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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,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 85F6BECDE44 for ; Mon, 5 Nov 2018 09:26:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 59CBE2086C for ; Mon, 5 Nov 2018 09:26:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 59CBE2086C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=techsingularity.net 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 S1728951AbeKESpc (ORCPT ); Mon, 5 Nov 2018 13:45:32 -0500 Received: from outbound-smtp11.blacknight.com ([46.22.139.106]:56830 "EHLO outbound-smtp11.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726586AbeKESpc (ORCPT ); Mon, 5 Nov 2018 13:45:32 -0500 Received: from mail.blacknight.com (pemlinmail03.blacknight.ie [81.17.254.16]) by outbound-smtp11.blacknight.com (Postfix) with ESMTPS id E1E841C1B2C for ; Mon, 5 Nov 2018 09:26:43 +0000 (GMT) Received: (qmail 6387 invoked from network); 5 Nov 2018 09:26:43 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[37.228.229.69]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 5 Nov 2018 09:26:43 -0000 Date: Mon, 5 Nov 2018 09:26:42 +0000 From: Mel Gorman To: Aaron Lu Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Andrew Morton , "=?utf-8:iso-8859-1?B?UGF3ZcWC?= Staszewski" , Jesper Dangaard Brouer , Eric Dumazet , Tariq Toukan , Ilias Apalodimas , Yoel Caspersen , Saeed Mahameed , Michal Hocko , Vlastimil Babka , Dave Hansen Subject: Re: [PATCH 1/2] mm/page_alloc: free order-0 pages through PCP in page_frag_free() Message-ID: <20181105092642.GF23537@techsingularity.net> References: <20181105085820.6341-1-aaron.lu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20181105085820.6341-1-aaron.lu@intel.com> 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 Mon, Nov 05, 2018 at 04:58:19PM +0800, Aaron Lu wrote: > page_frag_free() calls __free_pages_ok() to free the page back to > Buddy. This is OK for high order page, but for order-0 pages, it > misses the optimization opportunity of using Per-Cpu-Pages and can > cause zone lock contention when called frequently. > > [1]: https://www.spinics.net/lists/netdev/msg531362.html > [2]: https://www.spinics.net/lists/netdev/msg531421.html > [3]: https://www.spinics.net/lists/netdev/msg531556.html > Reported-by: Paweł Staszewski > Analysed-by: Jesper Dangaard Brouer > Signed-off-by: Aaron Lu Well spotted, Acked-by: Mel Gorman -- Mel Gorman SUSE Labs