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[2620:137:e000::1:20]) by mx.google.com with ESMTP id d23-20020aa7d5d7000000b005234da35264si474752eds.125.2023.08.09.19.39.00; Wed, 09 Aug 2023 19:39:23 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232165AbjHJBxG (ORCPT + 99 others); Wed, 9 Aug 2023 21:53:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33996 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231435AbjHJBxF (ORCPT ); Wed, 9 Aug 2023 21:53:05 -0400 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0F27EC3 for ; Wed, 9 Aug 2023 18:53:05 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4RLqgx2JS8z4f3mHt for ; Thu, 10 Aug 2023 09:53:01 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP4 (Coremail) with SMTP id gCh0CgCXJ6r8QtRkiaZjAQ--.27199S3; Thu, 10 Aug 2023 09:53:02 +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, willy@infradead.org Cc: shikemeng@huaweicloud.com Subject: [PATCH 1/3] mm/page_alloc: correct start page when guard page debug is enabled Date: Thu, 10 Aug 2023 17:53:07 +0800 Message-Id: <20230810095309.3109107-2-shikemeng@huaweicloud.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20230810095309.3109107-1-shikemeng@huaweicloud.com> References: <20230810095309.3109107-1-shikemeng@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: gCh0CgCXJ6r8QtRkiaZjAQ--.27199S3 X-Coremail-Antispam: 1UD129KBjvdXoW7Xw15Ary8Zr4DKr1UZryrWFg_yoWDuFb_uF s7trs7tryUKa4IkF17u3WxJFZFqwn5ur4xXF1YgF13Ka4DAFn2ya1kX3WfArWDZw1xuryU u3ZrXrW5XF17ZjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUb6AFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M280x2IEY4vEnII2IxkI6r1a6r45M28IrcIa0xkI8V A2jI8067AKxVWUGwA2048vs2IY020Ec7CjxVAFwI0_JFI_Gr1l8cAvFVAK0II2c7xJM28C jxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI 8IcVCY1x0267AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E 87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64 kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm 72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYx C7MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_ Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x 0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8 JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIx AIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7sRE2NtUUUUUU= = X-CM-SenderInfo: 5vklyvpphqwq5kxd4v5lfo033gof0z/ X-CFilter-Loop: Reflected X-Spam-Status: No, score=0.1 required=5.0 tests=BAYES_00,DATE_IN_FUTURE_06_12, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1773808032812594589 X-GMAIL-MSGID: 1773808032812594589 When guard page debug is enabled and set_page_guard returns success, we miss to forward page to point to start of next split range and we will do split unexpectedly in page range without target page. Move start page update before set_page_guard to fix this. Signed-off-by: Kemeng Shi --- mm/page_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 96b7c1a7d1f2..fd93d1396ccd 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6557,6 +6557,7 @@ static void break_down_buddy_pages(struct zone *zone, struct page *page, next_page = page; current_buddy = page + size; } + page = next_page; if (set_page_guard(zone, current_buddy, high, migratetype)) continue; @@ -6564,7 +6565,6 @@ static void break_down_buddy_pages(struct zone *zone, struct page *page, if (current_buddy != target) { add_to_free_list(current_buddy, zone, high, migratetype); set_buddy_order(current_buddy, high); - page = next_page; } } } From patchwork Thu Aug 10 09:53:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kemeng Shi X-Patchwork-Id: 133674 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:b824:0:b0:3f2:4152:657d with SMTP id z4csp159196vqi; Wed, 9 Aug 2023 20:33:58 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHmy/GPwE50uueR2hqk6B2gaUh7lTm5/5w/Nw+R3Hpv8xVGGqs4vbGLhAZ/jYwliVfwJONw X-Received: by 2002:a17:902:d511:b0:1b3:fafd:11c5 with SMTP id b17-20020a170902d51100b001b3fafd11c5mr1215338plg.44.1691638437622; Wed, 09 Aug 2023 20:33:57 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1691638437; cv=none; d=google.com; s=arc-20160816; b=QOHYnS636AwTCO+QNxqiPJgVuKSlCsXUrSa3NyvvQLJ7pa23vQiskXiMCZNBy3tGSt LKNbpSWLEIyFYnRJ2pZBj2OpgGF/AWJ9cCGYcjasY6JD52xdN71YmsSoxMzY/JoUFYym 6aQuqmc/guqWebZbSX+l2CrV8YpvhSFEXEVNIKDnEPDbHYtmzBkD8DdQPx+Cnev8hW6a