Re: [PATCH] mm: add config option to select the initial overcommit mode

From: Michal Hocko
Date: Fri May 13 2016 - 10:54:54 EST


On Fri 13-05-16 16:35:20, Sebastian Frias wrote:
> Hi Austin,
>
> On 05/13/2016 03:51 PM, Austin S. Hemmelgarn wrote:
> > On 2016-05-13 09:32, Sebastian Frias wrote:
> >> I didn't see that in Documentation/vm/overcommit-accounting or am I looking in the wrong place?
> > It's controlled by a sysctl value, so it's listed in Documentation/sysctl/vm.txt
> > The relevant sysctl is vm.oom_kill_allocating_task
>
> Thanks, I just read that.
> Does not look like a replacement for overcommit=never though.

No this is just an OOM strategy. I wouldn't recommend it though because
the behavior might be really time dependant - unlike the regular OOM
killer strategy to select the largest memory consumer.

And again, overcommit=never doesn't imply no-OOM. It just makes it less
likely. The kernel can consume quite some unreclaimable memory as well.
--
Michal Hocko
SUSE Labs