[Bug 34493] New: r600g performance regression introduced by 467023e8 (Marek Olšák: r600g: use the same upload buffer for vertices, indices, and constants)

[Bug 34493] New: r600g performance regression introduced by 467023e8 (Marek Olšák: r600g: use the same upload buffer for vertices, indices, and constants)

[bugzilla-daemon]

https://bugs.freedesktop.org/show_bug.cgi?id=34493

           Summary: r600g performance regression introduced by 467023e8
                    (Marek Olšák: r600g: use the same upload buffer for
                    vertices, indices, and constants)
           Product: Mesa
           Version: git
          Platform: x86-64 (AMD64)
        OS/Version: Linux (All)
            Status: NEW
          Severity: normal
          Priority: medium
         Component: Drivers/Gallium/r600
        AssignedTo: dri-devel@lists.freedesktop.org
        ReportedBy: dawitbro@sbcglobal.net


As detailed in Comment 6 of bug 34156, I found this regression in Mesa 7.11-git
while trying to pin down another performance regression a few commits earlier.

I was able to create a local branch where I was able to reverts 4 commits from
a series by Henri Verbeet, which restored performance to the level which
existed before that series was introduced.  Performance remained high after the
4 reverts until commit 467023e8 was introduced.

Reverting this commit (in addition to the 4 mentioned in the other bug report:
077c448d, 7687eaba, 1fa95c7f, and a77e813d) restores performance.  All further
Mesa commits through the next 10 days (up to the HEAD I have currently, which
is fd8d4b32 of Feb. 18) are working fine.

I am using r600g on 64-bit Linux, with the following hardware + software:

Hardware:  Radeon HD 5750 (Evergreen JUNIPER)

Software:
  kernel 2.6.37 (+ radeon cherry-picks from drm-fixes)
  libdrm 2.4.23
  xorg-server 1.9.4
  xf86-video-ati 6.14.0


If I can provide any further info/assistance, just let me know.

-- 
Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel

[Bug 34493] r600g performance regression introduced by 467023e8 (Marek Olšák: r600g: use the same upload buffer for vertices, indices, and constants)

[bugzilla-daemon]

https://bugs.freedesktop.org/show_bug.cgi?id=34493

--- Comment #1 from Marek Olšák <maraeo@gmail.com> 2011-03-01 14:09:55 PST ---
It's unclear to me how using one buffer instead of three can decrease
performance.

-- 
Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel

[Bug 34493] r600g performance regression introduced by 467023e8 (Marek Olšák: r600g: use the same upload buffer for vertices, indices, and constants)

[bugzilla-daemon]

https://bugs.freedesktop.org/show_bug.cgi?id=34493

--- Comment #2 from Dave Witbrodt <dawitbro@sbcglobal.net> 2011-03-01 15:12:14 PST ---
(In reply to comment #1)
> It's unclear to me how using one buffer instead of three can decrease
> performance.

I am not a developer, so I cannot comment on the code.  Indeed, regarding the
other bug report I mentioned (#34156) I was asked by Henri (private msg) to do
some profiling tests:  I know what that means, but I do not (yet) have any
experience with it, and have not found time to experiment with it in the past 2
weeks.  I just barely know enough 'git' usage to create a local branch with the
(five) problem commits reverted.

I wonder if anyone else can confirm the regression(s) I am reporting.  I'm
using Mesa r600g on Radeon HD 5750.  Running performance tests at 3b1c1f02 (the
commit before performance dropped for me) followed by 467023e8 (the subject of
the current bug report) should reveal a big difference.

If not, then it's just me... and the bug could be rejected as invalid.  It
could be hardware-specific, it could be PEBKAC (if I did something wrong
creating the local branch with the 5 commits removed), etc.

I was planning on testing the Mesa HEAD this weekend, including updating my
local branch to see if any new commits are affecting performance.  Maybe these
code changes are features, not bugs -- providing other benefits more important
than the performance effects.  I was just so happy to see the major increase in
performance in January that I hate the idea of losing it in the more recent
work!

-- 
Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug 34493] r600g performance regression introduced by 467023e8 (Marek Olšák: r600g: use the same upload buffer for vertices, indices, and constants)

[bugzilla-daemon]

https://bugs.freedesktop.org/show_bug.cgi?id=34493

--- Comment #3 from Marek Olšák <maraeo@gmail.com> 2011-03-01 15:45:37 PST ---
There will be more performance improvements soon. I know how to improve it by
50% or more, it's just not very high on my priority list currently.

-- 
Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel

[Bug 34493] r600g performance regression introduced by 467023e8 (Marek Olšák: r600g: use the same upload buffer for vertices, indices, and constants)

[bugzilla-daemon]

https://bugs.freedesktop.org/show_bug.cgi?id=34493

--- Comment #4 from Dave Witbrodt <dawitbro@sbcglobal.net> 2011-03-01 17:01:14 PST ---
(In reply to comment #3)
> There will be more performance improvements soon. I know how to improve it by
> 50% or more, it's just not very high on my priority list currently.

