[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH for-2.5] virtio-9p: use QEMU thread pool
From: |
Greg Kurz |
Subject: |
Re: [Qemu-devel] [PATCH for-2.5] virtio-9p: use QEMU thread pool |
Date: |
Fri, 27 Nov 2015 13:42:46 +0100 |
On Fri, 27 Nov 2015 12:43:06 +0100
Paolo Bonzini <address@hidden> wrote:
> The QEMU thread pool already has a mechanism to invoke callbacks in the main
> thread. It does not need an EventNotifier and it is more efficient too.
> Use it instead of GAsyncQueue + GThreadPool + glue.
>
> As a side effect, it silences Coverity's complaint about an unchecked
> return value for event_notifier_init.
>
And it makes the code a lot nicer too !
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---
I have just one minor remark in hw/9pfs/virtio-9p-coth.h but anyway:
Reviewed-by: Greg Kurz <address@hidden>
Tested-by: Greg Kurz <address@hidden>
> hw/9pfs/virtio-9p-coth.c | 79
> +++++++++++-----------------------------------
> hw/9pfs/virtio-9p-coth.h | 9 +-----
> hw/9pfs/virtio-9p-device.c | 4 ---
> 3 files changed, 20 insertions(+), 72 deletions(-)
>
> diff --git a/hw/9pfs/virtio-9p-coth.c b/hw/9pfs/virtio-9p-coth.c
> index 5057f8d..fb6e8f8 100644
> --- a/hw/9pfs/virtio-9p-coth.c
> +++ b/hw/9pfs/virtio-9p-coth.c
> @@ -12,71 +12,30 @@
> *
> */
>
> -#include "fsdev/qemu-fsdev.h"
> -#include "qemu/thread.h"
> -#include "qemu/event_notifier.h"
> +#include "qemu-common.h"
> +#include "block/thread-pool.h"
> #include "qemu/coroutine.h"
> +#include "qemu/main-loop.h"
> #include "virtio-9p-coth.h"
>
> -/* v9fs glib thread pool */
> -static V9fsThPool v9fs_pool;
> +/* Called from QEMU I/O thread. */
> +static void coroutine_enter_cb(void *opaque, int ret)
> +{
> + Coroutine *co = opaque;
> + qemu_coroutine_enter(co, NULL);
> +}
> +
> +/* Called from worker thread. */
> +static int coroutine_enter_func(void *arg)
> +{
> + Coroutine *co = arg;
> + qemu_coroutine_enter(co, NULL);
> + return 0;
> +}
>
> void co_run_in_worker_bh(void *opaque)
> {
> Coroutine *co = opaque;
> - g_thread_pool_push(v9fs_pool.pool, co, NULL);
> -}
> -
> -static void v9fs_qemu_process_req_done(EventNotifier *e)
> -{
> - Coroutine *co;
> -
> - event_notifier_test_and_clear(e);
> -
> - while ((co = g_async_queue_try_pop(v9fs_pool.completed)) != NULL) {
> - qemu_coroutine_enter(co, NULL);
> - }
> -}
> -
> -static void v9fs_thread_routine(gpointer data, gpointer user_data)
> -{
> - Coroutine *co = data;
> -
> - qemu_coroutine_enter(co, NULL);
> -
> - g_async_queue_push(v9fs_pool.completed, co);
> -
> - event_notifier_set(&v9fs_pool.e);
> -}
> -
> -int v9fs_init_worker_threads(void)
> -{
> - int ret = 0;
> - V9fsThPool *p = &v9fs_pool;
> - sigset_t set, oldset;
> -
> - sigfillset(&set);
> - /* Leave signal handling to the iothread. */
> - pthread_sigmask(SIG_SETMASK, &set, &oldset);
> -
> - p->pool = g_thread_pool_new(v9fs_thread_routine, p, -1, FALSE, NULL);
> - if (!p->pool) {
> - ret = -1;
> - goto err_out;
> - }
> - p->completed = g_async_queue_new();
> - if (!p->completed) {
> - /*
> - * We are going to terminate.
> - * So don't worry about cleanup
> - */
> - ret = -1;
> - goto err_out;
> - }
> - event_notifier_init(&p->e, 0);
> -
> - event_notifier_set_handler(&p->e, v9fs_qemu_process_req_done);
> -err_out:
> - pthread_sigmask(SIG_SETMASK, &oldset, NULL);
> - return ret;
> + thread_pool_submit_aio(qemu_get_aio_context()->thread_pool,
> + coroutine_enter_func, co, coroutine_enter_cb, co);
> }
> diff --git a/hw/9pfs/virtio-9p-coth.h b/hw/9pfs/virtio-9p-coth.h
> index 0fbe49a..535743f 100644
> --- a/hw/9pfs/virtio-9p-coth.h
> +++ b/hw/9pfs/virtio-9p-coth.h
> @@ -20,13 +20,6 @@
> #include "virtio-9p.h"
> #include <glib.h>
>
glib.h is no more needed.
> -typedef struct V9fsThPool {
> - EventNotifier e;
> -
> - GThreadPool *pool;
> - GAsyncQueue *completed;
> -} V9fsThPool;
> -
> /*
> * we want to use bottom half because we want to make sure the below
> * sequence of events.
> @@ -45,7 +38,7 @@ typedef struct V9fsThPool {
> qemu_bh_schedule(co_bh); \
> /* \
> * yield in qemu thread and re-enter back \
> - * in glib worker thread \
> + * in worker thread \
> */ \
> qemu_coroutine_yield(); \
> qemu_bh_delete(co_bh); \
> diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c
> index e3abcfa..944b5f5 100644
> --- a/hw/9pfs/virtio-9p-device.c
> +++ b/hw/9pfs/virtio-9p-device.c
> @@ -116,10 +116,6 @@ static void virtio_9p_device_realize(DeviceState *dev,
> Error **errp)
> " and export path:%s", s->fsconf.fsdev_id,
> s->ctx.fs_root);
> goto out;
> }
> - if (v9fs_init_worker_threads() < 0) {
> - error_setg(errp, "worker thread initialization failed");
> - goto out;
> - }
>
> /*
> * Check details of export path, We need to use fs driver