AMD-GFX Archive mirror
 help / color / mirror / Atom feed
From: Tvrtko Ursulin <tursulin@igalia.com>
To: amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org
Cc: kernel-dev@igalia.com,
	"Tvrtko Ursulin" <tvrtko.ursulin@igalia.com>,
	"Christian König" <christian.koenig@amd.com>,
	"Friedrich Vock" <friedrich.vock@gmx.de>
Subject: [RFC v2 0/2] Discussion around eviction improvements
Date: Thu, 16 May 2024 13:18:20 +0100	[thread overview]
Message-ID: <20240516121822.19036-1-tursulin@igalia.com> (raw)

From: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>

Reduced re-spin of my previous series after Christian corrected a few
misconceptions that I had. So lets see if what remains makes sense or is still
misguided.

To summarise, the series address the following two issues:

 * Migration rate limiting does not work, at least not for the common case
   where userspace configures VRAM+GTT. It thinks it can stop migration attempts
   by playing with bo->allowed_domains vs bo->preferred domains but, both from
   the code, and from empirical experiments, I see that not working at all. When
   both masks are identical fiddling with them achieves nothing. Even when they
   are not identical allowed has a fallback GTT placement which means that when
   over the migration budget ttm_bo_validate with bo->allowed_domains can cause
   migration from GTT to VRAM.

 * Driver thinks it will be re-validating evicted buffers on the next submission
   but it does not for the very common case of VRAM+GTT because it only checks
   if current placement is *none* of the preferred placements.

These two patches appear to have a positive result for a memory intensive game
like Assassin's Creed Valhalla. On an APU like Steam Deck the game has a working
set around 5 GiB, while the VRAM is configured to 1 GiB. Correctly respecting
the migration budget appears to keep buffer blits at bay and improves the
minimum frame rate, ie. makes things smoother.

From the game's built-in benchmark, average of three runs each:

						FPS
		migrated KiB	min	avg	max	min-1%	min-0.1%
  because	   20784781	10.00  37.00   89.67    22.00    12.33
  patched	    4227688	13.67  37.00   81.33    23.33    15.00

Disclaimers that I have is that more runs would be needed to be more confident
about the results. And more games. And APU versus discrete.

Cc: Christian König <christian.koenig@amd.com>
Cc: Friedrich Vock <friedrich.vock@gmx.de>

Tvrtko Ursulin (2):
  drm/amdgpu: Re-validate evicted buffers
  drm/amdgpu: Actually respect buffer migration budget

 drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 112 +++++++++++++++++++------
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c |  21 ++++-
 2 files changed, 103 insertions(+), 30 deletions(-)

-- 
2.44.0


             reply	other threads:[~2024-05-16 12:18 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-05-16 12:18 Tvrtko Ursulin [this message]
2024-05-16 12:18 ` [RFC 1/2] drm/amdgpu: Re-validate evicted buffers Tvrtko Ursulin
2024-05-16 12:18 ` [RFC 2/2] drm/amdgpu: Actually respect buffer migration budget Tvrtko Ursulin
2024-05-16 19:21 ` [RFC v2 0/2] Discussion around eviction improvements Alex Deucher
2024-05-17  7:41   ` Tvrtko Ursulin
2024-05-17 13:43     ` Alex Deucher
2024-05-31  9:12   ` Christian König
2024-05-30 10:17 ` Tvrtko Ursulin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20240516121822.19036-1-tursulin@igalia.com \
    --to=tursulin@igalia.com \
    --cc=amd-gfx@lists.freedesktop.org \
    --cc=christian.koenig@amd.com \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=friedrich.vock@gmx.de \
    --cc=kernel-dev@igalia.com \
    --cc=tvrtko.ursulin@igalia.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).