Apologies for resurrecting an old thread, but I'm experiencing the same issue. For me it manifests mostly as choppy scrolling in Mullvad Browser (Flatpak), also Firefox. E.g. on https://github.com/dandavison/delta, when trackpad flick-scrolling down the page, it's quite smooth up until the sections headed "Line numbers" and "Merge conflicts", there the scrolling hangs for maybe half a sec, then continues onwards. I've yet to debug further why these sections in particular trip up scrolling. But it happens on other websites too (not all, i.e. simple pages are fine). I independently bisected it down to the same commit as Yanko; commit 0ddd2ae586d28e521d37393364d989ce118802e0: drm/ttm: increase ttm pre-fault value to PMD size. Reverting this commit on top of mainline master (d74da846046a) fixes the problem and scrolling is then smooth again. I'm also using a Ryzen IGP; Radeon 780M (1002:15bf) as part of 7840U. I'm running Arch Linux with all packages up to date, nothing else really abstract about my setup. Please let me know if I can help to investigate further. On 02/08/2024 10:46, Christian König wrote: > 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 >>>>> >>>>> >
