From patchwork Thu Feb 4 11:07:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miaohe Lin X-Patchwork-Id: 12067021 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8CAB6C433DB for ; Thu, 4 Feb 2021 11:07:32 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E7A5E64DBA for ; Thu, 4 Feb 2021 11:07:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E7A5E64DBA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4F6AD6B0005; Thu, 4 Feb 2021 06:07:31 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4A6476B006C; Thu, 4 Feb 2021 06:07:31 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 39E386B006E; Thu, 4 Feb 2021 06:07:31 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0176.hostedemail.com [216.40.44.176]) by kanga.kvack.org (Postfix) with ESMTP id 1B86C6B0005 for ; Thu, 4 Feb 2021 06:07:31 -0500 (EST) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id C40F83632 for ; Thu, 4 Feb 2021 11:07:30 +0000 (UTC) X-FDA: 77780309460.05.rod30_291473f275db Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin05.hostedemail.com (Postfix) with ESMTP id A825918030C89 for ; Thu, 4 Feb 2021 11:07:30 +0000 (UTC) X-HE-Tag: rod30_291473f275db X-Filterd-Recvd-Size: 1823 Received: from szxga06-in.huawei.com (szxga06-in.huawei.com [45.249.212.32]) by imf15.hostedemail.com (Postfix) with ESMTP for ; Thu, 4 Feb 2021 11:07:29 +0000 (UTC) Received: from DGGEMS410-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4DWbMf10cXzjHTb; Thu, 4 Feb 2021 19:06:22 +0800 (CST) Received: from huawei.com (10.175.104.175) by DGGEMS410-HUB.china.huawei.com (10.3.19.210) with Microsoft SMTP Server id 14.3.498.0; Thu, 4 Feb 2021 19:07:16 +0800 From: Miaohe Lin To: CC: , , Subject: [PATCH] mm/mlock: stop counting mlocked pages when none vma is found Date: Thu, 4 Feb 2021 06:07:05 -0500 Message-ID: <20210204110705.17586-1-linmiaohe@huawei.com> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 X-Originating-IP: [10.175.104.175] X-CFilter-Loop: Reflected X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: There will be no vma satisfies addr < vm_end when find_vma() returns NULL. Thus it's meaningless to traverse the vma list below because we can't find any vma to count mlocked pages. Stop counting mlocked pages in this case to save some vma list traversal cycles. Signed-off-by: Miaohe Lin Reviewed-by: David Hildenbrand --- mm/mlock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/mlock.c b/mm/mlock.c index 73960bb3464d..f8f8cc32d03d 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -622,7 +622,7 @@ static unsigned long count_mm_mlocked_page_nr(struct mm_struct *mm, vma = find_vma(mm, start); if (vma == NULL) - vma = mm->mmap; + return 0; for (; vma ; vma = vma->vm_next) { if (start >= vma->vm_end)