Re: [Dri-devel] DRM locks usage?

[Thomas <uni...@sh...>]

> Thomas Hellstr=F6m wrote:
>> Hi!
>>
>> Is it possible to use the heavyweight drm locking mechanisms for other
>> locks than the global hardware lock?
>>
>> What I'm after is a mechanism to suspend drm-aware processes until a
>> display resource gets available and then wake them up on a FIFO basis
>> when
>> the process that currently holds the resource signals it's availabilit=
y.
>> Typically processes hold the resource for at least 10 ms, so the globa=
l
>> lock is not an option; spinlocks are too cpu-consuming.
>>
>> I was wondering if one could implement a second lock struct in the
>> private
>> part of the SAREA and then use a drm IOCTL on that one, but briefly
>> browsing the headers I see no way to pass a private lock to the DRM?
>>
>> Any help would be greatly appreciated.
>
> You should look at the way vblank interrupt waiting is handled in the
> radeon driver.  That works by just having the calling process block in
> an ioctl.  The other way to do it would be by using a standard futex.
> Either should work.
>


Thanks! A futex was exactly what I was looking for.
/Thomas