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<b><a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO - [SKL] GPU hangs in benchmarks using compute shaders with drm-tip v4.20-rc kernels"
href="https://bugs.freedesktop.org/show_bug.cgi?id=108820#c12">Comment # 12</a>
on <a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO - [SKL] GPU hangs in benchmarks using compute shaders with drm-tip v4.20-rc kernels"
href="https://bugs.freedesktop.org/show_bug.cgi?id=108820">bug 108820</a>
from <span class="vcard"><a class="email" href="mailto:jakub@okonski.org" title="Jakub Okoński <jakub@okonski.org>"> <span class="fn">Jakub Okoński</span></a>
</span></b>
<pre>OK, I think I found the precise issue. It occurs when using a control flow
barrier in the shader with more than 64 items in the workgroup.
To put in concrete terms:
Shader A:
...
layout (local_size_x = 64) in;
void main() {
// code
barrier();
}
----
Works fine.
Shader B:
...
layout (local_size_x = 65) in;
void main() {
// code
barrier();
}
----
Hangs with INTEL-MESA: error: src/intel/vulkan/anv_device.c:2091: GPU hung on
one of our command buffers (VK_ERROR_DEVICE_LOST).
Shader C:
...
layout (local_size_x = 65) in;
void main() {
// code
// barrier(); without any control flow barriers inside
}
----
Works fine as well.
This should be enough to zoom into the issue, but if you need code you can
execute and repro locally, let me know and I can deliver it.</pre>
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