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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 A9813C43460 for ; Thu, 8 Apr 2021 10:47:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 80D386113A for ; Thu, 8 Apr 2021 10:47:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230424AbhDHKr1 (ORCPT ); Thu, 8 Apr 2021 06:47:27 -0400 Received: from mx2.suse.de ([195.135.220.15]:59754 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229517AbhDHKrZ (ORCPT ); Thu, 8 Apr 2021 06:47:25 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 7AA1DAF0C; Thu, 8 Apr 2021 10:47:13 +0000 (UTC) Date: Thu, 8 Apr 2021 12:47:10 +0200 From: Oscar Salvador To: Dave Hansen Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, weixugc@google.com, yang.shi@linux.alibaba.com, rientjes@google.com, ying.huang@intel.com, dan.j.williams@intel.com Subject: Re: [PATCH 05/10] mm/migrate: demote pages during reclaim Message-ID: References: <20210401183216.443C4443@viggo.jf.intel.com> <20210401183225.2EDC224F@viggo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210401183225.2EDC224F@viggo.jf.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 01, 2021 at 11:32:25AM -0700, Dave Hansen wrote: > > From: Dave Hansen > > This is mostly derived from a patch from Yang Shi: > > https://lore.kernel.org/linux-mm/1560468577-101178-10-git-send-email-yang.shi@linux.alibaba.com/ > > Add code to the reclaim path (shrink_page_list()) to "demote" data > to another NUMA node instead of discarding the data. This always > avoids the cost of I/O needed to read the page back in and sometimes > avoids the writeout cost when the pagee is dirty. > > A second pass through shrink_page_list() will be made if any demotions > fail. This essentally falls back to normal reclaim behavior in the > case that demotions fail. Previous versions of this patch may have > simply failed to reclaim pages which were eligible for demotion but > were unable to be demoted in practice. > > Note: This just adds the start of infratructure for migration. It is > actually disabled next to the FIXME in migrate_demote_page_ok(). > > Signed-off-by: Dave Hansen > Cc: Wei Xu > Cc: Yang Shi > Cc: David Rientjes > Cc: Huang Ying > Cc: Dan Williams > Cc: osalvador Reviewed-by: Oscar Salvador -- Oscar Salvador SUSE L3