From nobody Thu Sep 11 16:35:56 2025 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 63F94C0015E for ; Fri, 4 Aug 2023 03:07:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234023AbjHDDG4 (ORCPT ); Thu, 3 Aug 2023 23:06:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36882 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233300AbjHDDEz (ORCPT ); Thu, 3 Aug 2023 23:04:55 -0400 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 695364495 for ; Thu, 3 Aug 2023 20:04:43 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.153]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4RH9YK6R0qz4f3q32 for ; Fri, 4 Aug 2023 11:04:37 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP1 (Coremail) with SMTP id cCh0CgAXODLGasxkWSvZOg--.12542S5; Fri, 04 Aug 2023 11:04:40 +0800 (CST) From: Kemeng Shi To: linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, baolin.wang@linux.alibaba.com, mgorman@techsingularity.net, david@redhat.com Cc: shikemeng@huaweicloud.com Subject: [PATCH v3 3/8] mm/compaction: skip page block marked skip in isolate_migratepages_block Date: Fri, 4 Aug 2023 19:04:49 +0800 Message-Id: <20230804110454.2935878-4-shikemeng@huaweicloud.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20230804110454.2935878-1-shikemeng@huaweicloud.com> References: <20230804110454.2935878-1-shikemeng@huaweicloud.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: cCh0CgAXODLGasxkWSvZOg--.12542S5 X-Coremail-Antispam: 1UD129KBjvJXoW7ur1xCFWfKFyUtr1rKFyDJrb_yoW8Xr1UpF 18G3ZrtFWDWa43ZFnrtrn7uF15Cwn7JF43trZ8t348JFZ8ta4Iy3sFyas8ZrWYqr43trZ0 vF4DKFWxCa17ZaDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBE14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2jI8I6cxK62vIxIIY0VWUZVW8XwA2048vs2IY02 0E87I2jVAFwI0_JrWl82xGYIkIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2 F7IY1VAKz4vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjx v20xvEc7CjxVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2 z280aVCY1x0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0V AKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1l Ox8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErc IFxwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v2 6r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2 Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_ Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMI IF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0pRPEf5UUUUU = X-CM-SenderInfo: 5vklyvpphqwq5kxd4v5lfo033gof0z/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Move migrate_pfn to page block end when block is marked skip to avoid unnecessary scan retry of that block from upper caller. For example, compact_zone may wrongly rescan skip page block with finish_pageblock set as following: 1. cc->migrate point to the start of page block 2. compact_zone record last_migrated_pfn to cc->migrate 3. compact_zone->isolate_migratepages->isolate_migratepages_block tries to scan the block. The low_pfn maybe moved forward to middle of block because of free pages at beginning of block. 4. we find first lru page could be isolated but block was exclusive marked skip. 5. abort isolate_migratepages_block and make cc->migrate_pfn point to found lru page at middle of block. 6. compact_zone find cc->migrate_pfn and last_migrated_pfn are in the same block and wrongly rescan the block with finish_pageblock set. Signed-off-by: Kemeng Shi Reviewed-by: Baolin Wang --- mm/compaction.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/compaction.c b/mm/compaction.c index bdb03f38b7f7..9a2f0bd5394a 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1141,6 +1141,7 @@ isolate_migratepages_block(struct compact_control *cc= , unsigned long low_pfn, skip_updated =3D true; if (test_and_set_skip(cc, valid_page) && !cc->finish_pageblock) { + low_pfn =3D end_pfn; goto isolate_abort; } } --=20 2.30.0