From: Daniel Vetter <daniel@ffwll.ch>
To: "Christian König" <ckoenig.leichtzumerken@gmail.com>
Cc: "ML Mesa-dev" <mesa-dev@lists.freedesktop.org>,
dri-devel <dri-devel@lists.freedesktop.org>,
"Marek Olšák" <maraeo@gmail.com>
Subject: Re: [Mesa-dev] [RFC] Linux Graphics Next: Explicit fences everywhere and no BO fences - initial proposal
Date: Wed, 28 Apr 2021 11:54:08 +0200 [thread overview]
Message-ID: <YIkwwD1z7r4BbEZU@phenom.ffwll.local> (raw)
In-Reply-To: <153487a3-082b-faf7-2a4d-ae15993b2a5d@gmail.com>
On Wed, Apr 28, 2021 at 08:59:47AM +0200, Christian König wrote:
> Hi Dave,
>
> Am 27.04.21 um 21:23 schrieb Marek Olšák:
> > Supporting interop with any device is always possible. It depends on
> > which drivers we need to interoperate with and update them. We've
> > already found the path forward for amdgpu. We just need to find out how
> > many other drivers need to be updated and evaluate the cost/benefit
> > aspect.
> >
> > Marek
> >
> > On Tue, Apr 27, 2021 at 2:38 PM Dave Airlie <airlied@gmail.com
> > <mailto:airlied@gmail.com>> wrote:
> >
> > On Tue, 27 Apr 2021 at 22:06, Christian König
> > <ckoenig.leichtzumerken@gmail.com
> > <mailto:ckoenig.leichtzumerken@gmail.com>> wrote:
> > >
> > > Correct, we wouldn't have synchronization between device with
> > and without user queues any more.
> > >
> > > That could only be a problem for A+I Laptops.
> >
> > Since I think you mentioned you'd only be enabling this on newer
> > chipsets, won't it be a problem for A+A where one A is a generation
> > behind the other?
> >
>
> Crap, that is a good point as well.
>
> >
> > I'm not really liking where this is going btw, seems like a ill
> > thought out concept, if AMD is really going down the road of designing
> > hw that is currently Linux incompatible, you are going to have to
> > accept a big part of the burden in bringing this support in to more
> > than just amd drivers for upcoming generations of gpu.
> >
>
> Well we don't really like that either, but we have no other option as far as
> I can see.
>
> I have a couple of ideas how to handle this in the kernel without
> dma_fences, but it always require more or less changes to all existing
> drivers.
Yeah one horrible idea is to essentially do the plan we hashed out for
adding userspace fences to drm_syncobj timelines. And then add drm_syncobj
as another implicit fencing thing to dma-buf.
But:
- This is horrible. We're all agreeing that implicit sync is not a great
idea, building an entire new world on this flawed thing doesn't sound
like a good path forward.
- It's kernel uapi, so it's going to be forever.
- It's only fixing the correctness issue, since you have to stall for
future/indefinite fences at the beginning of the CS ioctl. Or at the
beginning of the atomic modeset ioctl, which kinda defeats the point of
nonblocking.
- You still have to touch all kmd drivers.
- For performance, you still have to glue a submit thread onto all gl
drivers.
It is horrendous.
-Daniel
>
> Christian.
>
> >
> > Dave.
> >
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2021-04-28 9:54 UTC|newest]
Thread overview: 105+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-19 10:47 [RFC] Linux Graphics Next: Explicit fences everywhere and no BO fences - initial proposal Marek Olšák
2021-04-19 15:48 ` Jason Ekstrand
2021-04-20 2:25 ` Marek Olšák
2021-04-20 10:15 ` [Mesa-dev] " Christian König
2021-04-20 10:34 ` Daniel Vetter
2021-04-20 11:03 ` Marek Olšák
2021-04-20 11:16 ` Daniel Vetter
2021-04-20 11:59 ` Christian König
2021-04-20 14:09 ` Daniel Vetter
