From: Michal Hocko <mhocko@suse.com>
To: Suren Baghdasaryan <surenb@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
David Rientjes <rientjes@google.com>,
Matthew Wilcox <willy@infradead.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Roman Gushchin <guro@fb.com>, Rik van Riel <riel@surriel.com>,
Minchan Kim <minchan@kernel.org>,
Christian Brauner <christian@brauner.io>,
Christoph Hellwig <hch@infradead.org>,
Oleg Nesterov <oleg@redhat.com>,
David Hildenbrand <david@redhat.com>,
Jann Horn <jannh@google.com>, Shakeel Butt <shakeelb@google.com>,
Andy Lutomirski <luto@kernel.org>,
Christian Brauner <christian.brauner@ubuntu.com>,
Florian Weimer <fweimer@redhat.com>,
Jan Engelhardt <jengelh@inai.de>,
Linux API <linux-api@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
kernel-team <kernel-team@android.com>,
"Kirill A. Shutemov" <kirill@shutemov.name>,
Andrea Arcangeli <aarcange@redhat.com>
Subject: Re: [PATCH 1/1] mm: prevent a race between process_mrelease and exit_mmap
Date: Thu, 11 Nov 2021 10:20:36 +0100 [thread overview]
Message-ID: <YYzgZARxi8csprIx@dhcp22.suse.cz> (raw)
In-Reply-To: <CAJuCfpHJnVG7PMhKW-Snz38az-Bv=QCFXa7DxD=KgEMbHJOi6A@mail.gmail.com>
On Wed 10-11-21 17:49:37, Suren Baghdasaryan wrote:
> On Tue, Nov 9, 2021 at 1:10 PM Suren Baghdasaryan <surenb@google.com> wrote:
> >
> > On Tue, Nov 9, 2021 at 12:10 PM Michal Hocko <mhocko@suse.com> wrote:
[...]
> > > Yes, those can run concurrently. One thing I completely forgot about is
> > > 27ae357fa82b ("mm, oom: fix concurrent munlock and oom reaper unmap, v3")
> > > which is about interaction with the munlock.
>
> Agrh! This interaction with the munlock you mentioned requires us to
> take mmap_write_lock before munlock_vma_pages_all and that prevents
> __oom_reap_task_mm from running concurrently with unmap_vmas. The
> reapers would not be as effective as they are now after such a change
> :(
__oom_reap_task_mm will not run concurrently with unmap_vmas even
with the current code. The mmap_sem barrier right before munlock code
prevents that.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2021-11-11 9:20 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-22 1:46 [PATCH 1/1] mm: prevent a race between process_mrelease and exit_mmap Suren Baghdasaryan
2021-10-22 2:24 ` Andrew Morton
2021-10-22 5:23 ` Suren Baghdasaryan
2021-10-22 8:03 ` Michal Hocko
2021-10-22 11:32 ` Matthew Wilcox
2021-10-22 12:04 ` Michal Hocko
2021-10-22 17:38 ` Suren Baghdasaryan
2021-10-27 16:08 ` Suren Baghdasaryan
2021-10-27 17:33 ` Matthew Wilcox
2021-10-27 17:42 ` Suren Baghdasaryan
2021-10-27 17:51 ` Matthew Wilcox
2021-10-27 18:00 ` Suren Baghdasaryan
2021-10-29 13:03 ` Michal Hocko
2021-10-29 16:07 ` Suren Baghdasaryan
2021-11-01 8:37 ` Michal Hocko
2021-11-01 15:44 ` Suren Baghdasaryan
2021-11-01 19:59 ` Suren Baghdasaryan
2021-11-02 7:58 ` Michal Hocko
2021-11-02 15:14 ` Suren Baghdasaryan
2021-11-09 19:01 ` Suren Baghdasaryan
2021-11-09 19:26 ` Michal Hocko
2021-11-09 19:37 ` Suren Baghdasaryan
2021-11-09 19:50 ` Michal Hocko
2021-11-09 20:02 ` Suren Baghdasaryan
2021-11-09 20:10 ` Michal Hocko
2021-11-09 21:10 ` Suren Baghdasaryan
2021-11-11 1:49 ` Suren Baghdasaryan
2021-11-11 9:20 ` Michal Hocko [this message]
2021-11-11 15:02 ` Suren Baghdasaryan
2021-11-12 8:58 ` Michal Hocko
2021-11-12 16:00 ` Suren Baghdasaryan
2021-11-09 19:41 ` Michal Hocko
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