[Bug 89438] New: [BDW/BSW bisected] SynMark2_v6_0_0_OglDrvCtx performance reduce by 12% with gnome-session

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=89438

            Bug ID: 89438
           Summary: [BDW/BSW bisected] SynMark2_v6_0_0_OglDrvCtx
                    performance reduce by 12% with gnome-session
           Product: Mesa
           Version: 10.5
          Hardware: All
                OS: Linux (All)
            Status: NEW
          Severity: normal
          Priority: medium
         Component: Drivers/DRI/i965
          Assignee: idr at freedesktop.org
          Reporter: yex.tian at intel.com
        QA Contact: intel-3d-bugs at lists.freedesktop.org
                CC: krh at bitplanet.net

Created attachment 114017
  --> https://bugs.freedesktop.org/attachment.cgi?id=114017&action=edit
Xorg info

System Environment: 
Regression: Yes     
Platform:  BDW BSW
Kernel:  V3.19
Libdrm:(master)libdrm-2.4.59-31-gf799a527db2851b2890146a9ce777f73fea30176
Mesa:  (10.5)c32d83528189be988275c9ccbd3bbb2e48ee4362
Xserver: (server-1.16-branch)xorg-server-1.16.4
Xf86_video_intel:(master)2.99.917-165-gf6ba71ac194a19c80aa64f4769f76a47ebb7bd16
Cairo:  (master)70cc8f250b5669e757b4f044571ba0f71e3dea9e
Libva:  (master)f9741725839ea144e9a6a1827f74503ee39946c3
Libva_intel_driver: (master)e8fde1cdaafb93c2b54d6092a728d099ad7cdd11

Bug detailed description:
--------------------------------------------------
SynMark2_v6_0_0_OglDrvCtx performance reduce by 12% with gnome-session on BDW
and BSW. The problem also exists on latest Master branch.
It's Mesa regression. By bisected, show that ee5fb8d1 is the first bad commit.
Its parents commit (7ff457b9) is good.

commit ee5fb8d1ba7f50ed94e1a34fa0f6e15a0588145e  
Author:     Kristian Høgsberg <krh at bitplanet.net>
AuthorDate: Mon Oct 20 23:29:41 2014 -0700
Commit:     Kristian Høgsberg <krh at bitplanet.net>
CommitDate: Wed Dec 10 12:29:27 2014 -0800

    i965: Generate vs code using scalar backend for BDW+

    With everything in place, we can now use the scalar backend compiler for
    vertex shaders on BDW+.  We make scalar vertex shaders the default on
    BDW+ but add a new vec4vs debug option to force the vec4 backend.

    No piglit regressions.

    Performance impact is minimal, I see a ~1.5 improvement on the T-Rex
    GLBenchmark case, but in general it's in the noise.  Some of our
    internal synthetic, vs bounded benchmarks show great improvement, 20%-40%
    in some cases, but real-world cases are mostly unaffected.

    Signed-off-by: Kristian Høgsberg <krh at bitplanet.net>
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org> 

Please see Xrog.0.log.

Reproduce steps:
----------------------------
1, xinit& 
2, gnome-session&
3, ./synmark2 OglDrvCtx

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/intel-3d-bugs/attachments/20150305/8119b534/attachment.html>