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=-8.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS,USER_IN_DEF_DKIM_WL 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 67339C04EB9 for ; Thu, 6 Dec 2018 00:18:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1FF0F2082D for ; Thu, 6 Dec 2018 00:18:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ry9/2ZOD" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1FF0F2082D Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com 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 S1728873AbeLFASR (ORCPT ); Wed, 5 Dec 2018 19:18:17 -0500 Received: from mail-pl1-f195.google.com ([209.85.214.195]:45072 "EHLO mail-pl1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727575AbeLFASR (ORCPT ); Wed, 5 Dec 2018 19:18:17 -0500 Received: by mail-pl1-f195.google.com with SMTP id a14so10845868plm.12 for ; Wed, 05 Dec 2018 16:18:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:in-reply-to:message-id:references :user-agent:mime-version; bh=S0pZYoW+A1NJpap2WE+SRihOA3n3XafUr5L27VPmVX8=; b=ry9/2ZODpdViOPpqM9HnnSfDFjkxIsJqlTJp/wV508tDnyLXckxvOsOtnmoeU2M5+D ySVH81L5y84RhKN0YRJAgsDNupN+3guHL9jBBiB2DN0qFvWRs1XBP1Y2HX2nvvMuu15a 1wOTZFCqmY73E/LgGWMNhkveTIMNE6MX9CPolIjiBhSmg17CShidJkhaCqMSZCsH64Gh rZ3nO3yBwOPdyyl8JrOitffJXcZKgx4uJJzZBFGOkqk/UzBnB3l6fW7/I+mJ6vnvKyNE 2QGgsRnd+VgncFW82Zs9D3n2X1pVREa+o3PpjCK9By0lRhcP5EcoW1cWllMh6dOzwFGg XDOw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:in-reply-to:message-id :references:user-agent:mime-version; bh=S0pZYoW+A1NJpap2WE+SRihOA3n3XafUr5L27VPmVX8=; b=Es3aPtUKMmrRm7hiXDvSlLE0YIbdy8nKV/ScorOTqTJ27XIDuNUygTm88OkYmajdJW +B+bAyy3uOY9cTZ772M6kYLFekjNnB+jHSq7y7LaI6DMPpOxMLaDH8Zd6W95dTvhXjwL jg0uceO+6NVRQU94wfJcoI8eMtUtkuAuy4Ly+yBjzG3n3CbLNFMHWUXfqZ8apOQFbt0T NAImkml/1GnAs7IIqns2p06JBIpDFW8nGnSNxdg+JcfrwEtq4ITU7V8WhGE9OHGYAe8L 1s5kw51O74GCn8Trde8LOf+pKie7i/5Yh6GjRFWFOc1f5tQzuRfIvxT+dNYyjXorX0lm Bn9w== X-Gm-Message-State: AA+aEWZ16oN/DK+eLRIqc3OikY4nX62v9ePdpwKMOxhIoooyXjsJirjw P23uLZne7Q9474ZxkE13LahBEA== X-Google-Smtp-Source: AFSGD/XU4Vj6FNnw5/3SSRHK6vvTO2DhbkzPdgkUdLGNOHuvpJKfKVs3NWtyp67QQ/AyFALbZfKMTg== X-Received: by 2002:a17:902:6848:: with SMTP id f8mr25541642pln.300.1544055496060; Wed, 05 Dec 2018 16:18:16 -0800 (PST) Received: from [2620:15c:17:3:3a5:23a7:5e32:4598] ([2620:15c:17:3:3a5:23a7:5e32:4598]) by smtp.gmail.com with ESMTPSA id e86sm29048890pfb.6.2018.12.05.16.18.15 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 05 Dec 2018 16:18:15 -0800 (PST) Date: Wed, 5 Dec 2018 16:18:14 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Andrea Arcangeli cc: Linus Torvalds , mgorman@techsingularity.net, Vlastimil Babka , mhocko@kernel.org, ying.huang@intel.com, s.priebe@profihost.ag, Linux List Kernel Mailing , alex.williamson@redhat.com, lkp@01.org, kirill@shutemov.name, Andrew Morton , zi.yan@cs.rutgers.edu Subject: Re: [LKP] [mm] ac5b2c1891: vm-scalability.throughput -61.3% regression In-Reply-To: <20181205233632.GE11899@redhat.com> Message-ID: References: <20181203185954.GM31738@dhcp22.suse.cz> <20181203201214.GB3540@redhat.com> <64a4aec6-3275-a716-8345-f021f6186d9b@suse.cz> <20181204104558.GV23260@techsingularity.net> <20181205204034.GB11899@redhat.com> <20181205233632.GE11899@redhat.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 5 Dec 2018, Andrea Arcangeli wrote: > __GFP_COMPACT_ONLY gave an hope it could give some middle ground but > it shows awful compaction results, it basically destroys compaction > effectiveness and we know why (COMPACT_SKIPPED must call reclaim or > compaction can't succeed because there's not enough free memory in the > node). If somebody used MADV_HUGEPAGE compaction should still work and > not fail like that. Compaction would fail to be effective even in the > local node where __GFP_THISNODE didn't fail. Worst of all it'd fail > even on non-NUMA systems (that would be easy to fix though by making > the HPAGE_PMD_ORDER check conditional to NUMA being enabled at > runtime). > Note that in addition to COMPACT_SKIPPED that you mention, compaction can fail with COMPACT_COMPLETE, meaning the full scan has finished without freeing a hugepage, or COMPACT_DEFERRED, meaning that doing another scan is unlikely to produce a different result. COMPACT_SKIPPED makes sense to do reclaim if it can become accessible to isolate_freepages() and hopefully another allocator does not allocate from these newly freed pages before compaction can scan the zone again. For COMPACT_COMPLETE and COMPACT_DEFERRED, reclaim is unlikely to ever help.