[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20160816142511.GB17006@redhat.com>
Date: Tue, 16 Aug 2016 16:25:12 +0200
From: Oleg Nesterov <oleg@...hat.com>
To: Brenden Blanco <bblanco@...mgrid.com>,
Johannes Weiner <hannes@...xchg.org>,
Michal Hocko <mhocko@...nel.org>,
Vladimir Davydov <vdavydov@...tuozzo.com>
Cc: linux-kernel@...r.kernel.org,
Peter Zijlstra <peterz@...radead.org>,
Ingo Molnar <mingo@...hat.com>,
Arnaldo Carvalho de Melo <acme@...nel.org>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Alexei Starovoitov <alexei.starovoitov@...il.com>
Subject: Re: uprobes: memory leak in enable/disable loop
On 08/16, Oleg Nesterov wrote:
>
> On 08/15, Brenden Blanco wrote:
> >
> > Hi folks,
> >
> > I think I have come across a memory leak in uprobes, which is fairly easy to
> > reproduce.
>
> At first glance this looks as a problem in memcg, add CC's...
>
> put_page(old_page) looks properly balanced, and I assume we do not need
> the additional "uncharge", we can rely on __page_cache_release().
>
> And I do not see any leak if I try to reproduce with CONFIG_MEMCG=n.
Heh. it seems that mem_cgroup_*() logic was always wrong in __replace_page().
Could you try the patch below?
Oleg.
---
--- x/kernel/events/uprobes.c
+++ x/kernel/events/uprobes.c
@@ -200,7 +200,8 @@ static int __replace_page(struct vm_area
err = 0;
unlock:
- mem_cgroup_cancel_charge(kpage, memcg, false);
+ if (err)
+ mem_cgroup_cancel_charge(kpage, memcg, false);
mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
unlock_page(page);
return err;
Powered by blists - more mailing lists