| Message ID | 20240506190622.56095-2-stefanha@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Revert "monitor: use aio_co_reschedule_self()" | expand |
CC-ing stable since 1f25c172f83704e350c0829438d832384084a74d is in 9.0.0 Am 06.05.24 um 21:06 schrieb Stefan Hajnoczi: > Commit 1f25c172f837 ("monitor: use aio_co_reschedule_self()") was a code > cleanup that uses aio_co_reschedule_self() instead of open coding > coroutine rescheduling. > > Bug RHEL-34618 was reported and Kevin Wolf <kwolf@redhat.com> identified > the root cause. I missed that aio_co_reschedule_self() -> > qemu_get_current_aio_context() only knows about > qemu_aio_context/IOThread AioContexts and not about iohandler_ctx. It > does not function correctly when going back from the iohandler_ctx to > qemu_aio_context. > > Go back to open coding the AioContext transitions to avoid this bug. > > This reverts commit 1f25c172f83704e350c0829438d832384084a74d. > > Buglink: https://issues.redhat.com/browse/RHEL-34618 > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > --- > qapi/qmp-dispatch.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/qapi/qmp-dispatch.c b/qapi/qmp-dispatch.c > index f3488afeef..176b549473 100644 > --- a/qapi/qmp-dispatch.c > +++ b/qapi/qmp-dispatch.c > @@ -212,7 +212,8 @@ QDict *coroutine_mixed_fn qmp_dispatch(const QmpCommandList *cmds, QObject *requ > * executing the command handler so that it can make progress if it > * involves an AIO_WAIT_WHILE(). > */ > - aio_co_reschedule_self(qemu_get_aio_context()); > + aio_co_schedule(qemu_get_aio_context(), qemu_coroutine_self()); > + qemu_coroutine_yield(); > } > > monitor_set_cur(qemu_coroutine_self(), cur_mon); > @@ -226,7 +227,9 @@ QDict *coroutine_mixed_fn qmp_dispatch(const QmpCommandList *cmds, QObject *requ > * Move back to iohandler_ctx so that nested event loops for > * qemu_aio_context don't start new monitor commands. > */ > - aio_co_reschedule_self(iohandler_get_aio_context()); > + aio_co_schedule(iohandler_get_aio_context(), > + qemu_coroutine_self()); > + qemu_coroutine_yield(); > } > } else { > /*
Am 29.05.2024 um 12:33 hat Fiona Ebner geschrieben:
> CC-ing stable since 1f25c172f83704e350c0829438d832384084a74d is in 9.0.0
Good point, I'm also updating the commit message in my tree to add
a Cc: line. Thanks for catching this, Fiona!
Kevin
diff --git a/qapi/qmp-dispatch.c b/qapi/qmp-dispatch.c index f3488afeef..176b549473 100644 --- a/qapi/qmp-dispatch.c +++ b/qapi/qmp-dispatch.c @@ -212,7 +212,8 @@ QDict *coroutine_mixed_fn qmp_dispatch(const QmpCommandList *cmds, QObject *requ * executing the command handler so that it can make progress if it * involves an AIO_WAIT_WHILE(). */ - aio_co_reschedule_self(qemu_get_aio_context()); + aio_co_schedule(qemu_get_aio_context(), qemu_coroutine_self()); + qemu_coroutine_yield(); } monitor_set_cur(qemu_coroutine_self(), cur_mon); @@ -226,7 +227,9 @@ QDict *coroutine_mixed_fn qmp_dispatch(const QmpCommandList *cmds, QObject *requ * Move back to iohandler_ctx so that nested event loops for * qemu_aio_context don't start new monitor commands. */ - aio_co_reschedule_self(iohandler_get_aio_context()); + aio_co_schedule(iohandler_get_aio_context(), + qemu_coroutine_self()); + qemu_coroutine_yield(); } } else { /*
Commit 1f25c172f837 ("monitor: use aio_co_reschedule_self()") was a code cleanup that uses aio_co_reschedule_self() instead of open coding coroutine rescheduling. Bug RHEL-34618 was reported and Kevin Wolf <kwolf@redhat.com> identified the root cause. I missed that aio_co_reschedule_self() -> qemu_get_current_aio_context() only knows about qemu_aio_context/IOThread AioContexts and not about iohandler_ctx. It does not function correctly when going back from the iohandler_ctx to qemu_aio_context. Go back to open coding the AioContext transitions to avoid this bug. This reverts commit 1f25c172f83704e350c0829438d832384084a74d. Buglink: https://issues.redhat.com/browse/RHEL-34618 Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> --- qapi/qmp-dispatch.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)