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 X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 97F6CC3A5A1 for ; Sun, 25 Aug 2019 07:25:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6DE7C21848 for ; Sun, 25 Aug 2019 07:25:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=zoho.com header.i=yehs2007@zoho.com header.b="Vw/993Q/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727045AbfHYHZO (ORCPT ); Sun, 25 Aug 2019 03:25:14 -0400 Received: from sender-pp-o92.zoho.com ([135.84.80.237]:25499 "EHLO sender-pp-o92.zoho.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725809AbfHYHZN (ORCPT ); Sun, 25 Aug 2019 03:25:13 -0400 ARC-Seal: i=1; a=rsa-sha256; t=1566717906; cv=none; d=zoho.com; s=zohoarc; b=Yjj9Rt7PSlWq0HPfmzbLhvQKdcqom6NrNe9llRsWF7aVQMOXiV8AjiXUqO365DJ9eM5icwuJWFKadheAf2j1bbMRrISZ5aPec/WihxbFFM1SA4mheQvWpQNvDfmn5Py6jhON/AcmRR+EbqFSGXLOnuZsQGqE2FH//NHhiDwTPH4= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1566717906; h=Cc:Date:From:In-Reply-To:Message-ID:References:Subject:To:ARC-Authentication-Results; bh=Ll1ddxjlpuzcBFEPUI7g0gZvBDFbmDed0ou/3799LFI=; b=hV8XNvO8xGgJRInjwl3m2YHfosYI13JUkRBMtglehScoNS+VOAmXYwTDqdd5VonySa4+AaQMgUn2w7Aen9/IkxVysyGe9FlPM+ceTNhX23fbUHrLAKPF9ixlr6CJS/TFRWvweZmsQuZkn61eeZzM59Ryw1QcYCMwbkxmRdbyztQ= ARC-Authentication-Results: i=1; mx.zoho.com; dkim=pass header.i=zoho.com; spf=pass smtp.mailfrom=yehs2007@zoho.com; dmarc=pass header.from= header.from= DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=zapps768; d=zoho.com; h=from:to:cc:subject:date:message-id:in-reply-to:references; b=h8bNdcwCOcnyX9C96B/SV8Gcd5TJBr05qUyw+Ya95aHltSrT1fEdPfZBFfOUDhsk0JNlQNoucCBy uQVk6ioHUUH5IrAkKeo+LAKHbthlCpewJJEAvjU3X6Pec2VdIkB1 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1566717906; s=zm2019; d=zoho.com; i=yehs2007@zoho.com; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; l=1017; bh=Ll1ddxjlpuzcBFEPUI7g0gZvBDFbmDed0ou/3799LFI=; b=Vw/993Q/FtiTHaRCQNPB36qpst0AacARkWXRYwkz9T3O0WqHYSAzmlfJqcIZWhz4 SwNI6wUdgoDjY4VwlCg0A2BmT166xBAlA32FGQnasKVw/LH9xNoyLcuG7KDEhkGzYtL UTrv4SIHrXYIWpaCtVHbsFjjcVJkbQKFlQIsnVVU= Received: from YEHS1XR3054QMS.lenovo.com (123.120.58.107 [123.120.58.107]) by mx.zohomail.com with SMTPS id 1566717905963339.9025705087869; Sun, 25 Aug 2019 00:25:05 -0700 (PDT) From: Huaisheng Ye To: mpatocka@redhat.com, snitzer@redhat.com, agk@redhat.com Cc: prarit@redhat.com, tyu1@lenovo.com, dm-devel@redhat.com, linux-kernel@vger.kernel.org, Huaisheng Ye Subject: [PATCH 2/3] dm writecache: add unlikely for getting two block with same LBA Date: Sun, 25 Aug 2019 15:24:32 +0800 Message-Id: <20190825072433.2628-3-yehs2007@zoho.com> X-Mailer: git-send-email 2.17.0.windows.1 In-Reply-To: <20190825072433.2628-1-yehs2007@zoho.com> References: <20190825072433.2628-1-yehs2007@zoho.com> X-ZohoMailClient: External Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Huaisheng Ye In function writecache_writeback, entries g and f has same original sector only happens at entry f has been committed, but entry g has NOT yet. The probability of this happening is very low in the following 256 blocks at most of entry e. Signed-off-by: Huaisheng Ye Acked-by: Mikulas Patocka --- drivers/md/dm-writecache.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c index 5c7009d..3643084 100644 --- a/drivers/md/dm-writecache.c +++ b/drivers/md/dm-writecache.c @@ -1628,8 +1628,8 @@ static void writecache_writeback(struct work_struct *work) if (unlikely(!next_node)) break; g = container_of(next_node, struct wc_entry, rb_node); - if (read_original_sector(wc, g) == - read_original_sector(wc, f)) { + if (unlikely(read_original_sector(wc, g) == + read_original_sector(wc, f))) { f = g; continue; } -- 1.8.3.1