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[2620:137:e000::1:20]) by mx.google.com with ESMTP id h6-20020a4a6b46000000b00324bb47350fsi1207726oof.47.2022.03.23.14.33.01; Wed, 23 Mar 2022 14:33:16 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-nfs-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=casper.20170209 header.b=AALIGi39; spf=pass (google.com: domain of linux-nfs-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-nfs-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241135AbiCWVdt (ORCPT + 99 others); Wed, 23 Mar 2022 17:33:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38738 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240867AbiCWVds (ORCPT ); Wed, 23 Mar 2022 17:33:48 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1EFB33EF0C; Wed, 23 Mar 2022 14:32:18 -0700 (PDT) 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=mYNJfGGSVaocDlmcw7Y6SzRfFy2YudcedELxKPfKos4=; b=AALIGi39gaeafdIUdimblw8VAP GcF2M2hi3z/FkOGSIrNoAIvW4v4ViL+ZEGcUkHD7Sw5lTir86cvGWJOBSouooJ7I/ABC2xgHVZqAh PYKRde2/ygfGxXHxCa1SJTX8On5h7jhfp5BPDbu3fSE0Aczm1ro+lWQZxn2gS6N1ufFTG6+31ZDir iwDqMGs5JBl+ZgMEV14T7SfD4XE9g2O7cn68Rb/r2nScpALp5TloWG5sbOm2xm8o3LjFPeJurqgvO fQU35onhWq+GAp0Xxz1V8aeurBAsJbffkof+iCNluYLS0klgtGkojzu0aLcYido3SBV8HD5ieMr26 5G3hdpMg==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nX8aU-00CrO3-AE; Wed, 23 Mar 2022 21:32:14 +0000 Date: Wed, 23 Mar 2022 21:32:14 +0000 From: Matthew Wilcox To: Thiago Becker Cc: linux-nfs@vger.kernel.org, steved@redhat.com, trond.myklebust@hammerspace.com, anna.schumaker@netapp.com, kolga@netapp.com, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH RFC v3 0/6] Intruduce nfsrahead Message-ID: References: <20220323201841.4166549-1-tbecker@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220323201841.4166549-1-tbecker@redhat.com> X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Wed, Mar 23, 2022 at 05:18:35PM -0300, Thiago Becker wrote: > Recent changes in the linux kernel caused NFS readahead to default to > 128 from the previous default of 15 * rsize. This causes performance > penalties to some read-heavy workloads, which can be fixed by > tuning the readahead for that given mount. Which recent changes? Something in NFS or something in the VFS/MM? Did you even think about asking a wider audience than the NFS mailing list? I only happened to notice this while I was looking for something else, otherwise I would never have seen it. The responses from other people to your patches were right; you're trying to do this all wrong. Let's start out with a bug report instead of a solution. What changed and when?