Messages in this thread Patch in this message | | | Date | Mon, 7 Sep 2009 08:04:03 +0900 | From | Daisuke Nishimura <> | Subject | [mmotm][BUGFIX][PATCH] memcg: fix softlimit css refcnt handling(yet another one) |
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On Fri, 4 Sep 2009 19:07:26 +0900 Daisuke Nishimura <d-nishimura@mtf.biglobe.ne.jp> wrote:
> On Fri, 4 Sep 2009 16:37:58 +0900 > KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote: > > > On Fri, 4 Sep 2009 15:40:50 +0900 > > Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> wrote: > > > > Ah, one more question. What memory.usage_in_bytes shows in that case ? > > > > If not zero, charge/uncharge coalescing is guilty. > > > > > > > usage_in_bytes is 0. > > > I've confirmed by crash command that the mem_cgroup has extra ref counts. > > > > > > I'll dig more.. > > > > > BTW, do you use softlimit ? I found this but...Hmm > > > No. > I'm sorry I can't access my machine, so can't test this. > > > But I think this patch itself is needed and looks good. > I've found the cause of the issue.
Andrew, could you add this one after KAMEZAWA-san's memory-controller-soft-limit-reclaim-on-contention-v9-fix-softlimit-css-refcnt-handling.patch ?
=== From: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
refcount of the "victim" should be decremented before exiting the loop.
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> --- mm/memcontrol.c | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index ac51294..011aba6 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1133,8 +1133,10 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem, * anything, it might because there are * no reclaimable pages under this hierarchy */ - if (!check_soft || !total) + if (!check_soft || !total) { + css_put(&victim->css); break; + } /* * We want to do more targetted reclaim. * excess >> 2 is not to excessive so as to @@ -1142,8 +1144,10 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem, * coming back to reclaim from this cgroup */ if (total >= (excess >> 2) || - (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) + (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) { + css_put(&victim->css); break; + } } } if (!mem_cgroup_local_usage(&victim->stat)) {
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