[PATCH] fixes to drm-next - TTM DMA code (v1)
thellstrom at vmware.com
Mon Dec 19 11:51:15 PST 2011
On 12/13/2011 05:40 PM, Konrad Rzeszutek Wilk wrote:
> On Tue, Dec 13, 2011 at 05:23:30PM +0100, Thomas Hellstrom wrote:
>> On 12/13/2011 05:07 PM, Jerome Glisse wrote:
>>> On Mon, Dec 12, 2011 at 03:09:26PM -0500, Konrad Rzeszutek Wilk wrote:
>>>> Jerome pointed me to some accounting error in the DMA API debugging code and
>>>> while I can't figure it out yet, I did notice some extreme slowness - which
>>>> is due to the nouveau driver calling the unpopulate (now that unbind +
>>>> unpopulate are squashed) quite a lot (this is using Gnome Shell - I think GNOME2
>>>> did not have those issues but I can't recall).
>>>> Anyhow these patches fix the 50% perf regression I saw and also some minor bugs
>>>> that I noticed.
>>> Gonna review those today and test them.
>> I'm not whether any drivers are still using the AGP backend?
> Uh, probably they do if the cards are AGP?
> The problem I encountered was with an PCIe Nvidia card:
> 01:00.0 VGA compatible controller: nVidia Corporation G84 [GeForce 8600 GT] (rev a1
>> Calling unpopulate / (previous clear) each time unbind is done
>> should be quite
>> inefficient with that one, as AGP sets up its own data structures
>> and copies page tables
>> on each populate. That should really be avoided unless there is a
>> good reason to have it.
> nouveau_bo_rd32 and nv50_crtc_cursor_set showed up as the callers that
> were causing the unpopulate calls. It did happen _a lot_ when I moved the
> cursor madly.
Was there a resolution to this. If the ttm_tt rewrite results in
unpopulate being called more often than before,
and that causes performance regressions, that must be fixed as soon as
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
More information about the dri-devel