[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH 07/26] block: add the support to drain throttled req
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH 07/26] block: add the support to drain throttled requests |
Date: |
Thu, 12 Apr 2012 14:00:57 +0200 |
From: Zhi Yong Wu <address@hidden>
Signed-off-by: Zhi Yong Wu <address@hidden>
[ Iterate until all block devices have processed all requests,
add comments. - Paolo ]
Signed-off-by: Paolo Bonzini <address@hidden>
---
block.c | 21 ++++++++++++++++++++-
1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/block.c b/block.c
index 4b96654..33efa95 100644
--- a/block.c
+++ b/block.c
@@ -863,12 +863,31 @@ void bdrv_close_all(void)
*
* This function does not flush data to disk, use bdrv_flush_all() for that
* after calling this function.
+ *
+ * Note that completion of an asynchronous I/O operation can trigger any
+ * number of other I/O operations on other devices---for example a coroutine
+ * can be arbitrarily complex and a constant flow of I/O can come until the
+ * coroutine is complete. Because of this, it is not possible to have a
+ * function to drain a single device's I/O queue.
*/
void bdrv_drain_all(void)
{
BlockDriverState *bs;
+ bool busy;
- qemu_aio_flush();
+ do {
+ busy = qemu_aio_wait();
+
+ /* FIXME: We do not have timer support here, so this is effectively
+ * a busy wait.
+ */
+ QTAILQ_FOREACH(bs, &bdrv_states, list) {
+ if (!qemu_co_queue_empty(&bs->throttled_reqs)) {
+ qemu_co_queue_restart_all(&bs->throttled_reqs);
+ busy = true;
+ }
+ }
+ } while (busy);
/* If requests are still pending there is a bug somewhere */
QTAILQ_FOREACH(bs, &bdrv_states, list) {
--
1.7.9.3
- [Qemu-devel] [PATCH 00/26] My block patches queue for 1.1, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 01/26] qemu-io: use main_loop_wait, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 02/26] qemu-tool: map vm_clock to rt_clock, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 03/26] posix-aio: merge posix_aio_process_queue and posix_aio_read, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 05/26] aio: return "AIO in progress" state from qemu_aio_wait, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 04/26] aio: remove process_queue callback and qemu_aio_process_queue, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 07/26] block: add the support to drain throttled requests,
Paolo Bonzini <=
- Re: [Qemu-devel] [PATCH 07/26] block: add the support to drain throttled requests, Zhi Yong Wu, 2012/04/12
- Re: [Qemu-devel] [PATCH 07/26] block: add the support to drain throttled requests, Paolo Bonzini, 2012/04/13
- Re: [Qemu-devel] [PATCH 07/26] block: add the support to drain throttled requests, Zhi Yong Wu, 2012/04/13
- Re: [Qemu-devel] [PATCH 07/26] block: add the support to drain throttled requests, Paolo Bonzini, 2012/04/13
- Re: [Qemu-devel] [PATCH 07/26] block: add the support to drain throttled requests, Zhi Yong Wu, 2012/04/13
- Re: [Qemu-devel] [PATCH 07/26] block: add the support to drain throttled requests, Paolo Bonzini, 2012/04/13
- Re: [Qemu-devel] [PATCH 07/26] block: add the support to drain throttled requests, Zhi Yong Wu, 2012/04/13
- Re: [Qemu-devel] [PATCH 07/26] block: add the support to drain throttled requests, Zhi Yong Wu, 2012/04/13
[Qemu-devel] [PATCH 08/26] block: add mode argument to blockdev-snapshot-sync, Paolo Bonzini, 2012/04/12
[Qemu-devel] [PATCH 06/26] aio: simplify qemu_aio_wait, Paolo Bonzini, 2012/04/12