Re: [Qemu-devel] Re: [PATCH] Fix alarm_timer race with select - v3

[Anthony Liguori <anthony@codemonkey.ws>]

Jan Kiszka wrote:
> Changing the default IO timeout to 5 s (#5578) made a race visible
> between the alarm_timer and select() in main_loop_wait(): If the timer
> fired before select was able to block, the full select() timeout could
> have been applied instead of returning immediately. Since #5578, this
> causes heavy problems to the Musicpal board emulation with stalls up to
> 5 s, but also with some older Linux guest kernels.
>
> The following patch introduces a pipe that is written to by
> host_alarm_handler and select()'ed in main_loop_wait(). This avoids
> prevents that select() blocks though a timer has fired and waits for
> processing.
>
> Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
>   

Applied.  Thanks.

Regards,

Anthony Liguori