* * Take care memory controller reclaiming has small influence * to global LRU. @@ -2502,7 +2510,7 @@ static bool shrink_zones(struct zonelist /* need some check for avoid more shrink_zone() */ } - if (shrink_zone(zone, sc, zone_idx(zone) == requested_highidx)) + if (shrink_zone(zone, sc, zone_idx(zone) == classzone_idx)) reclaimable = true; if (global_reclaim(sc) && _ Patches currently in -mm which might be from vdavydov@xxxxxxxxxxxxx are origin.patch memcg-__mem_cgroup_free-remove-stale-disarm_static_keys-comment.patch memcg-dont-check-mm-in-__memcg_kmem_get_cachenewpage_charge.patch memcg-do-not-abuse-memcg_kmem_skip_account.patch memcg-zap-kmem_account_flags.patch memcg-only-check-memcg_kmem_skip_account-in-__memcg_kmem_get_cache.patch memcg-turn-memcg_kmem_skip_account-into-a-bit-field.patch mm-vmscan-invoke-slab-shrinkers-from-shrink_zone.patch memcg-fix-possible-use-after-free-in-memcg_kmem_get_cache.patch slab-fix-cpuset-check-in-fallback_alloc.patch slub-fix-cpuset-check-in-get_any_partial.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html