From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41030) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WGrNk-0003JI-2v for qemu-devel@nongnu.org; Fri, 21 Feb 2014 09:47:22 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WGrNd-0006gx-PI for qemu-devel@nongnu.org; Fri, 21 Feb 2014 09:47:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:14071) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WGrNd-0006ge-HB for qemu-devel@nongnu.org; Fri, 21 Feb 2014 09:47:09 -0500 From: Stefan Hajnoczi Date: Fri, 21 Feb 2014 15:46:55 +0100 Message-Id: <1392994018-7786-4-git-send-email-stefanha@redhat.com> In-Reply-To: <1392994018-7786-1-git-send-email-stefanha@redhat.com> References: <1392994018-7786-1-git-send-email-stefanha@redhat.com> Subject: [Qemu-devel] [PATCH v4 3/6] iothread: add I/O thread object List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , Paolo Bonzini , Fam Zheng , Michael Roth This is a stand-in for Michael Roth's QContext. I expect this to be replaced once QContext is completed. The IOThread object is an AioContext event loop thread. This patch adds the concept of multiple event loop threads, allowing users to define them. When SMP guests run on SMP hosts it makes sense to instantiate multiple IOThreads. This spreads event loop processing across multiple cores. Note that additional patches are required to actually bind a device to an IOThread. Signed-off-by: Stefan Hajnoczi --- Makefile.objs | 1 + include/sysemu/iothread.h | 30 +++++++++++ iothread.c | 123 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 154 insertions(+) create mode 100644 include/sysemu/iothread.h create mode 100644 iothread.c diff --git a/Makefile.objs b/Makefile.objs index ac1d0e1..e24b89c 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -42,6 +42,7 @@ libcacard-y += libcacard/vcardt.o ifeq ($(CONFIG_SOFTMMU),y) common-obj-y = $(block-obj-y) blockdev.o blockdev-nbd.o block/ +common-obj-y += iothread.o common-obj-y += net/ common-obj-y += qdev-monitor.o device-hotplug.o common-obj-$(CONFIG_WIN32) += os-win32.o diff --git a/include/sysemu/iothread.h b/include/sysemu/iothread.h new file mode 100644 index 0000000..a32214a --- /dev/null +++ b/include/sysemu/iothread.h @@ -0,0 +1,30 @@ +/* + * Event loop thread + * + * Copyright Red Hat Inc., 2013 + * + * Authors: + * Stefan Hajnoczi + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + */ + +#ifndef IOTHREAD_H +#define IOTHREAD_H + +#include "block/aio.h" + +#define TYPE_IOTHREAD "iothread" + +typedef struct IOThread IOThread; + +#define IOTHREAD(obj) \ + OBJECT_CHECK(IOThread, obj, TYPE_IOTHREAD) + +IOThread *iothread_find(const char *id); +char *iothread_get_id(IOThread *iothread); +AioContext *iothread_get_aio_context(IOThread *iothread); + +#endif /* IOTHREAD_H */ diff --git a/iothread.c b/iothread.c new file mode 100644 index 0000000..033de7f --- /dev/null +++ b/iothread.c @@ -0,0 +1,123 @@ +/* + * Event loop thread + * + * Copyright Red Hat Inc., 2013 + * + * Authors: + * Stefan Hajnoczi + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + */ + +#include "qom/object.h" +#include "qom/object_interfaces.h" +#include "qemu/module.h" +#include "qemu/thread.h" +#include "block/aio.h" +#include "sysemu/iothread.h" + +#define IOTHREADS_PATH "/objects" + +typedef ObjectClass IOThreadClass; +struct IOThread { + Object parent; + QemuThread thread; + AioContext *ctx; + bool stopping; +}; + +#define IOTHREAD_GET_CLASS(obj) \ + OBJECT_GET_CLASS(IOThreadClass, obj, TYPE_IOTHREAD) +#define IOTHREAD_CLASS(klass) \ + OBJECT_CLASS_CHECK(IOThreadClass, klass, TYPE_IOTHREAD) + +static void *iothread_run(void *opaque) +{ + IOThread *iothread = opaque; + + while (!iothread->stopping) { + aio_context_acquire(iothread->ctx); + while (!iothread->stopping && aio_poll(iothread->ctx, true)) { + /* Progress was made, keep going */ + } + aio_context_release(iothread->ctx); + } + return NULL; +} + +static void iothread_instance_finalize(Object *obj) +{ + IOThread *iothread = IOTHREAD(obj); + + iothread->stopping = true; + aio_notify(iothread->ctx); + qemu_thread_join(&iothread->thread); + aio_context_unref(iothread->ctx); +} + +static void iothread_complete(UserCreatable *obj, Error **errp) +{ + IOThread *iothread = IOTHREAD(obj); + + iothread->stopping = false; + iothread->ctx = aio_context_new(); + + /* This assumes we are called from a thread with useful CPU affinity for us + * to inherit. + */ + qemu_thread_create(&iothread->thread, iothread_run, + iothread, QEMU_THREAD_JOINABLE); +} + +static void iothread_class_init(ObjectClass *klass, void *class_data) +{ + UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass); + ucc->complete = iothread_complete; +} + +static const TypeInfo iothread_info = { + .name = TYPE_IOTHREAD, + .parent = TYPE_OBJECT, + .class_init = iothread_class_init, + .instance_size = sizeof(IOThread), + .instance_finalize = iothread_instance_finalize, + .interfaces = (InterfaceInfo[]) { + {TYPE_USER_CREATABLE}, + {} + }, +}; + +static void iothread_register_types(void) +{ + type_register_static(&iothread_info); +} + +type_init(iothread_register_types) + +IOThread *iothread_find(const char *id) +{ + Object *container = container_get(object_get_root(), IOTHREADS_PATH); + Object *child; + + child = object_property_get_link(container, id, NULL); + if (!child) { + return NULL; + } + return (IOThread *)object_dynamic_cast(child, TYPE_IOTHREAD); +} + +char *iothread_get_id(IOThread *iothread) +{ + /* The last path component is the identifier */ + char *path = object_get_canonical_path(OBJECT(iothread)); + char *id = g_strdup(&path[sizeof(IOTHREADS_PATH)]); + g_free(path); + return id; +} + +AioContext *iothread_get_aio_context(IOThread *iothread) +{ + return iothread->ctx; +} -- 1.8.5.3