From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Weiner Subject: Re: [PATCH 2/4] mm: memcontrol: reign in the CONFIG space madness Date: Sat, 12 Dec 2015 12:20:57 -0500 Message-ID: <20151212172057.GA7997@cmpxchg.org> References: <1449863653-6546-1-git-send-email-hannes@cmpxchg.org> <1449863653-6546-2-git-send-email-hannes@cmpxchg.org> <20151212163332.GC28521@esperanza> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20151212163332.GC28521@esperanza> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Vladimir Davydov Cc: Andrew Morton , Michal Hocko , linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kernel-team-b10kYP2dOMg@public.gmane.org On Sat, Dec 12, 2015 at 07:33:32PM +0300, Vladimir Davydov wrote: > On Fri, Dec 11, 2015 at 02:54:11PM -0500, Johannes Weiner wrote: > > What CONFIG_INET and CONFIG_LEGACY_KMEM guard inside the memory > > controller code is insignificant, having these conditionals is not > > worth the complication and fragility that comes with them. > > > > Signed-off-by: Johannes Weiner > > Acked-by: Vladimir Davydov > > > @@ -4374,17 +4342,11 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css) > > { > > struct mem_cgroup *memcg = mem_cgroup_from_css(css); > > > > -#ifdef CONFIG_INET > > if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket) > > static_branch_dec(&memcg_sockets_enabled_key); > > -#endif > > - > > - memcg_free_kmem(memcg); > > I wonder where the second call to memcg_free_kmem comes from. Luckily, > it couldn't result in a breakage. And now it's removed. Lol, I had to double check my trees to see what's going on as I don't remember this being part of the patch. But it looks like the double free came from the "net: drop tcp_memcontrol.c" patch and I must have removed it again during conflict resolution when rebasing this patch on top of yours. I must have thought git's auto-merge added it. However, this causes an underflow of the kmem static branch, so we will have to fix this directly in "net: drop tcp_memcontrol.c". Andrew, could you please pick this up? However, it's important to also then remove the hunk above from THIS patch, the one that deletes the excessive memcg_free_kmem(). We need exactly one memcg_free_kmem() in mem_cgroup_css_free(). :-) >From 94a14b7b0f7ed5b5ac88ca285a7e8ec3215ea59c Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Sat, 12 Dec 2015 12:14:31 -0500 Subject: [PATCH] net: drop tcp_memcontrol.c fix Signed-off-by: Johannes Weiner --- mm/memcontrol.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 5cf7fd2..a4ce8d3 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4386,8 +4386,6 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css) static_branch_dec(&memcg_sockets_enabled_key); #endif - memcg_free_kmem(memcg); - __mem_cgroup_free(memcg); } -- 2.6.4