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Re: [Qemu-devel] [PATCH v4 06/10] coroutine: add co_aio_sleep_ns() to al
From: |
Stefan Hajnoczi |
Subject: |
Re: [Qemu-devel] [PATCH v4 06/10] coroutine: add co_aio_sleep_ns() to allow sleep in block drivers |
Date: |
Tue, 30 Jul 2013 15:58:58 +0200 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Fri, Jul 26, 2013 at 03:10:48PM +0900, MORITA Kazutaka wrote:
> This helper function behaves similarly to co_sleep_ns(), but the
> sleeping coroutine will be resumed when using qemu_aio_wait().
>
> Signed-off-by: MORITA Kazutaka <address@hidden>
> ---
> include/block/coroutine.h | 8 ++++++++
> qemu-coroutine-sleep.c | 47
> +++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 55 insertions(+)
>
> diff --git a/include/block/coroutine.h b/include/block/coroutine.h
> index 377805a..23ea6e9 100644
> --- a/include/block/coroutine.h
> +++ b/include/block/coroutine.h
> @@ -210,6 +210,14 @@ void qemu_co_rwlock_unlock(CoRwlock *lock);
> void coroutine_fn co_sleep_ns(QEMUClock *clock, int64_t ns);
>
> /**
> + * Yield the coroutine for a given duration
> + *
> + * Behaves similarly to co_sleep_ns(), but the sleeping coroutine will be
> + * resumed when using qemu_aio_wait().
> + */
> +void coroutine_fn co_aio_sleep_ns(int64_t ns);
> +
> +/**
> * Yield until a file descriptor becomes readable
> *
> * Note that this function clobbers the handlers for the file descriptor.
> diff --git a/qemu-coroutine-sleep.c b/qemu-coroutine-sleep.c
> index 169ce5c..3955347 100644
> --- a/qemu-coroutine-sleep.c
> +++ b/qemu-coroutine-sleep.c
> @@ -13,6 +13,7 @@
>
> #include "block/coroutine.h"
> #include "qemu/timer.h"
> +#include "qemu/thread.h"
>
> typedef struct CoSleepCB {
> QEMUTimer *ts;
> @@ -37,3 +38,49 @@ void coroutine_fn co_sleep_ns(QEMUClock *clock, int64_t ns)
> qemu_del_timer(sleep_cb.ts);
> qemu_free_timer(sleep_cb.ts);
> }
> +
> +typedef struct CoAioSleepCB {
> + QEMUBH *bh;
> + int64_t ns;
> + Coroutine *co;
> +} CoAioSleepCB;
> +
> +static void co_aio_sleep_cb(void *opaque)
> +{
> + CoAioSleepCB *aio_sleep_cb = opaque;
> +
> + qemu_coroutine_enter(aio_sleep_cb->co, NULL);
> +}
> +
> +static void *sleep_thread(void *opaque)
> +{
> + CoAioSleepCB *aio_sleep_cb = opaque;
> + struct timespec req = {
> + .tv_sec = aio_sleep_cb->ns / 1000000000,
> + .tv_nsec = aio_sleep_cb->ns % 1000000000,
> + };
> + struct timespec rem;
> +
> + while (nanosleep(&req, &rem) < 0 && errno == EINTR) {
This breaks the Windows build and makes qemu_aio_wait() spin instead of
blocking (wastes CPU).
I think Alex Bligh and Ping Fan's QEMUTimer in AioContext work is needed
here. I have CCed them. Their patches would allow you to use
co_sleep_ns() in qemu_aio_wait().
> + req = rem;
> + }
> +
> + qemu_bh_schedule(aio_sleep_cb->bh);
> +
> + return NULL;
> +}
> +
> +void coroutine_fn co_aio_sleep_ns(int64_t ns)
> +{
> + CoAioSleepCB aio_sleep_cb = {
> + .ns = ns,
> + .co = qemu_coroutine_self(),
> + };
> + QemuThread thread;
> +
> + aio_sleep_cb.bh = qemu_bh_new(co_aio_sleep_cb, &aio_sleep_cb);
> + qemu_thread_create(&thread, sleep_thread, &aio_sleep_cb,
> + QEMU_THREAD_DETACHED);
> + qemu_coroutine_yield();
> + qemu_bh_delete(aio_sleep_cb.bh);
> +}
> --
> 1.8.1.3.566.gaa39828
>
>
- [Qemu-devel] [PATCH v4 00/10] sheepdog: reconnect server after connection failure, MORITA Kazutaka, 2013/07/26
- [Qemu-devel] [PATCH v4 06/10] coroutine: add co_aio_sleep_ns() to allow sleep in block drivers, MORITA Kazutaka, 2013/07/26
- Re: [Qemu-devel] [PATCH v4 06/10] coroutine: add co_aio_sleep_ns() to allow sleep in block drivers,
Stefan Hajnoczi <=
- [Qemu-devel] [PATCH v4 02/10] iov: handle EOF in iov_send_recv, MORITA Kazutaka, 2013/07/26
- [Qemu-devel] [PATCH v4 10/10] sheepdog: check simultaneous create in resend_aioreq, MORITA Kazutaka, 2013/07/26
- [Qemu-devel] [PATCH v4 01/10] ignore SIGPIPE in qemu-img and qemu-io, MORITA Kazutaka, 2013/07/26
- [Qemu-devel] [PATCH v4 03/10] sheepdog: check return values of qemu_co_recv/send correctly, MORITA Kazutaka, 2013/07/26
- [Qemu-devel] [PATCH v4 05/10] sheepdog: reload inode outside of resend_aioreq, MORITA Kazutaka, 2013/07/26
- [Qemu-devel] [PATCH v4 09/10] sheepdog: cancel aio requests if possible, MORITA Kazutaka, 2013/07/26
- [Qemu-devel] [PATCH v4 08/10] sheepdog: make add_aio_request and send_aioreq void functions, MORITA Kazutaka, 2013/07/26
- [Qemu-devel] [PATCH v4 07/10] sheepdog: try to reconnect to sheepdog after network error, MORITA Kazutaka, 2013/07/26