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=-0.6 required=3.0 tests=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 2113DC33CA9 for ; Tue, 14 Jan 2020 00:14:24 +0000 (UTC) Received: from lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D38BA2084D; Tue, 14 Jan 2020 00:14:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=sourceforge.net header.i=@sourceforge.net header.b="A3WDtL2e"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=sf.net header.i=@sf.net header.b="RROlYOJo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D38BA2084D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=mit.edu Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linux-f2fs-devel-bounces@lists.sourceforge.net Received: from [127.0.0.1] (helo=sfs-ml-1.v29.lw.sourceforge.com) by sfs-ml-1.v29.lw.sourceforge.com with esmtp (Exim 4.90_1) (envelope-from ) id 1ir9qh-0005Nk-3C; Tue, 14 Jan 2020 00:14:23 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-1.v29.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ir9qf-0005NV-Kw for linux-f2fs-devel@lists.sourceforge.net; Tue, 14 Jan 2020 00:14:21 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; 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:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=KM2l9QyIZRoILZJtRs+biVQwMOKhP43uRtd2/GEe+bc=; b=A3WDtL2e5ber8GU8rBEHyCR6uH l1PmhpwqVtQDyZDzDwN2gRgpQmmWbF+/OluRN9MPIESsbNYbzZjZuQXgNoo+nRkOiHtpzt7zLBPhC D2JkAprp5B+kfkfz9M8028VY6jUkn8w/915atLPu4o6iIAzaxqc23ASNgj200k08cp4g=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; 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:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=KM2l9QyIZRoILZJtRs+biVQwMOKhP43uRtd2/GEe+bc=; b=RROlYOJom/s9zsdVwiYrLN52Kn ThvtGA1ee2xrNdUkjlWUfiwVjx15l+HSTOh3ylOnBTUVyaIlIJAfCIJBSfACYYQzs/nG4aA6yFkeB eY4d+KySb2HH+xK426pFRK2Ta6BtVx5+/CqfcFc4oDTdbK4Tb9/0IT21ozpnbGAUgFlY=; Received: from outgoing-auth-1.mit.edu ([18.9.28.11] helo=outgoing.mit.edu) by sfi-mx-3.v28.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.92.2) id 1ir9qe-001djC-2A for linux-f2fs-devel@lists.sourceforge.net; Tue, 14 Jan 2020 00:14:21 +0000 Received: from callcc.thunk.org (guestnat-104-133-0-111.corp.google.com [104.133.0.111] (may be forged)) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 00E0E7YN032266 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 13 Jan 2020 19:14:08 -0500 Received: by callcc.thunk.org (Postfix, from userid 15806) id AB74C4207DF; Mon, 13 Jan 2020 19:14:07 -0500 (EST) Date: Mon, 13 Jan 2020 19:14:07 -0500 From: "Theodore Y. Ts'o" To: Eric Biggers Message-ID: <20200114001407.GO76141@mit.edu> References: <20200106205533.137005-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200106205533.137005-1-ebiggers@kernel.org> X-Headers-End: 1ir9qe-001djC-2A Subject: Re: [f2fs-dev] [PATCH v2] fs-verity: implement readahead of Merkle tree pages X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-fsdevel@vger.kernel.org, linux-fscrypt@vger.kernel.org, linux-ext4@vger.kernel.org, Victor Hsieh , linux-f2fs-devel@lists.sourceforge.net Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net On Mon, Jan 06, 2020 at 12:55:33PM -0800, Eric Biggers wrote: > From: Eric Biggers > > When fs-verity verifies data pages, currently it reads each Merkle tree > page synchronously using read_mapping_page(). > > Therefore, when the Merkle tree pages aren't already cached, fs-verity > causes an extra 4 KiB I/O request for every 512 KiB of data (assuming > that the Merkle tree uses SHA-256 and 4 KiB blocks). This results in > more I/O requests and performance loss than is strictly necessary. > > Therefore, implement readahead of the Merkle tree pages. Looks good. Feel free to add: Reviewed-by: Theodore Ts'o (for the ext4 and fs/verity bits) _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel