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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 F123DC4361B for ; Thu, 17 Dec 2020 13:42:58 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 58D89238EF for ; Thu, 17 Dec 2020 13:42:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 58D89238EF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 6A7C06B0036; Thu, 17 Dec 2020 08:42:57 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 658BE6B0070; Thu, 17 Dec 2020 08:42:57 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 59EB86B0036; Thu, 17 Dec 2020 08:42:57 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0149.hostedemail.com [216.40.44.149]) by kanga.kvack.org (Postfix) with ESMTP id 41A086B0036 for ; Thu, 17 Dec 2020 08:42:57 -0500 (EST) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 13270180AD81F for ; Thu, 17 Dec 2020 13:42:57 +0000 (UTC) X-FDA: 77602889994.10.dogs11_0d07f9c27435 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin10.hostedemail.com (Postfix) with ESMTP id E441916A4B7 for ; Thu, 17 Dec 2020 13:42:56 +0000 (UTC) X-HE-Tag: dogs11_0d07f9c27435 X-Filterd-Recvd-Size: 2091 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf17.hostedemail.com (Postfix) with ESMTP for ; Thu, 17 Dec 2020 13:42:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=/8lQifGcjmxPMERF4ubMZzEbBgP5tWrAqrwbgQG01/Q=; b=Tv+BEuMqTd/K8WVZLQxLEiXPdc CbKWGO9BGErSn3G2Jeh+1mBevLNLruQHGH3OzLxjSBBNIUm1jtVC2/mQqJsVp1lCuO3q2HnOBFuOe ee1MfduWiDzTiTOMQsdlsoSzRpQN9PO0lMThLySdyOv6HkbS+kn77PnocNCBPDXIbxwJcFRHdG0au JYPaUNktkRHv+oCpEwJvMRbIFmBygMOhkPKuoNzeDQ4OS5IV7qAZ4odKbRf525DB+duDogeNqUGl2 Y0adOedGYl8Z6f/I2TAjvwDcV3a57S3lny6A4G3AjEc0/pHUJvXCNWKsKBK+2jc9uN8WY0kp0Col6 B9LozgGg==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kptYT-0006kd-IQ; Thu, 17 Dec 2020 13:42:53 +0000 Date: Thu, 17 Dec 2020 13:42:53 +0000 From: Matthew Wilcox To: John Hubbard Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 18/25] btrfs: Use readahead_batch_length Message-ID: <20201217134253.GE15600@casper.infradead.org> References: <20201216182335.27227-1-willy@infradead.org> <20201216182335.27227-19-willy@infradead.org> <20201217121246.GD15600@casper.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201217121246.GD15600@casper.infradead.org> 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 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;