2021-04-20 16:24 ` Jason Ekstrand
2021-04-20 16:19 ` Jason Ekstrand
2021-04-20 12:01 ` Daniel Vetter
2021-04-20 12:19 ` [Mesa-dev] " Christian König
2021-04-20 13:03 ` Daniel Stone
2021-04-20 14:04 ` Daniel Vetter
2021-04-20 12:42 ` Daniel Stone
2021-04-20 15:45 ` Jason Ekstrand
2021-04-20 17:44 ` Daniel Stone
2021-04-20 18:00 ` [Mesa-dev] " Christian König
2021-04-20 18:15 ` Daniel Stone
2021-04-20 19:03 ` Bas Nieuwenhuizen
2021-04-20 19:18 ` Daniel Stone
2021-04-20 18:53 ` Daniel Vetter
2021-04-20 19:14 ` Daniel Stone
2021-04-20 19:29 ` Daniel Vetter
2021-04-20 20:32 ` Daniel Stone
2021-04-26 20:59 ` Marek Olšák
2021-04-27 8:02 ` Daniel Vetter
2021-04-27 11:49 ` Marek Olšák
2021-04-27 12:06 ` Christian König
2021-04-27 12:11 ` Marek Olšák
2021-04-27 12:15 ` Daniel Vetter
2021-04-27 12:27 ` Christian König
2021-04-27 12:46 ` Marek Olšák
2021-04-27 12:50 ` Christian König
2021-04-27 13:26 ` Marek Olšák
2021-04-27 15:13 ` Christian König
2021-04-27 17:31 ` Lucas Stach
2021-04-27 17:35 ` Simon Ser
2021-04-27 18:01 ` Alex Deucher
2021-04-27 18:27 ` Simon Ser
2021-04-28 10:01 ` Daniel Vetter
2021-04-28 10:05 ` Daniel Vetter
2021-04-28 10:31 ` Christian König
2021-04-28 12:21 ` Daniel Vetter
2021-04-28 12:26 ` Daniel Vetter
2021-04-28 13:11 ` Christian König
2021-04-28 13:34 ` Daniel Vetter
2021-04-28 13:37 ` Christian König
2021-04-28 14:34 ` Daniel Vetter
2021-04-28 14:45 ` Christian König
2021-04-29 11:07 ` Daniel Vetter
2021-04-28 20:39 ` Alex Deucher
2021-04-29 11:12 ` Daniel Vetter
2021-04-30 8:58 ` Daniel Vetter
2021-04-30 9:07 ` Christian König
2021-04-30 9:35 ` Daniel Vetter
2021-04-30 10:17 ` Daniel Stone
2021-04-28 12:45 ` Simon Ser
2021-04-28 13:03 ` Alex Deucher
2021-04-27 19:41 ` Jason Ekstrand
2021-04-27 21:58 ` Marek Olšák
2021-04-28 4:01 ` Jason Ekstrand
2021-04-28 5:19 ` Marek Olšák
2021-04-27 18:38 ` Dave Airlie
2021-04-27 19:23 ` Marek Olšák
2021-04-28 6:59 ` Christian König
2021-04-28 9:07 ` Michel Dänzer
2021-04-28 9:57 ` Daniel Vetter
2021-05-01 22:27 ` Marek Olšák
2021-05-03 14:42 ` Alex Deucher
2021-05-03 14:59 ` Jason Ekstrand
2021-05-03 15:03 ` Christian König
2021-05-03 15:15 ` Jason Ekstrand
2021-05-03 15:16 ` Bas Nieuwenhuizen
2021-05-03 15:23 ` Jason Ekstrand
2021-05-03 20:36 ` Marek Olšák
2021-05-04 3:11 ` Marek Olšák
2021-05-04 7:01 ` Christian König
2021-05-04 7:32 ` Daniel Vetter
2021-05-04 8:09 ` Christian König
2021-05-04 8:27 ` Daniel Vetter
2021-05-04 9:14 ` Christian König
2021-05-04 9:47 ` Daniel Vetter
2021-05-04 10:53 ` Christian König
2021-05-04 11:13 ` Daniel Vetter
2021-05-04 12:48 ` Christian König
2021-05-04 16:44 ` Daniel Vetter
2021-05-04 17:16 ` Marek Olšák
2021-05-04 21:06 ` Jason Ekstrand
2021-04-28 9:54 ` Daniel Vetter [this message]
2021-04-27 20:49 ` Jason Ekstrand
2021-04-27 12:12 ` Daniel Vetter
2021-04-20 19:16 ` Jason Ekstrand
2021-04-20 19:27 ` Daniel Vetter
2021-04-20 14:53 ` Daniel Stone
2021-04-20 14:58 ` [Mesa-dev] " Christian König
2021-04-20 15:07 ` Daniel Stone
2021-04-20 15:16 ` Christian König
2021-04-20 15:49 ` Daniel Stone
2021-04-20 16:25 ` Marek Olšák
2021-04-20 16:42 ` Jacob Lifshay
2021-04-20 18:03 ` Daniel Stone
2021-04-20 18:39 ` Daniel Vetter
2021-04-20 19:20 ` Marek Olšák
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=YIkwwD1z7r4BbEZU@phenom.ffwll.local \
--to=daniel@ffwll.ch \
--cc=ckoenig.leichtzumerken@gmail.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=maraeo@gmail.com \
--cc=mesa-dev@lists.freedesktop.org \
/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 NNTP newsgroup(s).