From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: + mm-madvise-employ-mmget_still_valid-for-write-lock.patch added to -mm tree Date: Mon, 02 Mar 2020 13:16:47 -0800 Message-ID: <20200302211647.rLk1ODylX%akpm@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:52704 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726846AbgCBVQv (ORCPT ); Mon, 2 Mar 2020 16:16:51 -0500 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: alexander.h.duyck@linux.intel.com, axboe@kernel.dk, bgeffon@google.com, christian@brauner.io, dancol@google.com, hannes@cmpxchg.org, jannh@google.com, joaodias@google.com, joel@joelfernandes.org, ktkhai@virtuozzo.com, linux-man@vger.kernel.org, mhocko@suse.com, minchan@kernel.org, mm-commits@vger.kernel.org, oleksandr@redhat.com, shakeelb@google.com, sj38.park@gmail.com, sjpark@amazon.de, sonnyrao@google.com, sspatil@google.com, surenb@google.com, timmurray@google.com The patch titled Subject: mm/madvise: employ mmget_still_valid() for write lock has been added to the -mm tree. Its filename is mm-madvise-employ-mmget_still_valid-for-write-lock.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-madvise-employ-mmget_still_valid-for-write-lock.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-madvise-employ-mmget_still_valid-for-write-lock.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Oleksandr Natalenko Subject: mm/madvise: employ mmget_still_valid() for write lock Do the very same trick as we already do since 04f5866e41fb. KSM hints will require locking mmap_sem for write since they modify vm_flags, so for remote KSM hinting this additional check is needed. Link: http://lkml.kernel.org/r/20200302193630.68771-7-minchan@kernel.org Signed-off-by: Oleksandr Natalenko Signed-off-by: Minchan Kim Reviewed-by: Suren Baghdasaryan Cc: Alexander Duyck Cc: Brian Geffon Cc: Christian Brauner Cc: Daniel Colascione Cc: Jann Horn Cc: Jens Axboe Cc: Joel Fernandes Cc: Johannes Weiner Cc: John Dias Cc: Kirill Tkhai Cc: Michal Hocko Cc: Sandeep Patil Cc: SeongJae Park Cc: SeongJae Park Cc: Shakeel Butt Cc: Sonny Rao Cc: Tim Murray Cc: Signed-off-by: Andrew Morton --- mm/madvise.c | 3 +++ 1 file changed, 3 insertions(+) --- a/mm/madvise.c~mm-madvise-employ-mmget_still_valid-for-write-lock +++ a/mm/madvise.c @@ -1118,6 +1118,8 @@ int do_madvise(struct task_struct *targe if (write) { if (down_write_killable(&mm->mmap_sem)) return -EINTR; + if (current->mm != mm && !mmget_still_valid(mm)) + goto skip_mm; } else { down_read(&mm->mmap_sem); } @@ -1169,6 +1171,7 @@ int do_madvise(struct task_struct *targe } out: blk_finish_plug(&plug); +skip_mm: if (write) up_write(&mm->mmap_sem); else _ Patches currently in -mm which might be from oleksandr@redhat.com are mm-madvise-employ-mmget_still_valid-for-write-lock.patch mm-madvise-allow-ksm-hints-for-remote-api.patch