[PATCH 0/3] drm/amdgpu: Tweaks for high pressure on CPU visible VRAM

[Marek Olšák]

Where is your "attached" patch?

Marek

On Fri, May 19, 2017 at 5:04 AM, John Brooks <john at fastquake.com> wrote:
> I'm glad this is being worked on. However, somewhat to my surprise, this patch
> series didn't help Dying Light's BO eviction problem. For those who don't know,
> that game performs very badly in certain areas, and it is correlated with
> increased TTM eviction rates. Relevant screenshots of gallium HUD and sysprof:
>
> http://www.fastquake.com/images/screen-dlgalliumhud1-20170513-171241.png
> http://www.fastquake.com/images/screen-dlsysprof-20170515-225919.png
>
> I noticed last week that adding RADEON_DOMAIN_GTT to the domains in radeonsi
> (patch: http://www.fastquake.com/files/text/radeon-gtt.txt ) greatly improved
> performance in these areas, to the tune of about a 30fps increase. Obviously,
> putting GTT in every buffer's domain is not a proper solution. But it lead me
> to believe that perhaps the problem wasn't just the swapping of resident BOs,
> but the creation of new ones that only have VRAM in their domain, and they
> cause existing BOs to be evicted from visible VRAM unconditionally.
>
> The attached patch assigns GTT as the busy placement for newly created BOs that
> have the AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED flag, so that they will go to
> GTT if visible VRAM is full, instead of evicting established BOs. Since there
> is no way to know what the usage patterns of a new BO will be, we shouldn't
> evict established BOs (for which we have hypothetically had the opportunity to
> gather usage data) from visible VRAM for new, unknown BOs.
>
> With this patch I get hugely improved performance in Dying Light just like with
> the Mesa patch: I observed 30-40fps where I got 14 before, and 60fps where I
> got 40 before. TTM evictions and bytes moved have dropped to zero where they
> were exceedingly high before. Buffer evictions no longer dominate the prof
> trace. Screenshots:
>
> http://www.fastquake.com/images/screen-dl-gtt_busy_only-20170518-192602.png
> http://www.fastquake.com/images/screen-dlsysprof-gttpatch-20170518-223200.png
>
> --
> John Brooks (Frogging101)
>
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