From: Francisco Jerez <currojerez@gmail.com>
To: Thomas Hellstrom <thomas@shipmail.org>
Cc: dri-devel@lists.freedesktop.org
Subject: Re: Nouveau fences?
Date: Sun, 28 Nov 2010 17:11:11 +0100 [thread overview]
Message-ID: <87y68dl97k.fsf@gmail.com> (raw)
In-Reply-To: <87k4jxmta8.fsf@riseup.net> (Francisco Jerez's message of "Sun, 28 Nov 2010 15:12:15 +0100")
[-- Attachment #1.1.1: Type: text/plain, Size: 1839 bytes --]
Francisco Jerez <currojerez@riseup.net> writes:
> Thomas Hellstrom <thomas@shipmail.org> writes:
>
>> Ben,
>>
>> I'm looking at a way to make TTM memory management asynchronous with
>> the CPU. The idea is that you should basically be able to DMA data to
>> and from memory regions without waiting for idle, as long as the GPU
>> has a means to provide operation ordering.
>>
> Sounds good. I guess you're mainly dealing with BO eviction
> synchronization? The only problem I see on our side is that calls to our
> move() hook aren't guaranteed to be carried out in order (because of the
> multiple hardware channels). I'm thinking that move() could be extended
> with an optional sync_obj argument, that way move() would be able to
> make sure that evictions are strictly ordered with respect to the fence
> specified.
>
>> While doing that I looked a bit at the Nouveau fencing. It appears
>> like waiting for fences is polling only (no irq to signal fences)? Is
>> that correct?
>>
> That's right, nvidia hardware has no nice way to schedule a fence-like
> interrupt we could selectively turn on and off around the sync_obj_wait
> hook. There's a bunch of (more or less) chipset-specific hacks that
> could be used to get an equivalent effect, but polling has seemed good
> enough so far (in the typical case we only take the "lazy" path so CPU
> usage is still OK).
>
> Unconditional PFIFO CACHE interrupts might be an option too, but, I'm a
> bit afraid of the PFIFO stalls and useless IRQ storms some applications
> could trigger.
>
Meh, apparently this one couldn't make it through, some spam filter has
decided I'm a spammer for some reason...
>> /Thomas
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/dri-devel
[-- Attachment #1.2: Type: application/pgp-signature, Size: 229 bytes --]
[-- Attachment #2: Type: text/plain, Size: 159 bytes --]
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2010-11-28 16:11 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-28 12:39 Nouveau fences? Thomas Hellstrom
2010-11-28 14:12 ` Francisco Jerez
2010-11-28 16:11 ` Francisco Jerez [this message]
2010-11-28 20:37 ` Thomas Hellstrom
2010-11-28 21:55 ` Francisco Jerez
2010-11-29 7:28 ` Thomas Hellstrom
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=87y68dl97k.fsf@gmail.com \
--to=currojerez@gmail.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=thomas@shipmail.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