Oh!  Well, thank you for that (in advance)!

My purpose in testing for regressions was to find a way to contribute back to
the community.  Since I am not (yet) able to write code, or properly debug
code, I thought I could at least report changes in performance and/or behavior
in the build systems.  I'm getting the vibe that reporting performance
regressions is not deemed a meaningful way to contribute.  Is that correct?

-- 
Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug 34493] r600g performance regression introduced by 467023e8 (Marek Olšák: r600g: use the same upload buffer for vertices, indices, and constants)

[bugzilla-daemon]

https://bugs.freedesktop.org/show_bug.cgi?id=34493

--- Comment #5 from Marek Olšák <maraeo@gmail.com> 2011-03-01 17:19:14 PST ---
(In reply to comment #4)
> (In reply to comment #3)
> > There will be more performance improvements soon. I know how to improve it by
> > 50% or more, it's just not very high on my priority list currently.
> 
> Oh!  Well, thank you for that (in advance)!
> 
> My purpose in testing for regressions was to find a way to contribute back to
> the community.  Since I am not (yet) able to write code, or properly debug
> code, I thought I could at least report changes in performance and/or behavior
> in the build systems.  I'm getting the vibe that reporting performance
> regressions is not deemed a meaningful way to contribute.  Is that correct?

It's very useful to report performance regressions. Just in this case, it's not
obvious to me what's wrong with the commit. There are not many developers, so
it might be hard to get attention quickly especially if it's not a
show-stopper, but developers usually read bug reports and, thanks to that, are
aware of existing issues.

-- 
Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel

[Bug 34493] r600g performance regression introduced by 467023e8 (Marek Olšák: r600g: use the same upload buffer for vertices, indices, and constants)

[bugzilla-daemon]

https://bugs.freedesktop.org/show_bug.cgi?id=34493

--- Comment #6 from Dave Witbrodt <dawitbro@sbcglobal.net> 2011-03-01 20:01:16 PST ---
(In reply to comment #5)
> It's very useful to report performance regressions. Just in this case, it's not
> obvious to me what's wrong with the commit. There are not many developers, so
> it might be hard to get attention quickly especially if it's not a
> show-stopper, but developers usually read bug reports and, thanks to that, are
> aware of existing issues.

OK, thanks for the clarification.

I will continue my local testing of Mesa master and my own branch with any
problem commits I find reverted -- as long as I am able, I mean.

In the coming weeks I should finally be finding time to begin learning the
code.  Maybe this sort of testing -- profiling, identifying code changes that
affect performance, and explaining the reason for those effects -- will be my
way of learning the code base.

FTR, by pointing out performance problems I find, I am not seeking immediate
fixes or attention for those particular problems.  I am merely hoping to
provide info to developers, in case the info is important.  Mesa actually works
fine for me from master... just 1/3 slower.  ;)

-- 
Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug 34493] r600g performance regression introduced by 467023e8 (Marek Olšák: r600g: use the same upload buffer for vertices, indices, and constants)

[bugzilla-daemon]

https://bugs.freedesktop.org/show_bug.cgi?id=34493

--- Comment #7 from Dave Witbrodt <dawitbro@sbcglobal.net> 2011-04-11 20:15:46 PDT ---
I have been away from Linux and testing radeon support since the Japan crisis
began.  Updating to Mesa 7.11.0-devel, commit a26121f3, caused the same
slowdown I had observed before:  min/max framerate in 'torcs' dropped from
28/54 fps to 17/34 fps.  I was planning on restoring local packages of my last
fast-working Mesa, but decided to rebuild my entire X stack against my newly
updated kernel (updated from 2.6.38-rc8 to 2.6.38.2).

To my shock, I found that replacing xorg-server 1.9.99.903 with 1.10.0.902 and
updating the radeon driver to the latest git version, 6.14.99-devel, commit
cc7d1fa3 -- both built against the Mesa mentioned above -- improved Mesa
performance in 'torcs' dramatically.  It is no longer as consistently high as I
was getting, but gives me 17/54 fps.

I also notice that another test program, 'prboom-plus', has dramatically
improved performance all around.  As a result, I am abandoning my local git
branch where I intended to pin down the exact cause of the performance changes
-- I haven't touch it for 7 weeks anyway -- and start following the Mesa HEAD
again.

Sorry for the false alarm.  It appears that Mesa changes alone were not to
blame for whatever performance problems I was experiencing.

-- 
Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug 34493] r600g performance regression introduced by 467023e8 (Marek Olšák: r600g: use the same upload buffer for vertices, indices, and constants)

[bugzilla-daemon]

https://bugs.freedesktop.org/show_bug.cgi?id=34493

Jerome Glisse <glisse@freedesktop.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED

--- Comment #8 from Jerome Glisse <glisse@freedesktop.org> 2012-02-22 10:08:11 PST ---
Closing reopen if it's still an issue with newer r600g

-- 
Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.