From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Hocko Subject: Re: [PATCH] mm: memcontrol: fix percpu vmstats and vmevents flush Date: Fri, 30 Aug 2019 07:49:31 +0200 Message-ID: <20190830054931.GN28313@dhcp22.suse.cz> References: <20190829203110.129263-1-shakeelb@google.com> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20190829203110.129263-1-shakeelb@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Shakeel Butt Cc: Roman Gushchin , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Johannes Weiner , Vladimir Davydov , Andrew Morton , stable@vger.kernel.org On Thu 29-08-19 13:31:10, Shakeel Butt wrote: > Instead of using raw_cpu_read() use per_cpu() to read the actual data of > the corresponding cpu otherwise we will be reading the data of the > current cpu for the number of online CPUs. > > Fixes: bb65f89b7d3d ("mm: memcontrol: flush percpu vmevents before releasing memcg") > Fixes: c350a99ea2b1 ("mm: memcontrol: flush percpu vmstats before releasing memcg") > Signed-off-by: Shakeel Butt > Cc: Roman Gushchin > Cc: Michal Hocko > Cc: Johannes Weiner > Cc: Vladimir Davydov > Cc: Andrew Morton > Cc: Ups, missed that when reviewing. Sorry about that. Acked-by: Michal Hocko > --- > > Note: The buggy patches were marked for stable therefore adding Cc to > stable. > > mm/memcontrol.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 26e2999af608..f4e60ee8b845 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -3271,7 +3271,7 @@ static void memcg_flush_percpu_vmstats(struct mem_cgroup *memcg) > > for_each_online_cpu(cpu) > for (i = 0; i < MEMCG_NR_STAT; i++) > - stat[i] += raw_cpu_read(memcg->vmstats_percpu->stat[i]); > + stat[i] += per_cpu(memcg->vmstats_percpu->stat[i], cpu); > > for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) > for (i = 0; i < MEMCG_NR_STAT; i++) > @@ -3286,8 +3286,8 @@ static void memcg_flush_percpu_vmstats(struct mem_cgroup *memcg) > > for_each_online_cpu(cpu) > for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) > - stat[i] += raw_cpu_read( > - pn->lruvec_stat_cpu->count[i]); > + stat[i] += per_cpu( > + pn->lruvec_stat_cpu->count[i], cpu); > > for (pi = pn; pi; pi = parent_nodeinfo(pi, node)) > for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) > @@ -3306,8 +3306,8 @@ static void memcg_flush_percpu_vmevents(struct mem_cgroup *memcg) > > for_each_online_cpu(cpu) > for (i = 0; i < NR_VM_EVENT_ITEMS; i++) > - events[i] += raw_cpu_read( > - memcg->vmstats_percpu->events[i]); > + events[i] += per_cpu(memcg->vmstats_percpu->events[i], > + cpu); > > for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) > for (i = 0; i < NR_VM_EVENT_ITEMS; i++) > -- > 2.23.0.187.g17f5b7556c-goog > -- Michal Hocko SUSE Labs