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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 19F44C7618B for ; Fri, 26 Jul 2019 08:12:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D9A4021880 for ; Fri, 26 Jul 2019 08:12:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726329AbfGZIMa (ORCPT ); Fri, 26 Jul 2019 04:12:30 -0400 Received: from mx2.suse.de ([195.135.220.15]:58086 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725815AbfGZIMa (ORCPT ); Fri, 26 Jul 2019 04:12:30 -0400 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 206DAB62D; Fri, 26 Jul 2019 08:12:29 +0000 (UTC) Date: Fri, 26 Jul 2019 09:12:25 +0100 From: Mel Gorman To: Hillf Danton Cc: Mike Kravetz , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michal Hocko , Vlastimil Babka , Johannes Weiner , Andrew Morton Subject: Re: [RFC PATCH 1/3] mm, reclaim: make should_continue_reclaim perform dryrun detection Message-ID: <20190726081225.GF2708@suse.de> References: <20190724175014.9935-1-mike.kravetz@oracle.com> <20190724175014.9935-2-mike.kravetz@oracle.com> <20190725080551.GB2708@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20190725080551.GB2708@suse.de> 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 > From: Hillf Danton > Subject: [RFC PATCH 1/3] mm, reclaim: make should_continue_reclaim perform dryrun detection > > Address the issue of should_continue_reclaim continuing true too often > for __GFP_RETRY_MAYFAIL attempts when !nr_reclaimed and nr_scanned. > This could happen during hugetlb page allocation causing stalls for > minutes or hours. > > We can stop reclaiming pages if compaction reports it can make a progress. > A code reshuffle is needed to do that. And it has side-effects, however, > with allocation latencies in other cases but that would come at the cost > of potential premature reclaim which has consequences of itself. > > We can also bail out of reclaiming pages if we know that there are not > enough inactive lru pages left to satisfy the costly allocation. > > We can give up reclaiming pages too if we see dryrun occur, with the > certainty of plenty of inactive pages. IOW with dryrun detected, we are > sure we have reclaimed as many pages as we could. > > Cc: Mike Kravetz > Cc: Mel Gorman > Cc: Michal Hocko > Cc: Vlastimil Babka > Cc: Johannes Weiner > Signed-off-by: Hillf Danton Acked-by: Mel Gorman Thanks Hillf -- Mel Gorman SUSE Labs