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 05AECC46475 for ; Mon, 5 Nov 2018 13:05:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CD6ED2086A for ; Mon, 5 Nov 2018 13:05:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CD6ED2086A 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 S1729793AbeKEWZZ (ORCPT ); Mon, 5 Nov 2018 17:25:25 -0500 Received: from mx2.suse.de ([195.135.220.15]:43662 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728870AbeKEWZZ (ORCPT ); Mon, 5 Nov 2018 17:25:25 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 785A9ADED; Mon, 5 Nov 2018 13:05:44 +0000 (UTC) Date: Mon, 5 Nov 2018 14:05:44 +0100 From: Michal Hocko To: Kuo-Hsin Yang Cc: linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-mm@kvack.org, Chris Wilson , Joonas Lahtinen , Peter Zijlstra , Andrew Morton , Dave Hansen Subject: Re: [PATCH v4] mm, drm/i915: mark pinned shmemfs pages as unevictable Message-ID: <20181105130544.GJ4361@dhcp22.suse.cz> References: <20181105111348.182492-1-vovoy@chromium.org> <20181105130209.GI4361@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181105130209.GI4361@dhcp22.suse.cz> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 05-11-18 14:02:09, Michal Hocko wrote: > On Mon 05-11-18 19:13:48, Kuo-Hsin Yang wrote: > > The i915 driver uses shmemfs to allocate backing storage for gem > > objects. These shmemfs pages can be pinned (increased ref count) by > > shmem_read_mapping_page_gfp(). When a lot of pages are pinned, vmscan > > wastes a lot of time scanning these pinned pages. In some extreme case, > > all pages in the inactive anon lru are pinned, and only the inactive > > anon lru is scanned due to inactive_ratio, the system cannot swap and > > invokes the oom-killer. Mark these pinned pages as unevictable to speed > > up vmscan. > > > > Export pagevec API check_move_unevictable_pages(). > > Thanks for reworking the patch. This looks much more to my taste. At > least the mm part. I haven't really looked at the the drm part. One side note. Longterm we probably want a better pinning API. It would hide this LRU manipulation implementation detail + enforce some limiting and provide a good way that the pin is longterm. People are working on this already but it is a PITA and long time to get there. -- Michal Hocko SUSE Labs