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

[John Brooks]

On Fri, May 19, 2017 at 05:24:36PM +0200, Marek Olšák wrote:
> Where is your "attached" patch?
> 
> Marek

It's actually a reply to my message. Sorry if that was unclear.

> 
> 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)
> >
> > _______________________________________________
> > amd-gfx mailing list
> > amd-gfx at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/amd-gfx

--
John Brooks