On Mon, Nov 09, 2015 at 03:09:18PM +0200, Imre Deak wrote: > Looked through it, it seems only i915_gem_set_tiling() could release > the PTE's without waking up the hardware (if no need to unbind the > object). Otherwise it's true that all callers hold (or should hold) > already an RPM ref. To fix the set tiling case to work after your > optimization we could wake up the HW unconditionally there, use a > no_resume RPM ref+and RPM barrier or a separate new lock for the fault > list. I was suggesting we move to the model where writes through gsm took the rpm reference itself. > > From the rpm point of view, this should improve the success of > > runtime suspend, and reduce wakelocks. > > Yes, seems like a worthy optimization, since I assume struct_mutex can > be held for a long time without the need to wake up the hardware. Admittedly most of the time we hold struct_mutex, the hw will be awake for other reasons. But there are many times where we do take the struct_mutex for 10s (if not 100s!) of milliseconds where the hw is completely idle, and so every chance to reduce usage/contention on struct_mutex is a little victory. > Are you ok to first have the fix I posted and a similar one for > i915_gem_set_tiling()? And then to follow-up with your plan. Yes, adding the extra reference to that ioctl, juggling with the struct_mutex and then moving the rpm reference to where it is required lgtm. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
