On Wed, 14 Dec 2011, Avi Kivity wrote:

On 12/14/2011 02:16 PM, Marcelo Tosatti wrote:

quoted

quoted

Having this controlled from userspace means it doesn't work for SIGSTOP
or for long scheduling delays.  What about doing this automatically
based on preempt notifiers?

Long scheduling delays should be considered hangups from the guest
perspective.

Why?  To the guest it looks like slow hardware, but it will interpret it
as a softlockup.

quoted

About SIGSTOP, that is a corner case. Unsure if its even properly supported 
by QEMU.

It works from my experience.

-- 
error compiling committee.c: too many arguments to function

And if the soft lockup warning is a concern here, we can have a SIGCONT handler
set the flag the same way qemu stop/cont does.