When external event sources are disabled fdmon-io_uring falls back to
fdmon-poll. The ->need_wait() callback needs to watch for this so it
can return true when external event sources are disabled.
It is also necessary to call ->wait() when AioHandlers have changed
because io_uring is asynchronous and we must submit new sqes.
Both of these changes to ->need_wait() together fix tests/test-aio -p
/aio/external-client, which failed with:
test-aio: tests/test-aio.c:404: test_aio_external_client: Assertion `aio_poll(ctx, false)' failed.
Reported-by: Julia Suvorova <jusual@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
util/fdmon-io_uring.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/util/fdmon-io_uring.c b/util/fdmon-io_uring.c
index 893b79b622..7e143ef515 100644
--- a/util/fdmon-io_uring.c
+++ b/util/fdmon-io_uring.c
@@ -290,7 +290,18 @@ static int fdmon_io_uring_wait(AioContext *ctx, AioHandlerList *ready_list,
static bool fdmon_io_uring_need_wait(AioContext *ctx)
{
- return io_uring_cq_ready(&ctx->fdmon_io_uring);
+ /* Have io_uring events completed? */
+ if (io_uring_cq_ready(&ctx->fdmon_io_uring)) {
+ return true;
+ }
+
+ /* Do we need to submit new io_uring sqes? */
+ if (!QSLIST_EMPTY_RCU(&ctx->submit_list)) {
+ return true;
+ }
+
+ /* Are we falling back to fdmon-poll? */
+ return atomic_read(&ctx->external_disable_cnt);
}
static const FDMonOps fdmon_io_uring_ops = {
--
2.24.1
On Thu, Mar 19, 2020 at 04:35:59PM +0000, Stefan Hajnoczi wrote: > When external event sources are disabled fdmon-io_uring falls back to > fdmon-poll. The ->need_wait() callback needs to watch for this so it > can return true when external event sources are disabled. > > It is also necessary to call ->wait() when AioHandlers have changed > because io_uring is asynchronous and we must submit new sqes. > > Both of these changes to ->need_wait() together fix tests/test-aio -p > /aio/external-client, which failed with: > > test-aio: tests/test-aio.c:404: test_aio_external_client: Assertion `aio_poll(ctx, false)' failed. > > Reported-by: Julia Suvorova <jusual@redhat.com> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > --- > util/fdmon-io_uring.c | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) Thanks, applied to my block tree: https://github.com/stefanha/qemu/commits/block Stefan
On Thu, Mar 19, 2020 at 04:35:59PM +0000, Stefan Hajnoczi wrote: > When external event sources are disabled fdmon-io_uring falls back to > fdmon-poll. The ->need_wait() callback needs to watch for this so it > can return true when external event sources are disabled. > > It is also necessary to call ->wait() when AioHandlers have changed > because io_uring is asynchronous and we must submit new sqes. > > Both of these changes to ->need_wait() together fix tests/test-aio -p > /aio/external-client, which failed with: > > test-aio: tests/test-aio.c:404: test_aio_external_client: Assertion `aio_poll(ctx, false)' failed. > > Reported-by: Julia Suvorova <jusual@redhat.com> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > --- > util/fdmon-io_uring.c | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) > > diff --git a/util/fdmon-io_uring.c b/util/fdmon-io_uring.c > index 893b79b622..7e143ef515 100644 > --- a/util/fdmon-io_uring.c > +++ b/util/fdmon-io_uring.c > @@ -290,7 +290,18 @@ static int fdmon_io_uring_wait(AioContext *ctx, AioHandlerList *ready_list, > > static bool fdmon_io_uring_need_wait(AioContext *ctx) > { > - return io_uring_cq_ready(&ctx->fdmon_io_uring); > + /* Have io_uring events completed? */ > + if (io_uring_cq_ready(&ctx->fdmon_io_uring)) { > + return true; > + } > + > + /* Do we need to submit new io_uring sqes? */ > + if (!QSLIST_EMPTY_RCU(&ctx->submit_list)) { > + return true; > + } > + > + /* Are we falling back to fdmon-poll? */ > + return atomic_read(&ctx->external_disable_cnt); > } > > static const FDMonOps fdmon_io_uring_ops = { > -- > 2.24.1 > Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
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