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[Qemu-devel] [PATCH v1 11/17] linux-aio: handling -EAGAIN for !s->io_q.p
From: |
Ming Lei |
Subject: |
[Qemu-devel] [PATCH v1 11/17] linux-aio: handling -EAGAIN for !s->io_q.plugged case |
Date: |
Tue, 5 Aug 2014 11:33:12 +0800 |
Previously -EAGAIN is simply ignored for !s->io_q.plugged case,
and sometimes it is easy to cause -EIO to VM, such as NVME device.
This patch handles -EAGAIN by io queue for !s->io_q.plugged case,
and it will be retried in following aio completion cb.
Suggested-by: Paolo Bonzini <address@hidden>
Signed-off-by: Ming Lei <address@hidden>
---
block/linux-aio.c | 22 +++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/block/linux-aio.c b/block/linux-aio.c
index 4cdf507..0e21f76 100644
--- a/block/linux-aio.c
+++ b/block/linux-aio.c
@@ -238,6 +238,11 @@ static int ioq_enqueue(struct qemu_laio_state *s, struct
iocb *iocb)
s->io_q.iocbs[idx++] = iocb;
s->io_q.idx = idx;
+ /* don't submit until next completion for -EAGAIN of non plug case */
+ if (unlikely(!s->io_q.plugged)) {
+ return 0;
+ }
+
/* submit immediately if queue depth is above 2/3 */
if (idx > s->io_q.size * 2 / 3) {
return ioq_submit(s, true);
@@ -305,10 +310,25 @@ BlockDriverAIOCB *laio_submit(BlockDriverState *bs, void
*aio_ctx, int fd,
io_set_eventfd(&laiocb->iocb, event_notifier_get_fd(&s->e));
if (!s->io_q.plugged) {
- if (io_submit(s->ctx, 1, &iocbs) < 0) {
+ int ret;
+
+ if (!s->io_q.idx) {
+ ret = io_submit(s->ctx, 1, &iocbs);
+ } else {
+ ret = -EAGAIN;
+ }
+ /*
+ * Switch to queue mode until -EAGAIN is handled, we suppose
+ * there is always uncompleted I/O, so try to enqueue it first,
+ * and will be submitted again in following aio completion cb.
+ */
+ if (ret == -EAGAIN) {
+ goto enqueue;
+ } else if (ret < 0) {
goto out_free_aiocb;
}
} else {
+ enqueue:
if (ioq_enqueue(s, iocbs) < 0) {
goto out_free_aiocb;
}
--
1.7.9.5
- Re: [Qemu-devel] [PATCH v1 02/17] dataplane: use object pool to speed up allocation for virtio blk request, (continued)
- [Qemu-devel] [PATCH v1 03/17] qemu coroutine: support bypass mode, Ming Lei, 2014/08/04
- [Qemu-devel] [PATCH v1 04/17] block: prepare for supporting selective bypass coroutine, Ming Lei, 2014/08/04
- [Qemu-devel] [PATCH v1 05/17] garbage collector: introduced for support of bypass coroutine, Ming Lei, 2014/08/04
- [Qemu-devel] [PATCH v1 06/17] block: introduce bdrv_co_can_bypass_co, Ming Lei, 2014/08/04
- [Qemu-devel] [PATCH v1 07/17] block: support to bypass qemu coroutinue, Ming Lei, 2014/08/04
- [Qemu-devel] [PATCH v1 08/17] Revert "raw-posix: drop raw_get_aio_fd() since it is no longer used", Ming Lei, 2014/08/04
- [Qemu-devel] [PATCH v1 09/17] dataplane: enable selective bypassing coroutine, Ming Lei, 2014/08/04
- [Qemu-devel] [PATCH v1 10/17] linux-aio: fix submit aio as a batch, Ming Lei, 2014/08/04
- [Qemu-devel] [PATCH v1 11/17] linux-aio: handling -EAGAIN for !s->io_q.plugged case,
Ming Lei <=
- [Qemu-devel] [PATCH v1 12/17] linux-aio: increase max event to 256, Ming Lei, 2014/08/04
- [Qemu-devel] [PATCH v1 13/17] linux-aio: remove 'node' from 'struct qemu_laiocb', Ming Lei, 2014/08/04
- [Qemu-devel] [PATCH v1 14/17] hw/virtio/virtio-blk.h: introduce VIRTIO_BLK_F_MQ, Ming Lei, 2014/08/04
- [Qemu-devel] [PATCH v1 15/17] virtio-blk: support multi queue for non-dataplane, Ming Lei, 2014/08/04
- [Qemu-devel] [PATCH v1 16/17] virtio-blk: dataplane: support multi virtqueue, Ming Lei, 2014/08/04
- [Qemu-devel] [PATCH v1 17/17] hw/virtio-pci: introduce num_queues property, Ming Lei, 2014/08/04
- Re: [Qemu-devel] [PATCH v1 00/17] dataplane: optimization and multi virtqueue support, Stefan Hajnoczi, 2014/08/05