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 D0D9DECDE32 for ; Wed, 17 Oct 2018 07:08:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7B26F21528 for ; Wed, 17 Oct 2018 07:08:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7B26F21528 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 S1727610AbeJQPCn (ORCPT ); Wed, 17 Oct 2018 11:02:43 -0400 Received: from mx2.suse.de ([195.135.220.15]:59734 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727257AbeJQPCn (ORCPT ); Wed, 17 Oct 2018 11:02:43 -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 909B9AD25; Wed, 17 Oct 2018 07:08:26 +0000 (UTC) Date: Wed, 17 Oct 2018 09:08:25 +0200 From: Michal Hocko To: Andrew Morton Cc: Andrea Arcangeli , Mel Gorman , David Rientjes , Vlastimil Babka , Andrea Argangeli , Zi Yan , Stefan Priebe - Profihost AG , "Kirill A. Shutemov" , linux-mm@kvack.org, LKML , Stable tree Subject: Re: [PATCH 1/2] mm: thp: relax __GFP_THISNODE for MADV_HUGEPAGE mappings Message-ID: <20181017070825.GD18839@dhcp22.suse.cz> References: <20181009130034.GD6931@suse.de> <20181009142510.GU8528@dhcp22.suse.cz> <20181009230352.GE9307@redhat.com> <20181015154459.e870c30df5c41966ffb4aed8@linux-foundation.org> <20181016074606.GH6931@suse.de> <20181016153715.b40478ff2eebe8d6cf1aead5@linux-foundation.org> <20181016231149.GJ30832@redhat.com> <20181016161643.9c16164889b4d99d6eff6763@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181016161643.9c16164889b4d99d6eff6763@linux-foundation.org> 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 Tue 16-10-18 16:16:43, Andrew Morton wrote: > On Tue, 16 Oct 2018 19:11:49 -0400 Andrea Arcangeli wrote: > > > This was a severe regression > > compared to previous kernels that made important workloads unusable > > and it starts when __GFP_THISNODE was added to THP allocations under > > MADV_HUGEPAGE. It is not a significant risk to go to the previous > > behavior before __GFP_THISNODE was added, it worked like that for > > years.@s1@s2@s1 > > 5265047ac301 ("mm, thp: really limit transparent hugepage allocation to > local node") was April 2015. That's a long time for a "severe > regression" to go unnoticed? Well, it gets some time to adopt changes in enterprise and we start seeing people reporting this issue. That is why I believe we should start with something really simple and stable tree backportable first and then build something more complex on top. -- Michal Hocko SUSE Labs