On Fri 02-05-14 11:36:28, Michal Hocko wrote: > On Wed 30-04-14 18:55:50, Johannes Weiner wrote: > > On Mon, Apr 28, 2014 at 02:26:42PM +0200, Michal Hocko wrote: > > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > > > index 19d620b3d69c..40e517630138 100644 > > > --- a/mm/memcontrol.c > > > +++ b/mm/memcontrol.c > > > @@ -2808,6 +2808,29 @@ static struct mem_cgroup > > > *mem_cgroup_lookup(unsigned short id) > > > return mem_cgroup_from_id(id); > > > } > > > > > > +/** > > > + * mem_cgroup_reclaim_eligible - checks whether given memcg is eligible > > > for the > > > + * reclaim > > > + * @memcg: target memcg for the reclaim > > > + * @root: root of the reclaim hierarchy (null for the global reclaim) > > > + * > > > + * The given group is reclaimable if it is above its low limit and the > > > same > > > + * applies for all parents up the hierarchy until root (including). > > > + */ > > > +bool mem_cgroup_reclaim_eligible(struct mem_cgroup *memcg, > > > + struct mem_cgroup *root) > > > > Could you please rename this to something that is more descriptive in > > the reclaim callsite? How about mem_cgroup_within_low_limit()? > > I have intentionally used somethig that is not low_limit specific. The > generic reclaim code does't have to care about the reason why a memcg is > not reclaimable. I agree that having follow_low_limit paramter explicit > and mem_cgroup_reclaim_eligible not is messy. So something should be > renamed. I would probably go with s@follow_low_limit@check_reclaim_eligible@ > but I do not have a strong preference.
What about this? --- >From cbe72efdf89b89d60004c84b359fc3d95db61983 Mon Sep 17 00:00:00 2001 From: Michal Hocko <[email protected]> Date: Fri, 2 May 2014 14:03:49 +0200 Subject: [PATCH] mmotm: memcg-mm-introduce-lowlimit-reclaim-fix.patch Use reclaim eligibility rather than low_limit. Generic code doesn't have to be aware of the reason why a group is not eligible. --- mm/vmscan.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 8ecf323a1c81..f195a0db5fbb 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2215,8 +2215,15 @@ static inline bool should_continue_reclaim(struct zone *zone, } } +/** + * __shrink_zone - shrinks a given zone + * + * @zone: zone to shrink + * @sc: scan control with additional reclaim parameters + * @check_memcg_eligible: check each memcg whether it is eligible for reclaim + */ static unsigned __shrink_zone(struct zone *zone, struct scan_control *sc, - bool follow_low_limit) + bool check_memcg_eligible) { unsigned long nr_reclaimed, nr_scanned; unsigned nr_scanned_groups = 0; @@ -2237,10 +2244,10 @@ static unsigned __shrink_zone(struct zone *zone, struct scan_control *sc, struct lruvec *lruvec; /* - * Memcg might be under its low limit so we have to - * skip it during the first reclaim round + * Memcg might be protected from the reclaim so we have + * to skip it during the first reclaim round */ - if (follow_low_limit && + if (check_memcg_eligible && !mem_cgroup_reclaim_eligible(memcg, root)) { /* * It would be more optimal to skip the memcg @@ -2289,8 +2296,8 @@ static void shrink_zone(struct zone *zone, struct scan_control *sc) if (!__shrink_zone(zone, sc, true)) { /* * First round of reclaim didn't find anything to reclaim - * because of low limit protection so try again and ignore - * the low limit this time. + * because of the reclaim protection so try again and ignore + * reclaim eligibility of memcgs. */ __shrink_zone(zone, sc, false); } -- 2.0.0.rc0 -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
