Bug 96907 - piglit.spec.arb_gpu_shader5.arb_gpu_shader5-emitstreamvertex_nodraw intermittent
Summary: piglit.spec.arb_gpu_shader5.arb_gpu_shader5-emitstreamvertex_nodraw intermittent
Status: NEW
Alias: None
Product: Mesa
Classification: Unclassified
Component: Drivers/DRI/i965 (show other bugs)
Version: git
Hardware: Other All
: medium normal
Assignee: Kenneth Graunke
QA Contact: Intel 3D Bugs Mailing List
Keywords: bisected
: 91301 (view as bug list)
Depends on:
Reported: 2016-07-12 19:59 UTC by Mark Janes
Modified: 2017-02-05 08:01 UTC (History)
1 user (show)

See Also:
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Description Mark Janes 2016-07-12 19:59:47 UTC
This test fails intermittently with the following signature:

/tmp/build_root/m64/lib/piglit/bin/arb_gpu_shader5-emitstreamvertex_nodraw -auto -fbo
piglit: debug: Requested an OpenGL 3.2 Core Context, and received a matching 3.3 context

Probe color at (50,50)
  Expected: 0.000000 0.000000 0.000000
  Observed: 1.000000 0.000000 0.000000

Bisected to:
commit df31c1850d14729e27513ae733110a668f6b6e95
Author: Kenneth Graunke <kenneth@whitecape.org>
i965/gs: Use new NIR intrinsics.

By performing the vertex counting in NIR, we're able to elide a
ton of useless safety checks around every EmitVertex() call:

total instructions in shared programs: 3952 -> 3720 (-5.87%)
instructions in affected programs:     3491 -> 3259 (-6.65%)
helped:                                11
HURT:                                  0

Improves performance in Gl32GSCloth by 0.671742% +/-
0.142202% (n=621) on Haswell GT3e at 1024x768.

This should also make it easier to implement Broadwell's "Static
Vertex Count" feature someday.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>
Comment 1 Mark Janes 2016-07-12 20:08:12 UTC
Ken, please verify my bisection before spending too much time on this.  It was difficult and time consuming to reproduce.  I was able to trigger the test failure by running the test in a loop, while simultaneously running a full piglit suite in another window.  Here are the ways I invoked the two workloads:

for ((;;)) do /tmp/build_root/m64/lib/piglit/bin/arb_gpu_shader5-emitstreamvertex_nodraw -auto -fbo; done


piglit run -o -p gbm --exclude-tests timestamp-get --exclude-tests glsl-routing --exclude-tests ext_timer_query --exclude-tests arb_timer_query --exclude-tests spec.khr_debug.object-label_gl --exclude-tests arb_framebuffer_no_attachments.arb_framebuffer_no_attachments-atomic --exclude-tests vs-float-main-return --config /home/jenkins/workspace/Leeroy/piglit-test//ivb.conf --exclude-tests glsl-1.10.execution.vs-vec2-main-return --exclude-tests spec.egl.1.4.eglquerysurface.egl --exclude-tests spec.egl.ext.client.extensions.conformance --exclude-tests spec.egl.khr.create.context --exclude-tests spec.egl.khr.get.all.proc.addresses --exclude-tests spec.egl.khr.surfaceless.context --exclude-tests spec.egl.mesa.configless.context --exclude-tests spec.egl.nok.swap.region --exclude-tests spec.egl.nok.texture.from.pixmap.basic --exclude-tests spec.egl.1.4.eglterminate.then.unbind.context --exclude-tests spec.egl.chromium.sync.control.conformance --exclude-tests arb.shader.image.load.store.execution.coherency-extra --exclude-tests arb.separate.shader.objects.validateprogrampipeline --exclude-tests glsl-1.50.execution.geometry.clip-distance --exclude-tests glsl-1.50.execution.gs-redeclares-pervertex-out-only --exclude-tests glsl-1.50.execution.redeclare-pervertex-subset-vs-to-gs --exclude-tests glsl-1.50.transform-feedback-type-and-size --exclude-tests arb.sync.clientwaitsync-timeout --exclude-tests arb.compute.shader.zero-dispatch-size -c gpu /tmp/build_root/m64/test/ivbgt2

In my tests, the looping test generally failed while the first few hundred tests in the piglit suite were executing.  Occasionally, I would have to restart the piglit suite to produce the failure.  Also, the looping test failed around test 4000 more than once.

I spent several iterations confirming that the looping test failed at the bisected revision, and I could never make it fail on the previous revision.

This failure mode has been seen on IVBGT2 and BXT.
Comment 2 Mark Janes 2016-07-12 20:12:53 UTC
*** Bug 91301 has been marked as a duplicate of this bug. ***
Comment 3 Kenneth Graunke 2016-07-13 05:25:17 UTC
I think your bisect is correct.
Comment 4 Mark Janes 2017-01-30 23:47:50 UTC
This is confirmed to be a regression for Mesa 17.
Comment 5 Mark Janes 2017-02-05 08:01:24 UTC
This bug shipped with mesa 11.1, so it is not a regression for later releases.

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