From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64830C3279B for ; Mon, 2 Jul 2018 12:56:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 28FCC25C32 for ; Mon, 2 Jul 2018 12:56:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 28FCC25C32 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752552AbeGBM4i (ORCPT ); Mon, 2 Jul 2018 08:56:38 -0400 Received: from mx2.suse.de ([195.135.220.15]:37092 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752403AbeGBM4e (ORCPT ); Mon, 2 Jul 2018 08:56:34 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 214F1AD1B; Mon, 2 Jul 2018 12:56:32 +0000 (UTC) Date: Mon, 2 Jul 2018 14:56:29 +0200 From: Michal Hocko To: Christian =?iso-8859-1?Q?K=F6nig?= Cc: LKML , "David (ChunMing) Zhou" , Paolo Bonzini , Radim =?utf-8?B?S3LEjW3DocWZ?= , Alex Deucher , David Airlie , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Doug Ledford , Jason Gunthorpe , Mike Marciniszyn , Dennis Dalessandro , Sudeep Dutt , Ashutosh Dixit , Dimitri Sivanich , Boris Ostrovsky , Juergen Gross , =?iso-8859-1?B?Suly9G1l?= Glisse , Andrea Arcangeli , kvm@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-rdma@vger.kernel.org, xen-devel@lists.xenproject.org, linux-mm@kvack.org, David Rientjes , Felix Kuehling Subject: Re: [RFC PATCH] mm, oom: distinguish blockable mode for mmu notifiers Message-ID: <20180702125629.GR19043@dhcp22.suse.cz> References: <20180622150242.16558-1-mhocko@kernel.org> <20180627074421.GF32348@dhcp22.suse.cz> <71f4184c-21ea-5af1-eeb6-bf7787614e2d@amd.com> <20180702115423.GK19043@dhcp22.suse.cz> <725cb1ad-01b0-42b5-56f0-c08c29804cb4@amd.com> <20180702122003.GN19043@dhcp22.suse.cz> <02d1d52c-f534-f899-a18c-a3169123ac7c@amd.com> <20180702123521.GO19043@dhcp22.suse.cz> <91ad1106-6bd4-7d2c-4d40-7c5be945ba36@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <91ad1106-6bd4-7d2c-4d40-7c5be945ba36@amd.com> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 02-07-18 14:39:50, Christian König wrote: [...] > Not wanting to block something as important as this, so feel free to add an > Acked-by: Christian König to the patch. Thanks a lot! > Let's rather face the next topic: Any idea how to runtime test this? This is a good question indeed. One way to do that would be triggering the OOM killer from the context which uses each of these mmu notifiers (one at the time) and see how that works. You would see the note in the log whenever the notifier would block. The primary thing to test is how often the oom reaper really had to back off completely. > I mean I can rather easily provide a test which crashes an AMD GPU, which in > turn then would mean that the MMU notifier would block forever without this > patch. Well, you do not really have to go that far. It should be sufficient to do the above. The current code would simply back of without releasing any memory. The patch should help to reclaim some memory. > But do you know a way to let the OOM killer kill a specific process? Yes, you can set its oom_score_adj to 1000 which means always select that task. -- Michal Hocko SUSE Labs