From patchwork Fri Feb 22 03:14:11 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Peter Xu X-Patchwork-Id: 1046555 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 445Gh90TcMz9s8m for ; Fri, 22 Feb 2019 14:16:09 +1100 (AEDT) Received: from localhost ([127.0.0.1]:43409 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gx1Jg-0001S0-B9 for incoming@patchwork.ozlabs.org; Thu, 21 Feb 2019 22:16:00 -0500 Received: from eggs.gnu.org ([209.51.188.92]:40011) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gx1Ix-0001Pn-AL for qemu-devel@nongnu.org; Thu, 21 Feb 2019 22:15:16 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gx1Iv-0000ru-Al for qemu-devel@nongnu.org; Thu, 21 Feb 2019 22:15:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:53634) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gx1Ir-00009h-A4 for qemu-devel@nongnu.org; Thu, 21 Feb 2019 22:15:11 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6E6053688B for ; Fri, 22 Feb 2019 03:14:37 +0000 (UTC) Received: from xz-x1.redhat.com (ovpn-12-57.pek2.redhat.com [10.72.12.57]) by smtp.corp.redhat.com (Postfix) with ESMTP id DFCEF5D9D4; Fri, 22 Feb 2019 03:14:33 +0000 (UTC) From: Peter Xu To: qemu-devel@nongnu.org Date: Fri, 22 Feb 2019 11:14:11 +0800 Message-Id: <20190222031413.20250-3-peterx@redhat.com> In-Reply-To: <20190222031413.20250-1-peterx@redhat.com> References: <20190222031413.20250-1-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Fri, 22 Feb 2019 03:14:37 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 2/4] iothread: create the gcontext onconditionally 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: Paolo Bonzini , peterx@redhat.com, Stefan Hajnoczi , =?utf-8?q?Marc-Andr=C3=A9_Lureau?= Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" In existing code we create the gcontext dynamically at the first access of the gcontext from caller. That can bring some complexity and potential races during using iothread. Since the context itself is not that big a resource, and we won't have millions of iothread, let's simply create the gcontext unconditionally. This will also be a preparation work further to move the thread context push operation earlier than before (now it's only pushed right before we want to start running the gmainloop). Removing the g_once since it's not necessary, while introducing a new run_gcontext boolean to show whether we want to run the gcontext. Signed-off-by: Peter Xu Reviewed-by: Marc-André Lureau --- include/sysemu/iothread.h | 2 +- iothread.c | 43 +++++++++++++++++++-------------------- 2 files changed, 22 insertions(+), 23 deletions(-) diff --git a/include/sysemu/iothread.h b/include/sysemu/iothread.h index 50411ba54a..5f6240d5cb 100644 --- a/include/sysemu/iothread.h +++ b/include/sysemu/iothread.h @@ -24,9 +24,9 @@ typedef struct { QemuThread thread; AioContext *ctx; + bool run_gcontext; /* whether we should run gcontext */ GMainContext *worker_context; GMainLoop *main_loop; - GOnce once; QemuSemaphore init_done_sem; /* is thread init done? */ bool stopping; /* has iothread_stop() been called? */ bool running; /* should iothread_run() continue? */ diff --git a/iothread.c b/iothread.c index 6e297e9ef1..6fa87876e0 100644 --- a/iothread.c +++ b/iothread.c @@ -65,7 +65,7 @@ static void *iothread_run(void *opaque) * We must check the running state again in case it was * changed in previous aio_poll() */ - if (iothread->running && atomic_read(&iothread->worker_context)) { + if (iothread->running && atomic_read(&iothread->run_gcontext)) { GMainLoop *loop; g_main_context_push_thread_default(iothread->worker_context); @@ -114,6 +114,8 @@ static void iothread_instance_init(Object *obj) iothread->poll_max_ns = IOTHREAD_POLL_MAX_NS_DEFAULT; iothread->thread_id = -1; qemu_sem_init(&iothread->init_done_sem, 0); + /* By default, we don't run gcontext */ + atomic_set(&iothread->run_gcontext, 0); } static void iothread_instance_finalize(Object *obj) @@ -143,6 +145,16 @@ static void iothread_instance_finalize(Object *obj) qemu_sem_destroy(&iothread->init_done_sem); } +static void iothread_init_gcontext(IOThread *iothread) +{ + GSource *source; + + iothread->worker_context = g_main_context_new(); + source = aio_get_g_source(iothread_get_aio_context(iothread)); + g_source_attach(source, iothread->worker_context); + g_source_unref(source); +} + static void iothread_complete(UserCreatable *obj, Error **errp) { Error *local_error = NULL; @@ -157,6 +169,12 @@ static void iothread_complete(UserCreatable *obj, Error **errp) return; } + /* + * Init one GMainContext for the iothread unconditionally, even if + * it's not used + */ + iothread_init_gcontext(iothread); + aio_context_set_poll_params(iothread->ctx, iothread->poll_max_ns, iothread->poll_grow, @@ -169,8 +187,6 @@ static void iothread_complete(UserCreatable *obj, Error **errp) return; } - iothread->once = (GOnce) G_ONCE_INIT; - /* This assumes we are called from a thread with useful CPU affinity for us * to inherit. */ @@ -333,27 +349,10 @@ IOThreadInfoList *qmp_query_iothreads(Error **errp) return head; } -static gpointer iothread_g_main_context_init(gpointer opaque) -{ - AioContext *ctx; - IOThread *iothread = opaque; - GSource *source; - - iothread->worker_context = g_main_context_new(); - - ctx = iothread_get_aio_context(iothread); - source = aio_get_g_source(ctx); - g_source_attach(source, iothread->worker_context); - g_source_unref(source); - - aio_notify(iothread->ctx); - return NULL; -} - GMainContext *iothread_get_g_main_context(IOThread *iothread) { - g_once(&iothread->once, iothread_g_main_context_init, iothread); - + atomic_set(&iothread->run_gcontext, 1); + aio_notify(iothread->ctx); return iothread->worker_context; } From patchwork Fri Feb 22 03:14:12 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Peter Xu X-Patchwork-Id: 1046553 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 445Ggk4S4Rz9s9L for ; Fri, 22 Feb 2019 14:15:46 +1100 (AEDT) Received: from localhost ([127.0.0.1]:43393 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gx1JQ-0001JI-A3 for incoming@patchwork.ozlabs.org; Thu, 21 Feb 2019 22:15:44 -0500 Received: from eggs.gnu.org ([209.51.188.92]:39939) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gx1Im-0001IX-6Z for qemu-devel@nongnu.org; Thu, 21 Feb 2019 22:15:04 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gx1Ik-0000hl-Jl for qemu-devel@nongnu.org; Thu, 21 Feb 2019 22:15:03 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57158) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gx1Ij-0000M3-Vj for qemu-devel@nongnu.org; Thu, 21 Feb 2019 22:15:02 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8C0826699D for ; Fri, 22 Feb 2019 03:14:48 +0000 (UTC) Received: from xz-x1.redhat.com (ovpn-12-57.pek2.redhat.com [10.72.12.57]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1C7495D9D4; Fri, 22 Feb 2019 03:14:37 +0000 (UTC) From: Peter Xu To: qemu-devel@nongnu.org Date: Fri, 22 Feb 2019 11:14:12 +0800 Message-Id: <20190222031413.20250-4-peterx@redhat.com> In-Reply-To: <20190222031413.20250-1-peterx@redhat.com> References: <20190222031413.20250-1-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Fri, 22 Feb 2019 03:14:48 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 3/4] iothread: create main loop unconditionally 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: Paolo Bonzini , peterx@redhat.com, Stefan Hajnoczi , =?utf-8?q?Marc-Andr=C3=A9_Lureau?= Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Since we've have the gcontext always there, create the main loop altogether. The iothread_run() is even cleaner. Signed-off-by: Peter Xu Reviewed-by: Marc-André Lureau --- iothread.