Hi folks,

We are using an OSD framebuffer allocated with dma_alloc_coherent(),
mmap()ing it to userspace and doing stuff like software alpha blending.
The buffer is double-sized and we do pan() stuff to implement
double-buffering.

The userspace app is taking a lot of cpu (in userspace, not system)
which I suspect may be to do with lots of small reads and writes to this
uncached memory.

I'd like to have write-back caching on for this buffer and explicitly
flush it in the swap-buffer routine.

Are there some functions I can call on the buffer I got from
dma_alloc_coherent to turn cache back on and do this?

Or should I be allocating the buffer some other way?

Thanks,

-- 
Jon Povey
[email protected]

 
Racelogic is a limited company registered in England. Registered number 2743719 
. 
Registered Office Unit 10, Swan Business Centre, Osier Way, Buckingham, Bucks, 
MK18 1TB .
The information contained in this electronic mail transmission is intended by 
Racelogic Ltd for the use of the named individual or entity to which it is 
directed and may contain information that is confidential or privileged. If you 
have received this electronic mail transmission in error, please delete it from 
your system without copying or forwarding it, and notify the sender of the 
error by reply email so that the sender's address records can be corrected. The 
views expressed by the sender of this communication do not necessarily 
represent those of Racelogic Ltd. Please note that Racelogic reserves the right 
to monitor e-mail communications passing through its network
_______________________________________________
Davinci-linux-open-source mailing list
[email protected]
http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source

Reply via email to