[Intel-gfx] [PATCH libdrm] intel: Leak the userptr test bo

[Chris Wilson]

On Fri, Apr 17, 2015 at 11:57:28AM +0100, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> In order to use userptr, the kernel tracks the owner's mm with a
> mmu_notifier. Setting that is very expensive - it involves taking all
> mm_locks and a stop_machine(). This tracking lives only for as long as
> the client is using userptr objects - so if the client allocates then
> frees a userptr in a loop, we will be executing that heavyweight setup
> everytime. To ammoritize this cost, just leak the test bo and the single
> backing page we use for detecting userptr.
> 
> v2: Free the object and memory when bufmgr is destroyed.
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
Reveiwed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre