linux-kernel - Re: [PATCH v2] mm/oom_kill: count global and memory cgroup oom kills

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 30 May 2017 07:51:35 +0300
From:   Konstantin Khlebnikov <koct9i@...il.com>
To:     David Rientjes <rientjes@...gle.com>
Cc:     Konstantin Khlebnikov <khlebnikov@...dex-team.ru>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Michal Hocko <mhocko@...nel.org>,
        Tetsuo Handa <penguin-kernel@...ove.sakura.ne.jp>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Roman Guschin <guroan@...il.com>
Subject: Re: [PATCH v2] mm/oom_kill: count global and memory cgroup oom kills

On Tue, May 30, 2017 at 7:29 AM, David Rientjes <rientjes@...gle.com> wrote:
> On Thu, 25 May 2017, Konstantin Khlebnikov wrote:
>
>> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
>> index 04c9143a8625..dd30a045ef5b 100644
>> --- a/mm/oom_kill.c
>> +++ b/mm/oom_kill.c
>> @@ -876,6 +876,11 @@ static void oom_kill_process(struct oom_control *oc, const char *message)
>>       /* Get a reference to safely compare mm after task_unlock(victim) */
>>       mm = victim->mm;
>>       mmgrab(mm);
>> +
>> +     /* Raise event before sending signal: reaper must see this */
>
> How is the oom reaper involved here?

Task reaper - OOM event should happens before SIGCHLD.

>
>> +     count_vm_event(OOM_KILL);
>> +     mem_cgroup_count_vm_event(mm, OOM_KILL);
>> +
>>       /*
>>        * We should send SIGKILL before setting TIF_MEMDIE in order to prevent
>>        * the OOM victim from depleting the memory reserves from the user
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@...ck.org.  For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@...ck.org"> email@...ck.org </a>