From nobody Sun Feb 8 02:56:30 2026 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 AD4EAC77B7E for ; Thu, 25 May 2023 12:54:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240874AbjEYMy0 (ORCPT ); Thu, 25 May 2023 08:54:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37142 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236065AbjEYMyT (ORCPT ); Thu, 25 May 2023 08:54:19 -0400 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4B46D183 for ; Thu, 25 May 2023 05:54:18 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R861e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046049;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0VjSJ3gf_1685019253; Received: from localhost(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0VjSJ3gf_1685019253) by smtp.aliyun-inc.com; Thu, 25 May 2023 20:54:14 +0800 From: Baolin Wang To: akpm@linux-foundation.org Cc: mgorman@techsingularity.net, vbabka@suse.cz, baolin.wang@linux.alibaba.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/6] mm: compaction: skip more fully scanned pageblock Date: Thu, 25 May 2023 20:53:58 +0800 Message-Id: X-Mailer: git-send-email 2.27.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" In fast_isolate_around(), it assumes the pageblock is fully scanned if cc->nr_freepages < cc->nr_migratepages after trying to isolate some free pages, and will set skip flag to avoid scanning in future. However this can miss setting the skip flag for a fully scanned pageblock (returned 'start_pfn' is equal to 'end_pfn') in the case where cc->nr_freepages is larger than cc->nr_migratepages. So using the returned 'start_pfn' from isolate_freepages_block() and 'end_pfn' to decide if a pageblock is fully scanned makes more sense. It can also cover the case where cc->nr_freepages < cc->nr_migratepages, which means the 'start_pfn' is usually equal to 'end_pfn' except some uncommon fatal error occurs after non-strict mode isolation. Signed-off-by: Baolin Wang Acked-by: Vlastimil Babka --- mm/compaction.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/compaction.c b/mm/compaction.c index 3737c6591bfb..1e5183f39ca9 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1411,7 +1411,7 @@ fast_isolate_around(struct compact_control *cc, unsig= ned long pfn) isolate_freepages_block(cc, &start_pfn, end_pfn, &cc->freepages, 1, false= ); =20 /* Skip this pageblock in the future as it's full or nearly full */ - if (cc->nr_freepages < cc->nr_migratepages) + if (start_pfn =3D=3D end_pfn) set_pageblock_skip(page); =20 return; --=20 2.27.0