Bug 89402

Summary: [HSW mobile bisected]Unigine-heaven performance reduce by 12% with gnome-session
Product: Mesa Reporter: ye.tian <yex.tian>
Component: Drivers/DRI/i965Assignee: Matt Turner <mattst88>
Status: RESOLVED MOVED QA Contact: Intel 3D Bugs Mailing List <intel-3d-bugs>
Severity: normal    
Priority: high CC: christophe.prigent, eero.t.tamminen, martin.peres
Version: unspecified   
Hardware: All   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments: Xorg.0.log info

Description ye.tian 2015-03-03 07:10:11 UTC 
System Environment:       
Platform:  HSW mobile
Kernel: 3.19.0-rc7+
Libdrm: (master)libdrm-2.4.59-20-g7cb1d6e2d6c63e3bc4b275ff073152b550ba5b0f
Mesa:   (master)599cbe5508ccb246fe06b64116c84ce976165fed
Xserver:(master)xorg-server-1.17.0-16-g3a06faf3fcdb7451125a46181f9152e8e59e9770
Xf86_video_intel:(master)2.99.917-145-g127aae5a72a69df325fed0b63d345e81583d5ca1

Bug detailed description:
--------------------------------------------------
Unigine-heaven performance reduce by 12% with gnome-session on HSW mobile, reduce by 6.5% on HSW desktop.
It’s Mesa regression. By bisected, show that 2dad1e3a is the first bad commit.

commit 2dad1e3abdb1ad153289455f3e273101e5bac1a8
Author:     Matt Turner <mattst88@gmail.com>
AuthorDate: Wed Feb 12 11:00:46 2014 -0800
Commit:     Matt Turner <mattst88@gmail.com>
CommitDate: Tue Feb 17 20:44:09 2015 -0800

    i965/fs: Add pass to combine immediates.

    total instructions in shared programs: 5885407 -> 5940958 (0.94%)
    instructions in affected programs:     3617311 -> 3672862 (1.54%)
    helped:                                3
    HURT:                                  23556
    GAINED:                                31
    LOST:                                  165

    ... but will allow us to always emit MAD instructions.

    Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

Please see Xrog.0.log.

Reproduce steps:
----------------------------
1, xinit& 
2, gnome-session&
3, vblank_mode=0 ./bin/heaven_x64 -video_app opengl -data_path ../ -sound_app null -engine_config ../data/heaven_4.0.cfg -system_script heaven/unigine.cpp -video_mode -1 -video_fullscreen 1 -extern_define PHORONIX,RELEASE -video_width 1920 -video_height 1080
Comment 1 ye.tian 2015-03-03 07:11:17 UTC 
Created attachment 113936 [details]
Xorg.0.log info
Comment 2 Eero Tamminen 2015-03-03 08:03:53 UTC 
> by 12% with gnome-session on HSW mobile

This is GT3e.

> by 6.5% on HSW desktop

This is GT2.
Comment 3 ye.tian 2015-03-03 08:05:17 UTC 
Right.
Comment 4 Eero Tamminen 2015-03-03 09:20:49 UTC 
Same commit also regresses PSPom test a bit and clearly improves GfxBench ALU test, GpuTest volplosion & Piano tests, maybe a bit also PSBump2.

On GT3e we see much larger effect on Heaven (our GT3e is diffferent version).  We're also seeing the effect on all platforms, not just on HSW or GT3e, although on others it's much smaller than with (HSW) GT3e.

Because there's both performance increase & decrease, commit doesn't need to be reverted.
Comment 5 Eero Tamminen 2015-09-10 09:51:26 UTC 
Matt, this regression is still visible in Heaven performance (Martin has graph that show how the Heaven perf drops on BDW and it keeping down ever after).

Do you have some plan on how the get previous performance back, without regressing test-cases which that commit improved?
Comment 6 GitLab Migration User 2019-09-25 18:53:29 UTC 
-- GitLab Migration Automatic Message --

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