zlUJPi3q7kDZ0gzBDxSBUqmFdfe9J+QLa30CPMRse7o7E/YfDGaLOHLOlreucF94FxEF f3IYflTvRtDAq9Frj+H4rjLDnr+M1OSmhIfLLyvX7/F1XgA3ttaihUhFFHUh8AVzSkPC gTug== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from; bh=KfsDLmW+33ck7UhsOCgtuHEW/S7e7sfMpJT8/TxaYT4=; fh=7OUidGM7uWbpAl8VTxhM9W4yciPE2x0Gkm1foXEeriw=; b=XMYUSHuO+5carh2f8BDfGTsKbG2lIOE8n4eU3mrLEIWoLkz2IA1vodCHmCppngRG9c QY9T5/PANVsk57u1rVjJXxDCykKoq26SixK9DVx983gf17fTjmexAezo3Gx8Zavj464E FCY3Jia3uR3fIXWjgiiyZqOjkLcMlul3ouJ7tuAtpW9zvEJFoPWGm2gFvSBi0YyVm6+a 7pwbfexmU1/pLJrPdoLyLA4kXfGvZ2VjZ9tpx7UZ1PsHY4gYn7Q8lqtvIGnWaOxhLzVA AkpJe684KIt6HFLB4D1375Xh0ikiYXmS2V1Of/adFmNga5YLTOk37k47UkU0gt10EslC XA+Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id kr4-20020a170903080400b001b9e66e836dsi537800plb.587.2023.08.09.20.33.41; Wed, 09 Aug 2023 20:33:57 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232202AbjHJBxI (ORCPT + 99 others); Wed, 9 Aug 2023 21:53:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34012 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232124AbjHJBxF (ORCPT ); Wed, 9 Aug 2023 21:53:05 -0400 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6DE25C5 for ; Wed, 9 Aug 2023 18:53:05 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4RLqgx5D5jz4f3mHy for ; Thu, 10 Aug 2023 09:53:01 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP4 (Coremail) with SMTP id gCh0CgCXJ6r8QtRkiaZjAQ--.27199S4; Thu, 10 Aug 2023 09:53:02 +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, willy@infradead.org Cc: shikemeng@huaweicloud.com Subject: [PATCH 2/3] mm/page_alloc: remove unnecessary check in break_down_buddy_pages Date: Thu, 10 Aug 2023 17:53:08 +0800 Message-Id: <20230810095309.3109107-3-shikemeng@huaweicloud.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20230810095309.3109107-1-shikemeng@huaweicloud.com> References: <20230810095309.3109107-1-shikemeng@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: gCh0CgCXJ6r8QtRkiaZjAQ--.27199S4 X-Coremail-Antispam: 1UD129KBjvdXoW7XF4rWr48Kr18Wr1rWw1xZrb_yoWDAFb_ua n7tr95tFy5KF1IgF17C3W7GrWkWw1F9w4xWF4YgFsxKa4UAFnxta1kXFyrJr1Duay8ur98 W3ZxArW2qr1a9jkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbqAYFVCjjxCrM7AC8VAFwI0_Wr0E3s1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l87I20VAvwVAaII0Ic2I_JFv_Gryl82 xGYIkIc2x26280x7IE14v26r15M28IrcIa0xkI8VCY1x0267AKxVW8JVW5JwA2ocxC64kI II0Yj41l84x0c7CEw4AK67xGY2AK021l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7 xvwVC0I7IYx2IY6xkF7I0E14v26r4UJVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2 z4x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4 xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v2 6r1j6r4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6I AqYI8I648v4I1l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAq x4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q6r 43MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF 7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxV WUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjTR QNVDUUUUU X-CM-SenderInfo: 5vklyvpphqwq5kxd4v5lfo033gof0z/ X-CFilter-Loop: Reflected X-Spam-Status: No, score=0.1 required=5.0 tests=BAYES_00,DATE_IN_FUTURE_06_12, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1773811466192027497 X-GMAIL-MSGID: 1773811466192027497 1. We always have target in range started with next_page and full free range started with current_buddy. 2. The last splited range size is 1 << low and low should be >= 0, then size >= 1, then page + size and page will not interleave. As summary, current_page will not equal to target page. Signed-off-by: Kemeng Shi --- 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 fd93d1396ccd..d0b400733031 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6562,10 +6562,8 @@ static void break_down_buddy_pages(struct zone *zone, struct page *page, if (set_page_guard(zone, current_buddy, high, migratetype)) continue; - if (current_buddy != 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); } } From patchwork Thu Aug 10 09:53:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kemeng Shi X-Patchwork-Id: 133659 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:b824:0:b0:3f2:4152:657d with SMTP id z4csp134636vqi; Wed, 9 Aug 2023 19:22:24 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHaCJeF5wEeQbDDrs2UorfZq+Y/IJ3suusBQE2Mnbxy8UwRJ4uLEzq3DC2+vLqrXmltmmgW X-Received: by 2002:a17:906:845b:b0:993:da0b:8783 