From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751329AbeDDJQs (ORCPT ); Wed, 4 Apr 2018 05:16:48 -0400 Received: from mail.netline.ch ([148.251.143.178]:39437 "EHLO netline-mail3.netline.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750772AbeDDJQr (ORCPT ); Wed, 4 Apr 2018 05:16:47 -0400 Subject: Re: [RFC] Per file OOM badness To: Lucas Stach , Michal Hocko Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Christian.Koenig@amd.com, linux-mm@kvack.org, amd-gfx@lists.freedesktop.org, Roman Gushchin References: <20180118170006.GG6584@dhcp22.suse.cz> <20180123152659.GA21817@castle.DHCP.thefacebook.com> <20180123153631.GR1526@dhcp22.suse.cz> <20180124092847.GI1526@dhcp22.suse.cz> <583f328e-ff46-c6a4-8548-064259995766@daenzer.net> <20180124110141.GA28465@dhcp22.suse.cz> <36b49523-792d-45f9-8617-32b6d9d77418@daenzer.net> <20180124115059.GC28465@dhcp22.suse.cz> <60e18da8-4d6e-dec9-7aef-ff003605d513@daenzer.net> <20180130102855.GY21609@dhcp22.suse.cz> <1522074988.1196.1.camel@pengutronix.de> From: =?UTF-8?Q?Michel_D=c3=a4nzer?= Message-ID: <3778a205-8b30-d147-b1f6-0a93d1de8beb@daenzer.net> Date: Wed, 4 Apr 2018 11:09:25 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <1522074988.1196.1.camel@pengutronix.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-CA Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018-03-26 04:36 PM, Lucas Stach wrote: > Am Dienstag, den 30.01.2018, 11:28 +0100 schrieb Michal Hocko: >> On Tue 30-01-18 10:29:10, Michel Dänzer wrote: >>> On 2018-01-24 12:50 PM, Michal Hocko wrote: >>>> On Wed 24-01-18 12:23:10, Michel Dänzer wrote: >>>>> On 2018-01-24 12:01 PM, Michal Hocko wrote: >>>>>> On Wed 24-01-18 11:27:15, Michel Dänzer wrote: >>>> >>>> [...] >>>>>>> 2. If the OOM killer kills a process which is sharing BOs >>>>>>> with another >>>>>>> process, this should result in the other process dropping >>>>>>> its references >>>>>>> to the BOs as well, at which point the memory is released. >>>>>> >>>>>> OK. How exactly are those BOs mapped to the userspace? >>>>> >>>>> I'm not sure what you're asking. Userspace mostly uses a GEM >>>>> handle to >>>>> refer to a BO. There can also be userspace CPU mappings of the >>>>> BO's >>>>> memory, but userspace doesn't need CPU mappings for all BOs and >>>>> only >>>>> creates them as needed. >>>> >>>> OK, I guess you have to bear with me some more. This whole stack >>>> is a >>>> complete uknonwn. I am mostly after finding a boundary where you >>>> can >>>> charge the allocated memory to the process so that the oom killer >>>> can >>>> consider it. Is there anything like that? Except for the proposed >>>> file >>>> handle hack? >>> >>> How about the other way around: what APIs can we use to charge / >>> "uncharge" memory to a process? If we have those, we can experiment >>> with >>> different places to call them. >> >> add_mm_counter() and I would add a new counter e.g. MM_KERNEL_PAGES. > > So is anyone still working on this? This is hurting us bad enough that > I don't want to keep this topic rotting for another year. > > If no one is currently working on this I would volunteer to give the > simple "just account private, non-shared buffers in process RSS" a > spin. Sounds good. FWIW, I think shared buffers can also be easily handled by accounting them in each process which has a reference. But that's more of a detail, shouldn't make a big difference overall either way. -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer