On ma, 2016-08-01 at 10:11 +0100, Chris Wilson wrote: > We are motivated to avoid using a bitfield for obj->active for a couple > of reasons. Firstly, we wish to document our lockless read of obj->active > using READ_ONCE inside i915_gem_busy_ioctl() and that requires an > integral type (i.e. not a bitfield). Secondly, gcc produces abysmal code > when presented with a bitfield and that shows up high on the profiles of > request tracking (mainly due to excess memory traffic as it converts > the bitfield to a register and back and generates frequent AGI in the > process). > > v2: BIT, break up a long line in compute the other engines, new paint > for i915_gem_object_is_active (now i915_gem_object_get_active). > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Patch reads much better now, Reviewed-by: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> Regards, Joonas -- Joonas Lahtinen Open Source Technology Center Intel Corporation _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
