From nobody Sun Feb 8 13:09:45 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 87032C001DF for ; Tue, 1 Aug 2023 12:37:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232473AbjHAMhl (ORCPT ); Tue, 1 Aug 2023 08:37:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42030 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230244AbjHAMhj (ORCPT ); Tue, 1 Aug 2023 08:37:39 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 379F91FC6 for ; Tue, 1 Aug 2023 05:37:38 -0700 (PDT) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.57]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4RFZLk2jjKzLnyG; Tue, 1 Aug 2023 20:34:54 +0800 (CST) Received: from huawei.com (10.174.151.185) 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 15.1.2507.27; Tue, 1 Aug 2023 20:37:35 +0800 From: Miaohe Lin To: CC: , , Subject: [PATCH] mm/page_alloc: avoid unneeded alike_pages calculation Date: Tue, 1 Aug 2023 20:37:23 +0800 Message-ID: <20230801123723.2225543-1-linmiaohe@huawei.com> X-Mailer: git-send-email 2.33.0 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.174.151.185] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) 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 Content-Type: text/plain; charset="utf-8" When free_pages is 0, alike_pages is not used. So alike_pages calculation can be avoided by checking free_pages early to save cpu cycles. Also fix typo 'comparable'. It should be 'compatible' here. Signed-off-by: Miaohe Lin --- mm/page_alloc.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 8fe9ff917850..d7a357cb21ee 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1833,6 +1833,10 @@ static void steal_suitable_fallback(struct zone *zon= e, struct page *page, =20 free_pages =3D move_freepages_block(zone, page, start_type, &movable_pages); + /* moving whole block can fail due to zone boundary conditions */ + if (!free_pages) + goto single_page; + /* * Determine how many pages are compatible with our allocation. * For movable allocation, it's the number of movable pages which @@ -1854,14 +1858,9 @@ static void steal_suitable_fallback(struct zone *zon= e, struct page *page, else alike_pages =3D 0; } - - /* moving whole block can fail due to zone boundary conditions */ - if (!free_pages) - goto single_page; - /* * If a sufficient number of pages in the block are either free or of - * comparable migratability as our allocation, claim the whole block. + * compatible migratability as our allocation, claim the whole block. */ if (free_pages + alike_pages >=3D (1 << (pageblock_order-1)) || page_group_by_mobility_disabled) --=20 2.33.0