From: Roman Gushchin <guro@xxxxxx> Subject: mm: treat memory.low value inclusive If memcg's usage is equal to the memory.low value, avoid reclaiming from this cgroup while there is a surplus of reclaimable memory. This sounds more logical and also matches memory.high and memory.max behavior: both are inclusive. Empty cgroups are not considered protected, so MEMCG_LOW events are not emitted for empty cgroups, if there is no more reclaimable memory in the system. Link: http://lkml.kernel.org/r/20180406122132.GA7185@castle Signed-off-by: Roman Gushchin <guro@xxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff -puN mm/memcontrol.c~mm-treat-memorylow-value-inclusive mm/memcontrol.c --- a/mm/memcontrol.c~mm-treat-memorylow-value-inclusive +++ a/mm/memcontrol.c @@ -5344,14 +5344,14 @@ struct cgroup_subsys memory_cgrp_subsys }; /** - * mem_cgroup_low - check if memory consumption is below the normal range + * mem_cgroup_low - check if memory consumption is in the normal range * @root: the top ancestor of the sub-tree being checked * @memcg: the memory cgroup to check * * WARNING: This function is not stateless! It can only be used as part * of a top-down tree iteration, not for isolated queries. * - * Returns %true if memory consumption of @memcg is below the normal range. + * Returns %true if memory consumption of @memcg is in the normal range. * * @root is exclusive; it is never low when looked at directly * @@ -5445,7 +5445,7 @@ bool mem_cgroup_low(struct mem_cgroup *r elow = min(elow, parent_elow * low_usage / siblings_low_usage); exit: memcg->memory.elow = elow; - return usage < elow; + return usage && usage <= elow; } /** _ -- 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
