From patchwork Wed Jan 31 10:31:09 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Xu X-Patchwork-Id: 13539152 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 1F206C4828E for ; Wed, 31 Jan 2024 10:34:50 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rV7tI-0006LP-M2; Wed, 31 Jan 2024 05:32:25 -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 1rV7tF-0006GQ-AS for qemu-devel@nongnu.org; Wed, 31 Jan 2024 05:32:21 -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 1rV7tD-0005ht-KY for qemu-devel@nongnu.org; Wed, 31 Jan 2024 05:32:21 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1706697139; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HItvWTBtuA8FYgr9X67VP5r885DjM/aVflysOooJ0tY=; b=ZFmWyE7YhMjPQtedeDs59kyUWrUgSMAFByjmcuZNKRnNaOjr0b2leIz45LHWmYNT94/5io awZilmhironf6NMC2gPxDodAaLAes0bfR8+9DrDcQFDEdk0I543LscesLKlHNomVy1STPR J6uZF3hnclK8p75piJoJdu3erFngJl4= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-284-l-4GCL5eNbWGcMqx_dvLLw-1; Wed, 31 Jan 2024 05:32:15 -0500 X-MC-Unique: l-4GCL5eNbWGcMqx_dvLLw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B2E5A8B3960; Wed, 31 Jan 2024 10:32:14 +0000 (UTC) Received: from x1n.redhat.com (unknown [10.72.116.11]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9BF31107BD; Wed, 31 Jan 2024 10:32:10 +0000 (UTC) From: peterx@redhat.com To: qemu-devel@nongnu.org Cc: Bryan Zhang , Prasad Pandit , Fabiano Rosas , peterx@redhat.com, Yuan Liu , Avihai Horon , Hao Xiang Subject: [PATCH 12/14] migration/multifd: multifd_send_prepare_header() Date: Wed, 31 Jan 2024 18:31:09 +0800 Message-ID: <20240131103111.306523-13-peterx@redhat.com> In-Reply-To: <20240131103111.306523-1-peterx@redhat.com> References: <20240131103111.306523-1-peterx@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.133.124; envelope-from=peterx@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.292, 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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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 From: Peter Xu Introduce a helper multifd_send_prepare_header() to setup the header packet for multifd sender. It's fine to setup the IOV[0] _before_ send_prepare() because the packet buffer is already ready, even if the content is to be filled in. With this helper, we can already slightly clean up the zero copy path. Note that I explicitly put it into multifd.h, because I want it inlined directly into multifd*.c where necessary later. Signed-off-by: Peter Xu Reviewed-by: Fabiano Rosas --- migration/multifd.h | 8 ++++++++ migration/multifd.c | 16 ++++++++-------- 2 files changed, 16 insertions(+), 8 deletions(-) diff --git a/migration/multifd.h b/migration/multifd.h index 2e4ad0dc56..4ec005f53f 100644 --- a/migration/multifd.h +++ b/migration/multifd.h @@ -209,5 +209,13 @@ typedef struct { void multifd_register_ops(int method, MultiFDMethods *ops); +static inline void multifd_send_prepare_header(MultiFDSendParams *p) +{ + p->iov[0].iov_len = p->packet_len; + p->iov[0].iov_base = p->packet; + p->iovs_num++; +} + + #endif diff --git a/migration/multifd.c b/migration/multifd.c index 8d4b80f365..1b0035787e 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -707,10 +707,14 @@ static void *multifd_send_thread(void *opaque) if (p->pending_job) { MultiFDPages_t *pages = p->pages; - if (use_zero_copy_send) { - p->iovs_num = 0; - } else { - p->iovs_num = 1; + p->iovs_num = 0; + + if (!use_zero_copy_send) { + /* + * Only !zero_copy needs the header in IOV; zerocopy will + * send it separately. + */ + multifd_send_prepare_header(p); } assert(pages->num); @@ -730,10 +734,6 @@ static void *multifd_send_thread(void *opaque) if (ret != 0) { break; } - } else { - /* Send header using the same writev call */ - p->iov[0].iov_len = p->packet_len; - p->iov[0].iov_base = p->packet; } ret = qio_channel_writev_full_all(p->c, p->iov, p->iovs_num, NULL,