with SMTP id e27-20020a170906845b00b00993da0b8783mr794280ejy.3.1691634143802; Wed, 09 Aug 2023 19:22:23 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1691634143; cv=none; d=google.com; s=arc-20160816; b=KO2JKFNcYDrx80J/9SK4RZkFgFQ2lmSinUqMa5TY/l4EA0NXiEYqkaWTxYqrT6aiiG uGGJyp4l/e8sFP0o+1ohUh4SIOI3RLHjQ3Y+RlpdH4rUkOqw+gLFJFek02fVCu775SOZ +ZmdnVc8AADYVU+289ah2q9499ZPDMWHG2wrJ1xWb8Ejo90GWybECc5MIiDBT0tryw8k 08bdTA+zn8dw6V/JM8EhUwGrXVsE66srJ2Gt2DN3IHXZRTgLZIo2CmW1pF7GbJM49b3G uFFDopKzMU4/Dckwb5hupdqd8bLoyM7suqQc1apZ7zf2tEuMIp8PI7O4lRLdERJgQDSY PpKQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from; bh=Leyhi4mhcX+IdG76ZRxKEVXMYP5GGXi6Ta1WvlexVJY=; fh=7OUidGM7uWbpAl8VTxhM9W4yciPE2x0Gkm1foXEeriw=; b=XCdaz8XG3dkftTyuPGXQEomvjgjkjVqFdsDCrxTFHpcICxnboE63D0ibHMHc/jjEZ1 H38bg4rHIZzDEdy3k1PfsfRK7ib8K6rnKj+FQZkFKyu6wa7/Drbkz4P1AGlHJ4ajbv4J eDyHTRhcev6FxkVOk+8lyRRjJojYZnmke5ItUePlICjpGGMMmSUZyRaJHww/iVq0voiG XP4cCyfnouPJAEGRCJWbuPST0ipmOvhp8vvZLiMJ/94nB0RFdPH4tblMwfcBWpliVNQm YHRw0CgaL3KhmdCgyO7xK6e32TMLdFhqhT0rknJmDi/1a3BLGYIHH9kX2d+6jbMhY0dh v3xw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id 17-20020a170906059100b0099ca6e1b1f1si499937ejn.1055.2023.08.09.19.21.59; Wed, 09 Aug 2023 19:22:23 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232239AbjHJBxK (ORCPT + 99 others); Wed, 9 Aug 2023 21:53:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232136AbjHJBxG (ORCPT ); Wed, 9 Aug 2023 21:53:06 -0400 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D0EBEAC for ; Wed, 9 Aug 2023 18:53:05 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4RLqgy12Vwz4f3n6r for ; Thu, 10 Aug 2023 09:53:02 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP4 (Coremail) with SMTP id gCh0CgCXJ6r8QtRkiaZjAQ--.27199S5; Thu, 10 Aug 2023 09:53:03 +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, willy@infradead.org Cc: shikemeng@huaweicloud.com Subject: [PATCH 3/3] mm/page_alloc: remove unnecessary next_page in break_down_buddy_pages Date: Thu, 10 Aug 2023 17:53:09 +0800 Message-Id: <20230810095309.3109107-4-shikemeng@huaweicloud.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20230810095309.3109107-1-shikemeng@huaweicloud.com> References: <20230810095309.3109107-1-shikemeng@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: gCh0CgCXJ6r8QtRkiaZjAQ--.27199S5 X-Coremail-Antispam: 1UD129KBjvdXoWrZr48Cr17tF4ktryrZrW3Awb_yoWfKrg_Ga n7twnxtFy5KFyxKa17A3WxJrWDXa4F9r4xXF13tr9xAFyDJFnaq3WkXFy5CrZ8ua4ru348 uasxXrW7tr4I9jkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUb6AFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M280x2IEY4vEnII2IxkI6r1a6r45M28IrcIa0xkI8V A2jI8067AKxVWUWwA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28C jxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI 8IcVCY1x0267AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E 87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64 kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm 72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYx C7MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_ Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x 0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8 JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIx AIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7sRiyCJDUUUUU= = X-CM-SenderInfo: 5vklyvpphqwq5kxd4v5lfo033gof0z/ X-CFilter-Loop: Reflected X-Spam-Status: No, score=0.1 required=5.0 tests=BAYES_00,DATE_IN_FUTURE_06_12, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1773806964425455899 X-GMAIL-MSGID: 1773806964425455899 The next_page is only used to forward page in case target is in second harf range. Move forward page directly to remove unnecessary next_page. Signed-off-by: Kemeng Shi --- 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 d0b400733031..e884d3fd0d06 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6544,20 +6544,18 @@ static void break_down_buddy_pages(struct zone *zone, struct page *page, int migratetype) { unsigned long size = 1 << high; - struct page *current_buddy, *next_page; + struct page *current_buddy; while (high > low) { high--; size >>= 1; if (target >= &page[size]) { - next_page = page + size; current_buddy = page; + page = page + size; } else { - next_page = page; current_buddy = page + size; } - page = next_page; if (set_page_guard(zone, current_buddy, high, migratetype)) continue;