[Intel-gfx] [PATCH i-g-t] overlay/intel-gpu-overlay

[Chris Wilson]

On Wed, Nov 18, 2015 at 01:51:57PM +0000, Vlad, Marius C wrote:
> 
> 
> -----Original Message-----
> From: Chris Wilson [mailto:chris at chris-wilson.co.uk] 
> Sent: Wednesday, November 18, 2015 2:59 PM
> To: Vlad, Marius C <marius.c.vlad at intel.com>
> Cc: intel-gfx at lists.freedesktop.org
> Subject: Re: [Intel-gfx] [PATCH i-g-t] overlay/intel-gpu-overlay
> 
> On Wed, Nov 18, 2015 at 02:40:29PM +0200, marius.c.vlad at intel.com wrote:
> > From: Marius Vlad <marius.c.vlad at intel.com>
> > 
> > Use sigaction() instead of signal() and add SIGINT, SIGTERM to close 
> > the overlay window. With this change the overlay window will be 
> > destroyed.
> > 
> > Signed-off-by: Marius Vlad <marius.c.vlad at intel.com>
> > ---
> >  overlay/overlay.c | 42 ++++++++++++++++++++++++++++++++++++------
> >  1 file changed, 36 insertions(+), 6 deletions(-)
> > 
> > diff --git a/overlay/overlay.c b/overlay/overlay.c index 
> > 3c0dbb4..48ba67c 100644
> > --- a/overlay/overlay.c
> > +++ b/overlay/overlay.c
> > @@ -804,11 +804,19 @@ static void show_gem_objects(struct 
> > overlay_context *ctx, struct overlay_gem_obj
> >  
> >  static int take_snapshot;
> >  
> > -static void signal_snapshot(int sig)
> > +static void
> > +signal_snapshot(int sig, siginfo_t *si, void *__unused)
> >  {
> >  	take_snapshot = sig;
> >  }
> >  
> > +static void
> > +signal_x11_destroy(int sig, siginfo_t *si, void *__unused) {
> > +	x11_overlay_stop();
> 
> is not signalsafe.
> 
> Indeed. Any ideas then? I'm hitting a weird system hang if the overlay window is open
> for a period of time (although period ranges to minutes it seems to happen each time). If the window
> is closed and process exits I don't see this behavior. This is entirely different bug but meanwhile 
> wanted to keep my machine running.

Yes, it is a known hw (on ivb/hsw) issue with concurrent access to
registers. We need the i915 perf interface to avoid it (as then we can
serialise all register access).
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre