From nobody Mon Feb 9 07:06:43 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 78B72EB64DD for ; Tue, 4 Jul 2023 13:39:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231441AbjGDNjN (ORCPT ); Tue, 4 Jul 2023 09:39:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231154AbjGDNjL (ORCPT ); Tue, 4 Jul 2023 09:39:11 -0400 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 10742173E for ; Tue, 4 Jul 2023 06:38:45 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4QwP5D1Jnbz4f41VD for ; Tue, 4 Jul 2023 21:38:40 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP1 (Coremail) with SMTP id cCh0CgDXQy7fIKRkscXqMQ--.53780S3; Tue, 04 Jul 2023 21:38:40 +0800 (CST) From: Kemeng Shi To: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: shikemeng@huaweicloud.com Subject: [PATCH 1/2] mm: remove redundant check in page_vma_mapped_walk Date: Wed, 5 Jul 2023 05:39:31 +0800 Message-Id: <20230704213932.1339204-2-shikemeng@huaweicloud.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20230704213932.1339204-1-shikemeng@huaweicloud.com> References: <20230704213932.1339204-1-shikemeng@huaweicloud.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: cCh0CgDXQy7fIKRkscXqMQ--.53780S3 X-Coremail-Antispam: 1UD129KBjvdXoW7GF4DWw48GFyktF1kAFWfGrg_yoWfCFbEv3 yYvw1rXr4qqr9F93W5t3ZxKw1rt348CrWDXFW7JrZFk3s5KF1rXFW8Zr95Cr90vF4jga98 W3Zaqryjvr47ZjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUb6kFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M280x2IEY4vEnII2IxkI6r1a6r45M28IrcIa0xkI8V A2jI8067AKxVWUGwA2048vs2IY020Ec7CjxVAFwI0_Jrv_JF4l8cAvFVAK0II2c7xJM28C jxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW8JVW5JwA2z4x0Y4vE2Ix0cI 8IcVCY1x0267AKxVWxJVW8Jr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2 jsIEc7CjxVAFwI0_GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4 CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvj eVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I 1l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWU JVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r126r1DMIIYrxkI7V AKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r1j 6r4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42 IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjTRN189UUUUU 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" For PVMW_SYNC case, we always take pte lock when get first pte of PTE-mapped THP in map_pte and hold it until: 1. scan of pmd range finished or 2. scan of user input range finished or 3. user stop walk with page_vma_mapped_walk_done. In each case. pte lock will not be freed during middle scan of PTE-mapped THP. Signed-off-by: Kemeng Shi --- mm/page_vma_mapped.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index 4e448cfbc6ef..83858758e239 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -275,10 +275,6 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk = *pvmw) goto restart; } pvmw->pte++; - if ((pvmw->flags & PVMW_SYNC) && !pvmw->ptl) { - pvmw->ptl =3D pte_lockptr(mm, pvmw->pmd); - spin_lock(pvmw->ptl); - } } while (pte_none(*pvmw->pte)); =20 if (!pvmw->ptl) { --=20 2.30.0 From nobody Mon Feb 9 07:06:43 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 3A283EB64D9 for ; Tue, 4 Jul 2023 13:39:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231630AbjGDNjO (ORCPT ); Tue, 4 Jul 2023 09:39:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231131AbjGDNjL (ORCPT ); Tue, 4 Jul 2023 09:39:11 -0400 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5C308173C for ; Tue, 4 Jul 2023 06:38:44 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4QwP5D31Slz4f3rBM for ; Tue, 4 Jul 2023 21:38:40 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP1 (Coremail) with SMTP id cCh0CgDXQy7fIKRkscXqMQ--.53780S4; Tue, 04 Jul 2023 21:38:41 +0800 (CST) From: Kemeng Shi To: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: shikemeng@huaweicloud.com Subject: [PATCH 2/2] mm: correct stale comment of function check_pte Date: Wed, 5 Jul 2023 05:39:32 +0800 Message-Id: <20230704213932.1339204-3-shikemeng@huaweicloud.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20230704213932.1339204-1-shikemeng@huaweicloud.com> References: <20230704213932.1339204-1-shikemeng@huaweicloud.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: cCh0CgDXQy7fIKRkscXqMQ--.53780S4 X-Coremail-Antispam: 1UD129KBjvJXoW7WF4DJw1UZF15JF4kuFyUZFb_yoW8Cr1Upa n3Cwn5XFy8K3s09w12yrZI9r45twnxXrWSyr4rCw1fAws8Gw4kWFy5JFW8Zr4jqa1xJwnr J3y2yr43Aa48tFDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBK14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2jI8I6cxK62vIxIIY0VWUZVW8XwA2048vs2IY02 0E87I2jVAFwI0_Jryl82xGYIkIc2x26xkF7I0E14v26r1I6r4UM28lY4IEw2IIxxk0rwA2 F7IY1VAKz4vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjx v20xvEc7CjxVAFwI0_Cr0_Gr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E 87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64 kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm 72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYx C7MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_ Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUAVWUtwCIc40Y0x 0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8 JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIx AIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7sRET5lUUUUUU= = 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" Commit 2aff7a4755bed ("mm: Convert page_vma_mapped_walk to work on PFNs") replaced page with pfns in page_vma_mapped_walk structure and updated "@pvmw->page" to "@pvmw->pfn" in comment of function page_vma_mapped_walk. This patch update stale "page" to "pfn" in comment of check_pte. Signed-off-by: Kemeng Shi --- mm/page_vma_mapped.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index 83858758e239..dd0a820a0e6c 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -54,20 +54,23 @@ static bool map_pte(struct page_vma_mapped_walk *pvmw) } =20 /** - * check_pte - check if @pvmw->page is mapped at the @pvmw->pte - * @pvmw: page_vma_mapped_walk struct, includes a pair pte and page for ch= ecking + * check_pte - check if [pvmw->pfn, @pvmw->pfn + @pvmw->nr_pages) is + * mapped at the @pvmw->pte + * @pvmw: page_vma_mapped_walk struct, includes a pair pte and pfn range + * for checking * - * page_vma_mapped_walk() found a place where @pvmw->page is *potentially* + * page_vma_mapped_walk() found a place where @pvmw->pfn is *potentially* * mapped. check_pte() has to validate this. * * pvmw->pte may point to empty PTE, swap PTE or PTE pointing to * arbitrary page. * * If PVMW_MIGRATION flag is set, returns true if @pvmw->pte contains migr= ation - * entry that points to @pvmw->page or any subpage in case of THP. + * entry that points to @pvmw->pfn or [pvmw->pfn, @pvmw->pfn + @pvmw->nr_p= ages) + * in case of THP. * * If PVMW_MIGRATION flag is not set, returns true if pvmw->pte points to - * pvmw->page or any subpage in case of THP. + * pvmw->pfn or [pvmw->pfn, @pvmw->pfn + @pvmw->nr_pages) in case of THP. * * Otherwise, return false. * --=20 2.30.0