[Intel-gfx] [PATCH 06/66] drm/i915: Export a preallocate variant of i915_active_acquire()

[Chris Wilson]

Quoting Tvrtko Ursulin (2020-07-17 13:21:54)
> 
> On 15/07/2020 12:50, Chris Wilson wrote:
> > Sometimes we have to be very careful not to allocate underneath a mutex
> > (or spinlock) and yet still want to track activity. Enter
> > i915_active_acquire_for_context(). This raises the activity counter on
> > i915_active prior to use and ensures that the fence-tree contains a slot
> > for the context.
> 
> Changelog?

"Time spent with perf trying to reduce holdtime of certain mutexes we
will introduce, in particular focusing on reducing the number of atomics
required for typical i915_active lookups"
-Chris