[Intel-gfx] [PATCH 0/3] Per Engine hang detection and recovery

[Daniel Vetter]

On Mon, Nov 11, 2013 at 02:58:31PM +0000, Siluvery, Arun wrote:
> From: "Siluvery, Arun" <arun.siluvery at intel.com>
> 
> This patchset contains changes for Timeout detection and recovery (TDR) which
> provides per-engine hang detection and recovery.
> The current driver performs full gpu reset in case of a hang, TDR attempts to
> only reset the engine that is hung and it falls back to full reset if it fails.
> 
> Full GPU reset can leave the system in a state where the display updates
> intermittently and possibly lock-up depending on the work load at the time of
> hang. TDR can help recover the system in those case thus increasing the stability.

Are these hw lockups you've seen with full gpu reset or just kernel
deadlocks? If it's the latter we've recently (re-)fixed a bunch of those,
and if there are new ones we definitely want to fix them and add testcases
to igt. So if you could share some of these hangs and their
analysis/testcases that's be very interesting.

That's of course on top of any other reset improvements.

> The changes are split in multiple patches.
> 1. Ring utility functions to save/restore context, reset ring etc
> 2. TDR hang detection logic and error recovery function
> 3. Debugfs changes to export TDR statistics.
> 
> I have tested these changes on drm-intel-nightly with simple test which
> inserts a bad batch buffer on the specific to trigger a hang. TDR logic
> then detects this and recovers from it by skipping the bad batch.

I want this testcase (as a patch to igt).

> Please review and give your comments.

I'll try to have a look later this week, atm still busy with bdw
upstreaming. One more meta-comment though: Something with your git setup
seems to be broken, the patches don't have in-reply-to headers pointing at
this cover letter and hence the threading is a bit broken.

Cheers, Daniel
> 
> regards
> Arun
> 
> Siluvery, Arun (3):
>   drm/1915: Add ring functions to save/restore context for per-ring
>     reset
>   drm/i915: Per-engine Timeout detection and recovery on HSW
>   drm/i915: Export TDR hang count to debugfs
> 
>  drivers/gpu/drm/i915/i915_debugfs.c     |  68 +++-
>  drivers/gpu/drm/i915/i915_dma.c         |  16 +-
>  drivers/gpu/drm/i915/i915_drv.c         | 195 +++++++++-
>  drivers/gpu/drm/i915/i915_drv.h         |  92 ++++-
>  drivers/gpu/drm/i915/i915_gem.c         |  77 +++-
>  drivers/gpu/drm/i915/i915_gpu_error.c   |  25 +-
>  drivers/gpu/drm/i915/i915_irq.c         | 556 ++++++++++++++++-------------
>  drivers/gpu/drm/i915/i915_reg.h         |   7 +
>  drivers/gpu/drm/i915/intel_display.c    |  25 +-
>  drivers/gpu/drm/i915/intel_ringbuffer.c | 607 +++++++++++++++++++++++++++++++-
>  drivers/gpu/drm/i915/intel_ringbuffer.h |  51 +++
>  drivers/gpu/drm/i915/intel_uncore.c     |  31 +-
>  include/drm/drmP.h                      |   7 +
>  13 files changed, 1467 insertions(+), 290 deletions(-)
> 
> -- 
> 1.8.4
> 
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch