From mboxrd@z Thu Jan 1 00:00:00 1970 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 175E8C433FE for ; Thu, 10 Feb 2022 14:21:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242824AbiBJOVX (ORCPT ); Thu, 10 Feb 2022 09:21:23 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:38510 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236634AbiBJOVS (ORCPT ); Thu, 10 Feb 2022 09:21:18 -0500 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 387E221B for ; Thu, 10 Feb 2022 06:21:17 -0800 (PST) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4Jvf646DzLzbkBd; Thu, 10 Feb 2022 22:20:12 +0800 (CST) Received: from huawei.com (10.175.124.27) 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 15.1.2308.21; Thu, 10 Feb 2022 22:21:14 +0800 From: Miaohe Lin To: , CC: , , Subject: [PATCH 2/8] mm/memory-failure.c: avoid walking page table when vma_address() return -EFAULT Date: Thu, 10 Feb 2022 22:17:27 +0800 Message-ID: <20220210141733.1908-3-linmiaohe@huawei.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20220210141733.1908-1-linmiaohe@huawei.com> References: <20220210141733.1908-1-linmiaohe@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) 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 It's unnecessary to walk the page table when vma_address() return -EFAULT. Return early if so to save some cpu cycles. Signed-off-by: Miaohe Lin --- mm/memory-failure.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index b3ff7e99a421..f86819145ea8 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -315,6 +315,8 @@ static unsigned long dev_pagemap_mapping_shift(struct page *page, pmd_t *pmd; pte_t *pte; + if (address == -EFAULT) + return 0; pgd = pgd_offset(vma->vm_mm, address); if (!pgd_present(*pgd)) return 0; -- 2.23.0