From: "Christian König" <deathsimple@vodafone.de>
To: "Michel Dänzer" <michel@daenzer.net>
Cc: mesa-dev@lists.freedesktop.org, dri-devel@lists.freedesktop.org
Subject: Re: [PATCH 2/2] r600g/radeonsi: Prefer VRAM for CPU -> GPU streaming buffers
Date: Thu, 31 Jul 2014 12:06:29 +0200 [thread overview]
Message-ID: <53DA1525.4020904@vodafone.de> (raw)
In-Reply-To: <53DA1325.3020301@daenzer.net>
Am 31.07.2014 um 11:57 schrieb Michel Dänzer:
> On 31.07.2014 18:52, Christian König wrote:
>> Am 31.07.2014 um 11:43 schrieb Michel Dänzer:
>>> From: Michel Dänzer <michel.daenzer@amd.com>
>>>
>>> Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
>> At least for PIPE_USAGE_STREAM buffers that's a bad idea, cause they are
>> used by VDPAU to read back to data to a CPU buffer and that's really
>> slow from VRAM.
> From src/gallium/docs/source/screen.rst:
>
> * ``PIPE_USAGE_DEFAULT``: Optimized for fast GPU access.
> * ``PIPE_USAGE_IMMUTABLE``: Optimized for fast GPU access and the resource is
> not expected to be mapped or changed (even by the GPU) after the first upload.
> * ``PIPE_USAGE_DYNAMIC``: Expect frequent write-only CPU access. What is
> uploaded is expected to be used at least several times by the GPU.
> * ``PIPE_USAGE_STREAM``: Expect frequent write-only CPU access. What is
> uploaded is expected to be used only once by the GPU.
> * ``PIPE_USAGE_STAGING``: Optimized for fast CPU access.
>
> That reads to me like only PIPE_USAGE_STAGING is expected to provide fast
> CPU reads.
Forget what I've wrote, we do this handling by letting the driver copy
the bitmap content to a staging texture. All other use case indeed use
PIPE_USAGE_STAGING.
Christian.
_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/mesa-dev
next prev parent reply other threads:[~2014-07-31 10:06 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-31 9:43 [PATCH 0/2] radeon: Allow streaming data from CPU to GPU via VRAM Michel Dänzer
2014-07-31 9:43 ` [PATCH 1/2] drm/radeon: s/ioctl_wait_idle/mmio_hpd_flush/ Michel Dänzer
2014-07-31 18:39 ` Alex Deucher
2014-07-31 9:43 ` [PATCH 2/2] drm/radeon: Always flush the HDP cache before submitting a CS to the GPU Michel Dänzer
2014-07-31 9:43 ` [PATCH 1/2] r600g/radeonsi: Reduce or even drop special treatment of persistent mappings Michel Dänzer
2014-07-31 17:36 ` Marek Olšák
2014-07-31 9:43 ` [PATCH 2/2] r600g/radeonsi: Prefer VRAM for CPU -> GPU streaming buffers Michel Dänzer
2014-07-31 9:52 ` Christian König
2014-07-31 9:57 ` Michel Dänzer
2014-07-31 10:06 ` Christian König [this message]
2014-07-31 17:40 ` 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=53DA1525.4020904@vodafone.de \
--to=deathsimple@vodafone.de \
--cc=dri-devel@lists.freedesktop.org \
--cc=mesa-dev@lists.freedesktop.org \
--cc=michel@daenzer.net \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.