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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3177EC54EAA for ; Fri, 27 Jan 2023 23:25:10 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pLY5J-00084u-RJ; Fri, 27 Jan 2023 18:24:41 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pLY5H-000847-KR for qemu-devel@nongnu.org; Fri, 27 Jan 2023 18:24:39 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pLY5E-000108-JP for qemu-devel@nongnu.org; Fri, 27 Jan 2023 18:24:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1674861875; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=DAjFcAghqeqmLbhNjEYbBwcM4UOMuG5fHUiGn7ewlyc=; b=K2lSF5YrbSdV4ZxhVmJuf1ZwdApoyta2MpfoirkRmOmAAHqdbnsE3NT2R/quxkcvmSVN26 oBkjr6in5X75ZjEDeL9ecjf79TrMjYn+wzKIXQlgBs/3qpktx7YPnBW8A1hQ9OVFC7UXyi LfwaoQgdL1z7W/reGkKL3RBad9kanuk= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-232-5I95SaPYNdi-uj5WlPFPkQ-1; Fri, 27 Jan 2023 18:24:33 -0500 X-MC-Unique: 5I95SaPYNdi-uj5WlPFPkQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 0D81E802BF5; Fri, 27 Jan 2023 23:24:33 +0000 (UTC) Received: from redhat.com (unknown [10.2.17.173]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 63CEE2166B26; Fri, 27 Jan 2023 23:24:32 +0000 (UTC) Date: Fri, 27 Jan 2023 17:24:30 -0600 From: Eric Blake To: Stefan Hajnoczi Cc: qemu-devel@nongnu.org, Fam Zheng , Kevin Wolf , Hanna Reitz , qemu-block@nongnu.org, Fiona Ebner Subject: Re: [PATCH 3/4] qemu-io: add -r option to register I/O buffer Message-ID: <20230127232430.zy7x7wq2dvb3g3y2@redhat.com> References: <20230126201401.348845-1-stefanha@redhat.com> <20230126201401.348845-4-stefanha@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230126201401.348845-4-stefanha@redhat.com> User-Agent: NeoMutt/20220429 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 Received-SPF: pass client-ip=170.10.133.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Thu, Jan 26, 2023 at 03:14:00PM -0500, Stefan Hajnoczi wrote: > The blk_register_buf() API is an optimization hint that allows some > block drivers to avoid I/O buffer housekeeping or bounce buffers. > > Add an -r option to register the I/O buffer so that qemu-io can be used > to test the blk_register_buf() API. The next commit will add a test that > uses the new option. > > Signed-off-by: Stefan Hajnoczi > --- > qemu-io-cmds.c | 149 ++++++++++++++++++++++++++++++++++--------------- > 1 file changed, 103 insertions(+), 46 deletions(-) > > static void *qemu_io_alloc_from_file(BlockBackend *blk, size_t len, > - const char *file_name) > + const char *file_name, bool register_buf) > { > char *buf, *buf_origin; > FILE *f = fopen(file_name, "r"); > @@ -414,6 +423,10 @@ static void *qemu_io_alloc_from_file(BlockBackend *blk, size_t len, > fclose(f); > f = NULL; > > + if (register_buf) { > + blk_register_buf(blk, buf_origin, len, &error_abort); > + } Why is this conditionally true... > + > if (len > pattern_len) { > len -= pattern_len; > buf += pattern_len; > @@ -431,7 +444,7 @@ static void *qemu_io_alloc_from_file(BlockBackend *blk, size_t len, > return buf_origin; > > error: > - qemu_io_free(buf_origin); > + qemu_io_free(blk, buf_origin, len, false); ...but cleanup unconditionally false? > @@ -719,6 +732,7 @@ static void read_help(void) > " -p, -- ignored for backwards compatibility\n" > " -P, -- use a pattern to verify read data\n" > " -q, -- quiet mode, do not show I/O statistics\n" > +" -r, -- register I/O buffer\n" > " -s, -- start offset for pattern verification (only with -P)\n" > " -v, -- dump buffer to standard output\n" Here we have kept more or less alphabetical... > @@ -909,6 +932,7 @@ static void readv_help(void) > " -P, -- use a pattern to verify read data\n" > " -v, -- dump buffer to standard output\n" > " -q, -- quiet mode, do not show I/O statistics\n" > +" -r, -- register I/O buffer\n" ...here we have not. While it's pre-existing, would it be worth touching up while you're here? > @@ -1455,6 +1503,7 @@ static void aio_read_help(void) > " -i, -- treat request as invalid, for exercising stats\n" > " -v, -- dump buffer to standard output\n" > " -q, -- quiet mode, do not show I/O statistics\n" > +" -r, -- register I/O buffer\n" Another pre-existing spot. Overall makes sense to me. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org