Re: [Qemu-devel] [PATCH v2] block: avoid SIGUSR2

[Paolo Bonzini]

On 10/28/2011 01:33 PM, Kevin Wolf wrote:
> I'm afraid that we can only avoid things like this reliably if we
> convert all devices to be direct users of AIO/coroutines. The current
> block layer infrastructure doesn't emulate the behaviour of bdrv_read
> accurately as bottom halves can be run in the nested main loop.
>
> For floppy, the following seems to be a quick fix (Lucas, Cleber, does
> this solve your problems?), though it's not very satisfying. And I'm not
> quite sure yet why it doesn't always happen with kill() in
> posix-aio-compat.c.

Another "fix" is to change idle bottom halves (at least the one in 
hw/dma.c) to 10ms timers.

Paolo