Re: [Qemu-devel] Qemu: Guest Linux hangs on Mac OS X 10.11

[Peter Maydell]

On 9 November 2015 at 11:46, Peter Maydell <address@hidden> wrote:
> Yep, just confirmed that current master with commit b553a0428
> reverted displays the bug again.

After a bunch of "try building specific object files with optimization
off to see where the problem goes away" tests, I've narrowed the
problem down further: if you tell clang to disable optimization by
adding __attribute__ ((optnone)) to the two functions
hpet_time_after() and hpet_time_after64() in hw/timer/hpet.c then
the problem goes away.

My current theory is that we're doing something here that's not
valid C and the compiler ends up optimizing it into something
that results in the timer setting the next-timeout to a very
short interval and that's what's hogging the main-loop time.
I'll look in more detail after lunch.

thanks
-- PMM