On Fri, Aug 29, 2014 at 03:11:19PM +0200, David Herrmann wrote:
Hi
On Fri, Aug 29, 2014 at 3:10 PM, Thierry Reding thierry.reding@gmail.com wrote:
On Fri, Aug 29, 2014 at 02:01:00PM +0200, David Herrmann wrote:
There is no reason to use a heavy mutex for idr protection. Use a spinlock and make idr-allocation use idr_preload().
This patch also makes mode-object lookup irq-save, in case you ever wanna lookup modeset objects from interrupts. This is just a side-effect of avoiding a mutex.
I don't think that's entirely accurate. idr_preload(GFP_KERNEL) might sleep since GFP_KERNEL & __GFP_WAIT != 0.
idr_preload() is only used in registration, not in lookups. Not sure what you refer to?
Yes, you're right. I wasn't paying close enough attention and somehow applied "makes irq-safe" to the "idr_preload()" change without relating it to "lookup".
Thierry