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=-7.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 E9FE5C4361B for ; Thu, 17 Dec 2020 19:37:02 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5E1CE2389F for ; Thu, 17 Dec 2020 19:37:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5E1CE2389F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 83F8A6B0036; Thu, 17 Dec 2020 14:37:01 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 7F0EE6B005D; Thu, 17 Dec 2020 14:37:01 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7059A6B0068; Thu, 17 Dec 2020 14:37:01 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0133.hostedemail.com [216.40.44.133]) by kanga.kvack.org (Postfix) with ESMTP id 5B4196B0036 for ; Thu, 17 Dec 2020 14:37:01 -0500 (EST) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 0449A8249980 for ; Thu, 17 Dec 2020 19:37:01 +0000 (UTC) X-FDA: 77603782242.22.boys13_000775e27437 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin22.hostedemail.com (Postfix) with ESMTP id DA8AB18038E74 for ; Thu, 17 Dec 2020 19:37:00 +0000 (UTC) X-HE-Tag: boys13_000775e27437 X-Filterd-Recvd-Size: 2803 Received: from hqnvemgate24.nvidia.com (hqnvemgate24.nvidia.com [216.228.121.143]) by imf26.hostedemail.com (Postfix) with ESMTP for ; Thu, 17 Dec 2020 19:37:00 +0000 (UTC) Received: from hqmail.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, AES256-SHA) id ; Thu, 17 Dec 2020 11:36:58 -0800 Received: from [10.2.61.104] (172.20.145.6) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 17 Dec 2020 19:36:58 +0000 Subject: Re: [PATCH 18/25] btrfs: Use readahead_batch_length To: Matthew Wilcox CC: , , References: <20201216182335.27227-1-willy@infradead.org> <20201216182335.27227-19-willy@infradead.org> <20201217121246.GD15600@casper.infradead.org> <20201217134253.GE15600@casper.infradead.org> From: John Hubbard Message-ID: Date: Thu, 17 Dec 2020 11:36:58 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:84.0) Gecko/20100101 Thunderbird/84.0 MIME-Version: 1.0 In-Reply-To: <20201217134253.GE15600@casper.infradead.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [172.20.145.6] X-ClientProxiedBy: HQMAIL111.nvidia.com (172.20.187.18) To HQMAIL107.nvidia.com (172.20.187.13) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1608233818; bh=6rL5WMauA8+LXyGXmzjXvOTi9WOgrRuLBi9GxeFHQwQ=; h=Subject:To:CC:References:From:Message-ID:Date:User-Agent: MIME-Version:In-Reply-To:Content-Type:Content-Language: Content-Transfer-Encoding:X-Originating-IP:X-ClientProxiedBy; b=HLEYh7m+YH14H3re5sfCCvg1KTEdsatWYftLMwpfepT3/eYkHw3P3Eq4rb0XgKmqZ LVFaBzKsGC26TSljIlKDxVNpKYsW1woSLuiA6iTXMp/QIa8NZi+ywUTtcm9BAkQC/s 8XHmXqz8Rb4h7gD6Kq8Cf1krkdXne6HSCxr38AlWn/OTts/nXkmfe4/abBzoNF7asE KW8knZ0bTpYRM00SzLYZl7SvfCIe4mc70RKN8pk3wfETmtcGHSqiPmQNx2gz1qG/Nc uQmsDgx4lszWHKwxqGa9s0O7yH6k6qWxr2PhzinE0v0c1HtFalpUHoD5Rv3N1zf37U wFuZozwfh4vBA== 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: On 12/17/20 5:42 AM, Matthew Wilcox wrote: > On Thu, Dec 17, 2020 at 12:12:46PM +0000, Matthew Wilcox wrote: >> ehh ... probably an off-by-one. Does subtracting 1 from contig_end fix it? >> I'll spool up a test VM shortly and try it out. > > Yes, this fixed it: > > - u64 contig_end = contig_start + readahead_batch_length(rac); > + u64 contig_end = contig_start + readahead_batch_length(rac) - 1; > Yes, confirmed on my end, too. thanks, -- John Hubbard NVIDIA