[igt-dev] [PATCH i-g-t 1/2] tests/gem_exec_await: Relax the busy spinner

[Chris Wilson]

Quoting Tvrtko Ursulin (2018-11-19 15:33:56)
> 
> On 19/11/2018 15:28, Chris Wilson wrote:
> > Quoting Tvrtko Ursulin (2018-11-19 15:22:28)
> >> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> >>
> >> Add some nop instructions between recursive batch buffer start calls to
> >> give system some breathing room. Without these, especially when coupled
> >> with memory pressure, false GPU hangs can be observed caused by the
> >> inability of the chip to cope.
> > 
> > Doesn't seem to be required. And the machines most susceptible to timer
> > errors due to busyspin have not show the issue.
> 
> With the memory pressure subtest, the second patch in this series, it 
> was make it or break it to have the nops. Without them it was GPU hangs 
> all around, and with them so far all clean.

First machine bsw, just applying patch 2/2,

IGT-Version: 1.23-gb6b8d829 (x86_64) (Linux: 4.20.0-rc2+ x86_64)
Using Execlists submission
Ring size: 131 batches
Starting subtest: wide-all
wide: 420 cycles: 24121.034us
Subtest wide-all: SUCCESS (47.060s)
Starting subtest: wide-contexts
wide: 340 cycles: 24893.896us
Subtest wide-contexts: SUCCESS (22.265s)
Starting subtest: wide-contexts-mempressure
wide: 232 cycles: 25153.899us
Subtest wide-contexts-mempressure: SUCCESS (23.141s)

:|
-Chris