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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,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 B3981C433E0 for ; Tue, 2 Jun 2020 11:29:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8FCFE2074B for ; Tue, 2 Jun 2020 11:29:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726420AbgFBL35 (ORCPT ); Tue, 2 Jun 2020 07:29:57 -0400 Received: from out30-54.freemail.mail.aliyun.com ([115.124.30.54]:49569 "EHLO out30-54.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725919AbgFBL35 (ORCPT ); Tue, 2 Jun 2020 07:29:57 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R241e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e07484;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=9;SR=0;TI=SMTPD_---0U-NArnr_1591097390; Received: from IT-FVFX43SYHV2H.local(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0U-NArnr_1591097390) by smtp.aliyun-inc.com(127.0.0.1); Tue, 02 Jun 2020 19:29:51 +0800 Subject: Re: [PATCH] mm/compaction: avoid VM_BUG_ON(PageSlab()) in page_mapcount() To: Hugh Dickins , Andrew Morton Cc: Konstantin Khlebnikov , Vlastimil Babka , David Rientjes , "Kirill A. Shutemov" , Johannes Weiner , linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <158937872515.474360.5066096871639561424.stgit@buzz> From: Alex Shi Message-ID: <7a02e2f6-6fa8-3727-1718-887c0d1dc1cb@linux.alibaba.com> Date: Tue, 2 Jun 2020 19:28:30 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=gbk Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ÔÚ 2020/6/2 ÏÂÎç12:05, Hugh Dickins дµÀ: > Cc'ing Alex Shi, because I noticed this when trying his v11 per-memcg > lru_lock series (which appears to be a big improvement over earlier > versions, thanks in particular to Johannes's memcg swap simplifications); > and Alex's 12/16 makes a change on top of Konstantin's latter check, > which will now just be reverted. I'm not yet confident in Alex's > isolate_migratepages_block(), in part because this muddle. Hi Hugh, Yes, this could make a very tricky change on compaction behavior. I will update the patchset after next update. Thanks a lot for notice this! And looking forward to more comments on per memcg lru_lock patchset! :) Thanks Alex