From nobody Sat Oct 25 08:55:13 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1520421491624904.9234374913352; Wed, 7 Mar 2018 03:18:11 -0800 (PST) Received: from localhost ([::1]:60823 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1etX5G-0003AL-M4 for importer@patchew.org; Wed, 07 Mar 2018 06:18:10 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59778) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1etWoP-000543-QG for qemu-devel@nongnu.org; Wed, 07 Mar 2018 06:00:51 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1etWoJ-0006Fu-Lq for qemu-devel@nongnu.org; Wed, 07 Mar 2018 06:00:45 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:44634 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1etWoJ-0006Fi-Gz for qemu-devel@nongnu.org; Wed, 07 Mar 2018 06:00:39 -0500 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 mx1.redhat.com (Postfix) with ESMTPS id 07F4F404084A for ; Wed, 7 Mar 2018 11:00:39 +0000 (UTC) Received: from secure.mitica (ovpn-116-34.ams2.redhat.com [10.36.116.34]) by smtp.corp.redhat.com (Postfix) with ESMTP id E46E5215CDA7; Wed, 7 Mar 2018 11:00:37 +0000 (UTC) From: Juan Quintela To: qemu-devel@nongnu.org Date: Wed, 7 Mar 2018 12:00:01 +0100 Message-Id: <20180307110010.2205-16-quintela@redhat.com> In-Reply-To: <20180307110010.2205-1-quintela@redhat.com> References: <20180307110010.2205-1-quintela@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Wed, 07 Mar 2018 11:00:39 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Wed, 07 Mar 2018 11:00:39 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'quintela@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH v10 15/24] migration: Synchronize send threads X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: lvivier@redhat.com, dgilbert@redhat.com, peterx@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" We synchronize all threads each RAM_SAVE_FLAG_EOS. Bitmap synchronizations don't happen inside a ram section, so we are safe about two channels trying to overwrite the same memory. Signed-off-by: Juan Quintela --- migration/ram.c | 38 +++++++++++++++++++++++++++++++++++++- migration/trace-events | 1 + 2 files changed, 38 insertions(+), 1 deletion(-) diff --git a/migration/ram.c b/migration/ram.c index e502be5dda..153c7560cb 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -403,6 +403,7 @@ struct MultiFDSendParams { QemuMutex mutex; bool running; bool quit; + bool sync; }; typedef struct MultiFDSendParams MultiFDSendParams; =20 @@ -410,6 +411,8 @@ struct { MultiFDSendParams *params; /* number of created threads */ int count; + /* syncs main thread and channels */ + QemuSemaphore sem_main; } *multifd_send_state; =20 static void terminate_multifd_send_threads(Error *errp) @@ -457,6 +460,7 @@ int multifd_save_cleanup(Error **errp) g_free(p->name); p->name =3D NULL; } + qemu_sem_destroy(&multifd_send_state->sem_main); g_free(multifd_send_state->params); multifd_send_state->params =3D NULL; g_free(multifd_send_state); @@ -464,18 +468,44 @@ int multifd_save_cleanup(Error **errp) return ret; } =20 +static void multifd_send_sync_main(void) +{ + int i; + + if (!migrate_use_multifd()) { + return; + } + for (i =3D 0; i < migrate_multifd_channels(); i++) { + MultiFDSendParams *p =3D &multifd_send_state->params[i]; + qemu_mutex_lock(&p->mutex); + p->sync =3D true; + qemu_mutex_unlock(&p->mutex); + qemu_sem_post(&p->sem); + } + for (i =3D 0; i < migrate_multifd_channels(); i++) { + qemu_sem_wait(&multifd_send_state->sem_main); + } + trace_multifd_send_sync_main(); +} + static void *multifd_send_thread(void *opaque) { MultiFDSendParams *p =3D opaque; =20 while (true) { + qemu_sem_wait(&p->sem); qemu_mutex_lock(&p->mutex); + if (p->sync) { + p->sync =3D false; + qemu_mutex_unlock(&p->mutex); + qemu_sem_post(&multifd_send_state->sem_main); + continue; + } if (p->quit) { qemu_mutex_unlock(&p->mutex); break; } qemu_mutex_unlock(&p->mutex); - qemu_sem_wait(&p->sem); } =20 return NULL; @@ -493,6 +523,8 @@ int multifd_save_setup(void) multifd_send_state =3D g_malloc0(sizeof(*multifd_send_state)); multifd_send_state->params =3D g_new0(MultiFDSendParams, thread_count); atomic_set(&multifd_send_state->count, 0); + qemu_sem_init(&multifd_send_state->sem_main, 0); + for (i =3D 0; i < thread_count; i++) { MultiFDSendParams *p =3D &multifd_send_state->params[i]; =20 @@ -507,6 +539,7 @@ int multifd_save_setup(void) =20 atomic_inc(&multifd_send_state->count); } + return 0; } =20 @@ -2283,6 +2316,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque) ram_control_before_iterate(f, RAM_CONTROL_SETUP); ram_control_after_iterate(f, RAM_CONTROL_SETUP); =20 + multifd_send_sync_main(); qemu_put_be64(f, RAM_SAVE_FLAG_EOS); =20 return 0; @@ -2351,6 +2385,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque) */ ram_control_after_iterate(f, RAM_CONTROL_ROUND); =20 + multifd_send_sync_main(); qemu_put_be64(f, RAM_SAVE_FLAG_EOS); ram_counters.transferred +=3D 8; =20 @@ -2403,6 +2438,7 @@ static int ram_save_complete(QEMUFile *f, void *opaqu= e) =20 rcu_read_unlock(); =20 + multifd_send_sync_main(); qemu_put_be64(f, RAM_SAVE_FLAG_EOS); =20 return 0; diff --git a/migration/trace-events b/migration/trace-events index 93961dea16..97b5ac564f 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -77,6 +77,7 @@ ram_load_postcopy_loop(uint64_t addr, int flags) "@%" PRI= x64 " %x" ram_postcopy_send_discard_bitmap(void) "" ram_save_page(const char *rbname, uint64_t offset, void *host) "%s: offset= : 0x%" PRIx64 " host: %p" ram_save_queue_pages(const char *rbname, size_t start, size_t len) "%s: st= art: 0x%zx len: 0x%zx" +multifd_send_sync_main(void) "" =20 # migration/migration.c await_return_path_close_on_source_close(void) "" --=20 2.14.3