Re: libva decoding performance regression with kernel 4.0-rc

From: Olivier Crête
Date: Fri Apr 10 2015 - 19:26:14 EST


Hello,

Thanks for the quick reply!

With my real use-cases:

1. 9x 720p60 mpeg2 videos
- 4.0-rc6: ~12 frames per second are on time
- 4.0-rc6 + reverts: a stable 45 frames per second are on time
- 044307a9: 40-45 frames per second are on time
- 0a24802a: 45-46 frames per second are on time

2. 1080i30 mpeg2 videos
- 4.0-rc6: 5 videos
- 044307a9: 10 videos
- 0a24802a: 10 videos

So you basically beat my baseline too, good job, thanks a lot! Any
chance you can sneak this into 4.0 ?

Olivier

On Fri, 2015-04-10 at 07:23 +0100, Chris Wilson wrote:
> On Thu, Apr 09, 2015 at 09:00:43PM -0400, Olivier CrÃte wrote:
> > Hello,
> >
> > Using an Atom E3845 board, we had a pretty bad performance regression
> > when upgrading to 4.0-rc6 from 3.19. With the help of git bisect, I
> > traced it back to commit 78a42377. Reverting this commit and subsequent
> > related commits (b9ffd80, 71745376, etc) fixes the performance
> > regression for me.
>
> Can you please test
>
> http://cgit.freedesktop.org/~ickle/linux-2.6/log/?h=for-olivier-crete
>
> on your setup.
>
> First
> http://cgit.freedesktop.org/~ickle/linux-2.6/commit/?h=for-olivier-crete&id=044307a99b418258ac0d775460d73b20b80277c1
> to get a baseline with nightly as that contains some fine tuning to the
> batch allocations, which is pretty significant for libva on Atom (only
> double clflushing one or two pages every batch rather than 128) and then
> http://cgit.freedesktop.org/~ickle/linux-2.6/commit/?h=for-olivier-crete&id=0a24802a5b61403b887ce401ce3efd52f5fd1eac
> to see if the command parser tuning helps.
>
> Hope this helps,
> -Chris
>

--
Olivier CrÃte
olivier.crete@xxxxxxxxxxxxx

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