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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A249BCCA47B for ; Tue, 12 Jul 2022 02:27:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230134AbiGLC1D (ORCPT ); Mon, 11 Jul 2022 22:27:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60934 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230334AbiGLC04 (ORCPT ); Mon, 11 Jul 2022 22:26:56 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB8578E1EF for ; Mon, 11 Jul 2022 19:26:49 -0700 (PDT) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4Lhl2y4VCbzlVtk; Tue, 12 Jul 2022 10:25:14 +0800 (CST) Received: from [10.174.177.76] (10.174.177.76) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 12 Jul 2022 10:26:47 +0800 Subject: Re: [PATCH] mm/compaction: fix set skip in fast_find_migrateblock To: Zhou Chuyi , References: <20220711123213.66068-1-zhouchuyi@bytedance.com> CC: Andrew Morton , linux-kernel From: Miaohe Lin Message-ID: <8af11329-93d4-3bbd-fe4c-343663c00a1b@huawei.com> Date: Tue, 12 Jul 2022 10:26:47 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20220711123213.66068-1-zhouchuyi@bytedance.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.76] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add Cc Andrew and linux-kernel email list. On 2022/7/11 20:32, Zhou Chuyi wrote: > From: zhouchuyi > > When we successfully find a pageblock in fast_find_migrateblock(), the block will be set skip-flag through set_pageblock_skip(). However, when entering isolate_migratepages_block(), the whole pageblock will be skipped due to the branch 'if (!valid_page && IS_ALIGNED(low_pfn, pageblock_nr_pages))'. Eventually we will goto isolate_abort and isolate nothing. > Signed-off-by: zhouchuyi It seems we should tweak the commit log to satisfy the checkpatch.pl first. > --- > mm/compaction.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/mm/compaction.c b/mm/compaction.c > index 1f89b969c..a1a2b50c8 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -1852,7 +1852,6 @@ static unsigned long fast_find_migrateblock(struct compact_control *cc) > pfn = cc->zone->zone_start_pfn; > cc->fast_search_fail = 0; > found_block = true; > - set_pageblock_skip(freepage); This looks like a real problem. Should we add a Fixes tag here? What's the runtime effect of it? Thanks for your patch! > break; > } > } >