[igt-dev] [Intel-gfx] [PATCH i-g-t v2] runner: Don't kill a test on taint if watching timeouts

[Petri Latvala]

On Thu, Jan 07, 2021 at 09:49:23AM +0000, Chris Wilson wrote:
> Quoting Petri Latvala (2021-01-07 09:40:02)
> > On Wed, Jan 06, 2021 at 09:41:37AM +0000, Chris Wilson wrote:
> > > Quoting Janusz Krzysztofik (2020-12-04 19:50:07)
> > > > We may still be interested in results of a test even if it has tainted
> > > > the kernel.  On the other hand, we need to kill the test on taint if no
> > > > other means of killing it on a jam is active.
> > > > 
> > > > If abort on both kernel taint or a timeout is requested, decrease all
> > > > potential timeouts significantly while the taint is detected instead of
> > > > aborting immediately.  However, report the taint as the reason of the
> > > > abort if a timeout decreased by the taint expires.
> > > 
> > > This has the nasty side effect of not stopping the test run after a
> > > kernel taint. Instead the next test inherits the tainted condition from
> > > the previous test and usually ends up being declared incomplete.
> > > 
> > > False positives are frustrating.
> > > -Chris
> > 
> > 
> > Do you have a link to a test run where this happened? This patch
> > didn't change the between-tests abort checks.
> 
> The taint is from the warnings in the penultimate test:
> https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_9550/shard-skl7/igt_runner20.txt

Ah, I see.

https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_9550/shard-skl7/dmesg20.txt

This is the tainting WARN I presume:

<4>[  917.575173] Memory manager not clean during takedown.
<4>[  917.575272] WARNING: CPU: 2 PID: 7 at drivers/gpu/drm/drm_mm.c:999 drm_mm_takedown+0x51/0x100

That happens after @gem, before @evict.

In other words, this is all in the same exec() of i915_selftest
--run-subtest live. Incorrect _dynamic_ subtest gets blamed.

Getting the killing right here is a bit tricky, possibly doable. Or
rather, getting the blame right is doable, killing will be inherently
racy...


-- 
Petri Latvala