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 E115FC43217 for ; Mon, 28 Nov 2022 10:08:00 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ozb0M-0002zF-8y; Mon, 28 Nov 2022 05:04:50 -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 1ozb0I-0002xs-QU for qemu-devel@nongnu.org; Mon, 28 Nov 2022 05:04:46 -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 1ozb0F-0002oR-On for qemu-devel@nongnu.org; Mon, 28 Nov 2022 05:04:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1669629881; 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=cCalpAo8q8HWr/VKqdAWp3A1qfoaNQII9k9mvBGAFvQ=; b=ctU3RWJ9l0lg2U1dxgY55Vw1DCMSZ35ipRRB042r3u9TKicwWIwEbzKV5+c/yW8lU1emNy WjHgR3rmxu3ecL37cchxeWjQGVLm21z7IlhLwDrYLDDerZ7EkXIeLLmZpW5AVXVfb7f+Ib SGinuwz5g33yhpmydbDGvlvsaGlKSSU= 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-292-YYZwcMndO-WO4hEfl7UBfw-1; Mon, 28 Nov 2022 05:04:38 -0500 X-MC-Unique: YYZwcMndO-WO4hEfl7UBfw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A01FE833A11; Mon, 28 Nov 2022 10:04:37 +0000 (UTC) Received: from secure.mitica (unknown [10.39.193.79]) by smtp.corp.redhat.com (Postfix) with ESMTP id 17BF62027063; Mon, 28 Nov 2022 10:04:35 +0000 (UTC) From: Juan Quintela To: qemu-devel@nongnu.org Cc: "Dr. David Alan Gilbert" , Juan Quintela , Eduardo Habkost , Eric Blake , Marcel Apfelbaum , Yanan Wang , Markus Armbruster , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Subject: [PATCH 06/11] multifd: Make flags field thread local Date: Mon, 28 Nov 2022 11:04:17 +0100 Message-Id: <20221128100422.13522-7-quintela@redhat.com> In-Reply-To: <20221128100422.13522-1-quintela@redhat.com> References: <20221128100422.13522-1-quintela@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=quintela@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 Use of flags with respect to locking was incensistant. For the sending side: - it was set to 0 with mutex held on the multifd channel. - MULTIFD_FLAG_SYNC was set with mutex held on the migration thread. - Everything else was done without the mutex held on the multifd channel. On the reception side, it is not used on the migration thread, only on the multifd channels threads. So we move it to the multifd channels thread only variables, and we introduce a new bool sync_needed on the send side to pass that information. Signed-off-by: Juan Quintela --- migration/multifd.h | 10 ++++++---- migration/multifd.c | 23 +++++++++++++---------- 2 files changed, 19 insertions(+), 14 deletions(-) diff --git a/migration/multifd.h b/migration/multifd.h index 36f899c56f..a67cefc0a2 100644 --- a/migration/multifd.h +++ b/migration/multifd.h @@ -98,12 +98,12 @@ typedef struct { bool running; /* should this thread finish */ bool quit; - /* multifd flags for each packet */ - uint32_t flags; /* global number of generated multifd packets */ uint64_t packet_num; /* How many bytes have we sent on the last packet */ uint64_t sent_bytes; + /* Do we need to do an iteration sync */ + bool sync_needed; /* thread has work to do */ int pending_job; /* array of pages to sent. @@ -117,6 +117,8 @@ typedef struct { /* pointer to the packet */ MultiFDPacket_t *packet; + /* multifd flags for each packet */ + uint32_t flags; /* size of the next packet that contains pages */ uint32_t next_packet_size; /* packets sent through this channel */ @@ -163,8 +165,6 @@ typedef struct { bool running; /* should this thread finish */ bool quit; - /* multifd flags for each packet */ - uint32_t flags; /* global number of generated multifd packets */ uint64_t packet_num; @@ -172,6 +172,8 @@ typedef struct { /* pointer to the packet */ MultiFDPacket_t *packet; + /* multifd flags for each packet */ + uint32_t flags; /* size of the next packet that contains pages */ uint32_t next_packet_size; /* packets sent through this channel */ diff --git a/migration/multifd.c b/migration/multifd.c index cd26b2fda9..77196a55b4 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -620,7 +620,7 @@ int multifd_send_sync_main(QEMUFile *f) } p->packet_num = multifd_send_state->packet_num++; - p->flags |= MULTIFD_FLAG_SYNC; + p->sync_needed = true; p->pending_job++; qemu_mutex_unlock(&p->mutex); qemu_sem_post(&p->sem); @@ -667,7 +667,11 @@ static void *multifd_send_thread(void *opaque) if (p->pending_job) { uint64_t packet_num = p->packet_num; - uint32_t flags = p->flags; + p->flags = 0; + if (p->sync_needed) { + p->flags |= MULTIFD_FLAG_SYNC; + p->sync_needed = false; + } p->normal_num = 0; if (use_zero_copy_send) { @@ -689,14 +693,13 @@ static void *multifd_send_thread(void *opaque) } } multifd_send_fill_packet(p); - p->flags = 0; p->num_packets++; p->total_normal_pages += p->normal_num; p->pages->num = 0; p->pages->block = NULL; qemu_mutex_unlock(&p->mutex); - trace_multifd_send(p->id, packet_num, p->normal_num, flags, + trace_multifd_send(p->id, packet_num, p->normal_num, p->flags, p->next_packet_size); if (use_zero_copy_send) { @@ -724,7 +727,7 @@ static void *multifd_send_thread(void *opaque) p->pending_job--; qemu_mutex_unlock(&p->mutex); - if (flags & MULTIFD_FLAG_SYNC) { + if (p->flags & MULTIFD_FLAG_SYNC) { qemu_sem_post(&p->sem_sync); } qemu_sem_post(&multifd_send_state->channels_ready); @@ -1099,7 +1102,7 @@ static void *multifd_recv_thread(void *opaque) rcu_register_thread(); while (true) { - uint32_t flags; + bool sync_needed = false; if (p->quit) { break; @@ -1121,11 +1124,11 @@ static void *multifd_recv_thread(void *opaque) break; } - flags = p->flags; + trace_multifd_recv(p->id, p->packet_num, p->normal_num, p->flags, + p->next_packet_size); + sync_needed = p->flags & MULTIFD_FLAG_SYNC; /* recv methods don't know how to handle the SYNC flag */ p->flags &= ~MULTIFD_FLAG_SYNC; - trace_multifd_recv(p->id, p->packet_num, p->normal_num, flags, - p->next_packet_size); p->num_packets++; p->total_normal_pages += p->normal_num; qemu_mutex_unlock(&p->mutex); @@ -1137,7 +1140,7 @@ static void *multifd_recv_thread(void *opaque) } } - if (flags & MULTIFD_FLAG_SYNC) { + if (sync_needed) { qemu_sem_post(&multifd_recv_state->sem_sync); qemu_sem_wait(&p->sem_sync); } -- 2.38.1