bisected/regression: choopy youtube video on Ryzen IGP - 0ddd2ae586d2 drm/ttm: increase ttm pre-fault value to PMD size

[Yanko Kaneti]

Hi, 

So, can't reproduce this any more with with recent rawhide (rc1+).
Tried also with the same old kernels but this time its with newer mesa
and google-chrome (126 -> 127). The same scenario as before now works
ok.

Cheers and sorry for the noise.
- Yanko

On Wed, 2024-07-24 at 10:13 +0300, Yanko Kaneti wrote:
> Hi,
> 
> Well, it starts, then within a second or two it begins stuttering with
> long (half a second/second) freezes of the video , while the audio seems
> to work fine. Nothing in the log from chrome or kernel , AFAICS,  to
> show anything is wrong.
> 
> Regards
> Yanko
> 
> On Wed, 2024-07-24 at 09:02 +0200, Christian König wrote:
> > Hi Yanko,
> > 
> > interesting. What do you mean with "choppy"? E.g. lag on startup?
> > 
> > Regards,
> > Christian.
> > 
> > Am 23.07.24 um 21:42 schrieb Yanko Kaneti:
> > > Hello,
> > > 
> > > Noticed and bisected a rawhide (with the new 6.11-rc0 snapshots) regression to this commit:
> > > 
> > >    0ddd2ae586d2 drm/ttm: increase ttm pre-fault value to PMD size
> > > 
> > > The regression manifests in choppy youtube video playback in google-chrome-stable.
> > >   https://www.youtube.com/watch?v=uOpl2XNOgMA
> > >   google-chrome-stable-126.0.6478.182-1.x86_64
> > >   VP9 video,
> > >   Chrome -> Override software rendering list -> on
> > >   Chrome -> Hardware-accelerated video decode - default enabled
> > > 
> > > No other visible graphics issues.
> > > 
> > > Its a desktop system with Ryzen 7 5700GRyzen 7 5700G  IGP
> > > [AMD/ATI] Cezanne [Radeon Vega Series / Radeon Vega Mobile Series] [1002:1638]
> > > 
> > > Tested with linus tip and just reverting the commit fixes the issue.
> > > 
> > > Sorry for the brevity, not sure what other details might be relevant.
> > > 
> > > - Yanko
> > > 
> > > 
> > 
>