Re: [PATCH v1 0/2] Add timeout mechanism to qmp actions

[Kevin Wolf]

Am 10.08.2020 um 16:52 hat Zhenyu Ye geschrieben:
> Before doing qmp actions, we need to lock the qemu_global_mutex,
> so the qmp actions should not take too long time.
> 
> Unfortunately, some qmp actions need to acquire aio context and
> this may take a long time.  The vm will soft lockup if this time
> is too long.

Do you have a specific situation in mind where getting the lock of an
AioContext can take a long time? I know that the main thread can
block for considerable time, but QMP commands run in the main thread, so
this patch doesn't change anything for this case. It would be effective
if an iothread blocks, but shouldn't everything running in an iothread
be asynchronous and therefore keep the AioContext lock only for a short
time?

Kevin