On Wed, 2008-07-16 at 15:50 +0100, Mark McLoughlin wrote: > The race was observed with a modified kvm-userspace when > running a guest under heavy network load. When it occurs, > KVM never sees another SIGALRM signal because although > the signal is queued up the appropriate bit is never set > in the pending mask. Manually sending the process a SIGALRM > kicks it out of this state.
I should clarify what I mean by "modified kvm-userspace". Basically, I was trying out a suggestion of Marcelo's to drop the global qemu mutex when reading GSO packets from a tap device i.e. @@ -4299,7 +4299,9 @@ static void tap_send(void *opaque) sbuf.buf = s->buf; s->size = getmsg(s->fd, NULL, &sbuf, &f) >=0 ? sbuf.len : -1; #else + kvm_mutex_unlock(); s->size = read(s->fd, s->buf, sizeof(s->buf)); + kvm_mutex_lock(); It seems to work fine, but more on that later ... important thing is that if people see a hard-to-reproduce condition where things seem to slow down or lock up, try manually doing a "kill -ALRM $(qemu)" and if that fixes it, then you're probably seeing this bug. Cheers, Mark. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html