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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 7DCDCC352AA for ; Wed, 2 Oct 2019 10:35:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3F2C0218DE for ; Wed, 2 Oct 2019 10:35:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570012518; bh=UMwnsS5o+0MCabaprV9j6oxEf3KZ6oes3cDnTFBxY9c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=WpP/8vdHGR2OLsW4y81vVfU+oIZT6z/13k6P+uZJJe9hEj5SoG0iYQF/+eXCj6rK0 09Xt+9FzHKUg4TiEEMxXH7OPHoCT5e9hyRgpzvlKNp4jZyxlv8KnSjDZBmjjieFMO1 LYlHFYXTgyLuh0VcNHjA2OijnjgON10y9ss5LmYs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728026AbfJBKfR (ORCPT ); Wed, 2 Oct 2019 06:35:17 -0400 Received: from mx2.suse.de ([195.135.220.15]:60374 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725999AbfJBKfQ (ORCPT ); Wed, 2 Oct 2019 06:35:16 -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 33B85B028; Wed, 2 Oct 2019 10:35:15 +0000 (UTC) Date: Wed, 2 Oct 2019 12:34:22 +0200 From: Michal Hocko To: David Rientjes Cc: Vlastimil Babka , Linus Torvalds , Andrea Arcangeli , Andrew Morton , Mel Gorman , "Kirill A. Shutemov" , Linux Kernel Mailing List , Linux-MM Subject: Re: [patch for-5.3 0/4] revert immediate fallback to remote hugepages Message-ID: <20191002103422.GJ15624@dhcp22.suse.cz> References: <20190909193020.GD2063@dhcp22.suse.cz> <20190925070817.GH23050@dhcp22.suse.cz> <20190927074803.GB26848@dhcp22.suse.cz> <20190930112817.GC15942@dhcp22.suse.cz> <20191001054343.GA15624@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 01-10-19 23:54:14, Vlastimil Babka wrote: > On 10/1/19 10:31 PM, David Rientjes wrote: [...] > > If > > hugetlb wants to stress this to the fullest extent possible, it already > > appropriately uses __GFP_RETRY_MAYFAIL. > > Which doesn't work anymore right now, and should again after this patch. I didn't get to fully digest the patch Vlastimil is proposing. (Ab)using __GFP_NORETRY is quite subtle but it is already in place with some explanation and a reference to THPs. So while I am not really happy it is at least something you can reason about. b39d0ee2632d ("mm, page_alloc: avoid expensive reclaim when compaction may not succeed") on the other hand has added a much more wider change which has clearly broken hugetlb and any __GFP_RETRY_MAYFAIL user of pageblock_order sized allocations. And that is much worse and something I was pointing at during the review and those concerns were never really addressed before merging. In any case this is something to be fixed ASAP. Do you have any better proposa? I do not assume you would be proposing yet another revert. -- Michal Hocko SUSE Labs