From nobody Fri Feb 13 09:50:53 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 830BEE7F154 for ; Wed, 27 Sep 2023 03:17:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233614AbjI0DRh (ORCPT ); Tue, 26 Sep 2023 23:17:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55656 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230125AbjI0DPb (ORCPT ); Tue, 26 Sep 2023 23:15:31 -0400 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5E8768A77 for ; Tue, 26 Sep 2023 19:35:58 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4RwLMD5hNpz4f3n63 for ; Wed, 27 Sep 2023 10:35:52 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP4 (Coremail) with SMTP id gCh0CgAXqtkIlRNlpd30BQ--.22085S3; Wed, 27 Sep 2023 10:35:54 +0800 (CST) From: Kemeng Shi To: akpm@linux-foundation.org, naoya.horiguchi@nec.com, osalvador@suse.de, willy@infradead.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/2] mm/page_alloc: remove unnecessary check in break_down_buddy_pages Date: Wed, 27 Sep 2023 18:35:13 +0800 Message-Id: <20230927103514.98281-2-shikemeng@huaweicloud.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20230927103514.98281-1-shikemeng@huaweicloud.com> References: <20230927103514.98281-1-shikemeng@huaweicloud.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: gCh0CgAXqtkIlRNlpd30BQ--.22085S3 X-Coremail-Antispam: 1UD129KBjvdXoW7XF4rWr4xXr18KF1UJw4Utwb_yoWDKFX_ua n7trn3tFy5KFyIgF17C3WxGrZ7Ww1F9w1xWw4YgFsxKa4UZ3Zrta1kAF95Jr4Dua95uryD u3ZxtFW2vr1S9jkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbf8YFVCjjxCrM7AC8VAFwI0_Gr0_Xr1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l87I20VAvwVAaII0Ic2I_JFv_Gryl82 xGYIkIc2x26280x7IE14v26r18M28IrcIa0xkI8VCY1x0267AKxVWUCVW8JwA2ocxC64kI II0Yj41l84x0c7CEw4AK67xGY2AK021l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7 xvwVC0I7IYx2IY6xkF7I0E14v26F4UJVW0owA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28E F7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F4 0EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_ Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JMxAIw28IcxkI7VAKI4 8JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xv wVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUAVWUtwCIc40Y0x0EwIxGrwCI42IY6xIIjx v20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20E Y4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267 AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU0PPEDUUUUU== 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" 1. We always have target in range started with next_page and full free range started with current_buddy. 2. The last split range size is 1 << low and low should be >=3D 0, then size >=3D 1. So page + size !=3D page is always true (because size > 0). As summary, current_page will not equal to target page. Signed-off-by: Kemeng Shi Acked-by: Naoya Horiguchi --- mm/page_alloc.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e18e0e20eff8..bad979493dde 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6696,10 +6696,8 @@ static void break_down_buddy_pages(struct zone *zone= , struct page *page, if (set_page_guard(zone, current_buddy, high, migratetype)) continue; =20 - if (current_buddy !=3D target) { - add_to_free_list(current_buddy, zone, high, migratetype); - set_buddy_order(current_buddy, high); - } + add_to_free_list(current_buddy, zone, high, migratetype); + set_buddy_order(current_buddy, high); } } =20 --=20 2.30.0