From: Daniel Vetter <daniel@ffwll.ch>
To: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>,
Ben Widawsky <ben@bwidawsk.net>,
intel-gfx <intel-gfx@lists.freedesktop.org>
Subject: Re: [PATCH] drm/i915: kicking rings considered harmful
Date: Tue, 27 Sep 2011 20:03:17 +0200 [thread overview]
Message-ID: <20110927180317.GC2785@phenom.ffwll.local> (raw)
In-Reply-To: <c55c5d$k5v25@AZSMGA002.ch.intel.com>
On Tue, Sep 27, 2011 at 06:31:59PM +0100, Chris Wilson wrote:
> On Tue, 27 Sep 2011 09:46:14 -0700, Ben Widawsky <ben@bwidawsk.net> wrote:
> > On Tue, 27 Sep 2011 12:03:22 +0200
> > Daniel Vetter <daniel@ffwll.ch> wrote:
> >
> > > On Mon, Sep 26, 2011 at 10:22:01PM -0700, Ben Widawsky wrote:
> > > > On Mon, 26 Sep 2011 19:59:50 +0200
> > > > Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
> > > > > diff --git a/drivers/gpu/drm/i915/i915_irq.c
> > > > > b/drivers/gpu/drm/i915/i915_irq.c index da5d607..09c11e4 100644
> > > > > --- a/drivers/gpu/drm/i915/i915_irq.c
> > > > > +++ b/drivers/gpu/drm/i915/i915_irq.c
> > > > > @@ -1694,7 +1694,7 @@ void i915_hangcheck_elapsed(unsigned long data)
> > > > > if (dev_priv->hangcheck_count++ > 1) {
> > > > > DRM_ERROR("Hangcheck timer elapsed... GPU
> > > > > hung\n");
> > > > > - if (!IS_GEN2(dev)) {
> > > > > + if (!IS_GEN2(dev) && i915_try_reset) {
> > > > > /* Is the chip hanging on a
> > > > > WAIT_FOR_EVENT?
> > > > > * If so we can simply poke the
> > > > > RB_WAIT bit
> > > > > * and break the hang. This should
> > > > > work on
> > > >
> > > > I think you should also be able to accomplish the same thing
> > > > with enable_hangcheck param. I had the same problem with the
> > > > debugger :)
> > >
> > > I agree. Iirc you have some patches floating in that area to make the
> > > hangcheck a bit more robust. Can you maybe add this to that series and
> > > (re-)submit?
> > >
> > > Cheers, Daniel
> >
> > While 9/10 times daniel > ben, I'm playing my 10% card here and
> > suggesting that mixing the reset variable and ring kick is not the right
> > way to go about this.
>
> One purpose of the i915.reset parameter is to disable any automatic
> attempts to recover from a hang condition so that the error state is not
> misleading. So preventing the kick ring does help in that regard.
>
> A second purpose is to prevent i915_reset() from causing havoc and hanging
> the machine. Daniel is implying that kicking the rings is instrumental in
> making matters worse. Again using i915.reset to prevent kicking the rings
> fits in with that purpose.
>
> Since I regard kicking rings as a form of reset, I don't see it as a
> conflation of terms and so a valid use of i915.reset.
Couldn't have said it any better. The bad effects of kicking stuck rings
is mostly that when we have a sync problem there's a decent chance
somebody has written garbage into our batchbuffers. Continously trying to
execute said garbage is just tempting faith in the gpu's error resilience.
-Daniel
--
Daniel Vetter
Mail: daniel@ffwll.ch
Mobile: +41 (0)79 365 57 48
next prev parent reply other threads:[~2011-09-27 18:02 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-13 5:38 [2.6.39 regression] hard lock when GNOME starts Andrew Lutomirski
2011-05-13 16:07 ` Andrew Lutomirski
2011-05-13 16:14 ` [PATCH] drm/i915: Revert i915.semaphore=1 default from 47ae63e0 Andy Lutomirski
2011-05-15 23:09 ` Keith Packard
2011-05-19 19:56 ` Keith Packard
2011-05-19 20:50 ` Andrew Lutomirski
2011-05-24 17:10 ` Andrew Lutomirski
2011-05-24 17:46 ` Keith Packard
2011-05-24 20:05 ` Ivan Bulatovic
2011-06-07 7:12 ` Eric Anholt
2011-06-10 14:06 ` Andrew Lutomirski
2011-08-22 16:53 ` Jesse Barnes
2011-08-31 18:24 ` Ben Widawsky
2011-08-31 18:30 ` Andrew Lutomirski
2011-08-31 19:07 ` Keith Packard
2011-08-31 19:37 ` Andrew Lutomirski
2011-09-26 17:59 ` [PATCH] drm/i915: kicking rings considered harmful Daniel Vetter
2011-09-26 19:07 ` Andrew Lutomirski
2011-09-27 9:57 ` Daniel Vetter
2011-09-27 5:22 ` Ben Widawsky
2011-09-27 10:03 ` Daniel Vetter
2011-09-27 16:46 ` Ben Widawsky
2011-09-27 17:31 ` Chris Wilson
2011-09-27 18:03 ` Daniel Vetter [this message]
2011-09-27 19:38 ` Ben Widawsky
2011-09-27 21:54 ` Chris Wilson
2011-09-28 1:34 ` Ben Widawsky
2011-09-28 8:47 ` Chris Wilson
2011-09-28 8:53 ` Daniel Vetter
2011-10-03 20:21 ` Andrew Lutomirski
2011-10-03 21:02 ` Daniel Vetter
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