Bug 109505 - [GEN9+] 2% perf drop in Unigine Heaven, 1% in Valley
Summary: [GEN9+] 2% perf drop in Unigine Heaven, 1% in Valley
Status: NEW
Alias: None
Product: Mesa
Classification: Unclassified
Component: Drivers/DRI/i965 (show other bugs)
Version: git
Hardware: x86-64 (AMD64) All
: medium normal
Assignee: Intel 3D Bugs Mailing List
QA Contact: Intel 3D Bugs Mailing List
Depends on:
Blocks: mesa-19.0
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Reported: 2019-01-30 16:11 UTC by Eero Tamminen
Modified: 2019-02-11 16:58 UTC (History)
0 users

See Also:
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Description Eero Tamminen 2019-01-30 16:11:33 UTC
* Ubuntu 18.04
* Unity / compiz desktop
* X server git version with modifiers enabled
* drm-tip kernel v4.19 or v4.20
* Mesa git version

Between following Mesa commits:
* 2018-12-13 17:49:48 9ebc00f32e: i965: Enable nir_opt_idiv_const for 32 and 64-bit integers
* 2018-12-14 17:40:27 5c454661c6: i965/gen9: Add workarounds for object preemption

Unigine Heaven 4.0 and Valley 1.0 performance regressed.

On SKL GT4e, perf drop is:
- 2% in Heaven (high quality, tessellation enabled, no MSAA, fullscreen)
- 1% in Valley

On slower machines, drop is somewhat smaller.  Drop is GEN9+ specific, or at least it's not visible on older platforms.  There may be some minuscule regression also in heavier GfxBench tests, but it's too smaller to say for sure.
Comment 1 Eero Tamminen 2019-02-11 16:58:24 UTC
Something on the kernel side in drm-tip git improved Heaven performance by similar amount it dropped with Mesa in December.  That didn't affect Valley though.

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