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/iothread.c b/iothread.c index 6fa87876e0..9abdbace66 100644 --- a/iothread.c +++ b/iothread.c @@ -66,17 +66,8 @@ static void *iothread_run(void *opaque) * changed in previous aio_poll() */ if (iothread->running && atomic_read(&iothread->run_gcontext)) { - GMainLoop *loop; - g_main_context_push_thread_default(iothread->worker_context); - iothread->main_loop = - g_main_loop_new(iothread->worker_context, TRUE); - loop = iothread->main_loop; - g_main_loop_run(iothread->main_loop); - iothread->main_loop = NULL; - g_main_loop_unref(loop); - g_main_context_pop_thread_default(iothread->worker_context); } } @@ -141,6 +132,8 @@ static void iothread_instance_finalize(Object *obj) if (iothread->worker_context) { g_main_context_unref(iothread->worker_context); iothread->worker_context = NULL; + g_main_loop_unref(iothread->main_loop); + iothread->main_loop = NULL; } qemu_sem_destroy(&iothread->init_done_sem); } @@ -153,6 +146,7 @@ static void iothread_init_gcontext(IOThread *iothread) source = aio_get_g_source(iothread_get_aio_context(iothread)); g_source_attach(source, iothread->worker_context); g_source_unref(source); + iothread->main_loop = g_main_loop_new(iothread->worker_context, TRUE); } static void iothread_complete(UserCreatable *obj, Error **errp) From patchwork Fri Feb 22 03:14:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Xu X-Patchwork-Id: 1046557 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 445Gkm4w6Lz9s9T for ; Fri, 22 Feb 2019 14:18:24 +1100 (AEDT) Received: from localhost ([127.0.0.1]:43432 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gx1Ly-0003C4-KN for incoming@patchwork.ozlabs.org; Thu, 21 Feb 2019 22:18:22 -0500 Received: from eggs.gnu.org ([209.51.188.92]:40396) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gx1Ju-0002Az-09 for qemu-devel@nongnu.org; Thu, 21 Feb 2019 22:16:14 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gx1Jt-0002JW-1s for qemu-devel@nongnu.org; Thu, 21 Feb 2019 22:16:13 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57174) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gx1Js-0000Pi-OD for qemu-devel@nongnu.org; Thu, 21 Feb 2019 22:16:12 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A998D99CE8 for ; Fri, 22 Feb 2019 03:14:52 +0000 (UTC) Received: from xz-x1.redhat.com (ovpn-12-57.pek2.redhat.com [10.72.12.57]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2909A5D9D4; Fri, 22 Feb 2019 03:14:48 +0000 (UTC) From: Peter Xu To: qemu-devel@nongnu.org Date: Fri, 22 Feb 2019 11:14:13 +0800 Message-Id: <20190222031413.20250-5-peterx@redhat.com> In-Reply-To: <20190222031413.20250-1-peterx@redhat.com> References: <20190222031413.20250-1-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Fri, 22 Feb 2019 03:14:52 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 4/4] iothread: push gcontext earlier in the thread_fn 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: Paolo Bonzini , peterx@redhat.com, Stefan Hajnoczi , =?utf-8?q?Marc-Andr=C3=A9_Lureau?= Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" We were pushing the context until right before running the gmainloop. Now since we have everything unconditionally, we can move this earlier. One benefit is that now it's done even before init_done_sem, so as long as the iothread user calls iothread_create() and completes, we know that the thread stack is ready. Signed-off-by: Peter Xu --- iothread.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/iothread.c b/iothread.c index 9abdbace66..7b7cba5d04 100644 --- a/iothread.c +++ b/iothread.c @@ -53,7 +53,7 @@ static void *iothread_run(void *opaque) IOThread *iothread = opaque; rcu_register_thread(); - + g_main_context_push_thread_default(iothread->worker_context); my_iothread = iothread; iothread->thread_id = qemu_get_thread_id(); qemu_sem_post(&iothread->init_done_sem); @@ -66,12 +66,11 @@ static void *iothread_run(void *opaque) * changed in previous aio_poll() */ if (iothread->running && atomic_read(&iothread->run_gcontext)) { - g_main_context_push_thread_default(iothread->worker_context); g_main_loop_run(iothread->main_loop); - g_main_context_pop_thread_default(iothread->worker_context); } } + g_main_context_pop_thread_default(iothread->worker_context); rcu_unregister_thread(); return NULL; }