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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 55BB9C433F5 for ; Fri, 12 Nov 2021 10:58:09 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id E1B0D60F46 for ; Fri, 12 Nov 2021 10:58:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org E1B0D60F46 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:48858 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mlUG0-0001DW-35 for qemu-devel@archiver.kernel.org; Fri, 12 Nov 2021 05:58:08 -0500 Received: from eggs.gnu.org ([209.51.188.92]:35488) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mlUF4-0000W9-Lb for qemu-devel@nongnu.org; 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Fri, 12 Nov 2021 10:56:58 +0000 (UTC) Received: from redhat.com (unknown [10.33.36.12]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D932A5F4EC; Fri, 12 Nov 2021 10:56:49 +0000 (UTC) Date: Fri, 12 Nov 2021 10:56:46 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Leonardo Bras Subject: Re: [PATCH v5 1/6] QIOChannel: Add io_writev_zerocopy & io_flush_zerocopy callbacks Message-ID: References: <20211112051040.923746-1-leobras@redhat.com> <20211112051040.923746-2-leobras@redhat.com> MIME-Version: 1.0 In-Reply-To: <20211112051040.923746-2-leobras@redhat.com> User-Agent: Mutt/2.0.7 (2021-05-04) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.699, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: qemu-devel@nongnu.org, Markus Armbruster , Eric Blake , "Dr. David Alan Gilbert" , Juan Quintela Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, Nov 12, 2021 at 02:10:36AM -0300, Leonardo Bras wrote: > Adds io_writev_zerocopy and io_flush_zerocopy as optional callback to QIOChannelClass, > allowing the implementation of zerocopy writes by subclasses. > > How to use them: > - Write data using qio_channel_writev_zerocopy(), > - Wait write completion with qio_channel_flush_zerocopy(). > > Notes: > As some zerocopy implementations work asynchronously, it's > recommended to keep the write buffer untouched until the return of > qio_channel_flush_zerocopy(), to avoid the risk of sending an updated > buffer instead of the one at the write. > > As the new callbacks are optional, if a subclass does not implement them, then: > - io_writev_zerocopy will return -1, > - io_flush_zerocopy will return 0 without changing anything. > > Also, some functions like qio_channel_writev_full_all() were adapted to > receive a flag parameter. That allows shared code between zerocopy and > non-zerocopy writev. > > Signed-off-by: Leonardo Bras > --- > include/io/channel.h | 93 ++++++++++++++++++++++++++++++++++++++------ > io/channel.c | 65 +++++++++++++++++++++++++------ > 2 files changed, 135 insertions(+), 23 deletions(-) > > +/** > + * qio_channel_flush_zerocopy: > + * @ioc: the channel object > + * @errp: pointer to a NULL-initialized error object > + * > + * Will block until every packet queued with > + * qio_channel_writev_zerocopy() is sent, or return > + * in case of any error. > + * > + * Returns -1 if any error is found, 0 otherwise. Returns -1 if any error is found, 0 if all data was sent, or 1 if all data was sent but at least some was copied. > + * If not implemented, acts as a no-op, and returns 0. > + */ > + > +int qio_channel_flush_zerocopy(QIOChannel *ioc, > + Error **errp); Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|