I'm still scratching my head what the heck this could be.
Increasing the TTM prefault number has minimal more CPU overhead on the
first access but makes subsequent accesses to the same buffer faster
(because the buffer is already completely present).
So as long as Chrome didn't wrote some single bytes repeatably on newly
allocated buffers I don't see how the change could affect video playback
at all.
Maybe Chrome did exactly that because of a bug or something, but in
general such an application behavior wouldn't make much sense (except if
you want to burn CPU cycles).
Anyway not going to look further into that issue.
Thanks,
Christian.
Am 02.08.24 um 11:40 schrieb 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
