On Thu, Dec 24, 2015 at 07:54:09PM +0530, Goel, Akash wrote: > > > On 12/24/2015 5:52 PM, Chris Wilson wrote: > >On Thu, Dec 24, 2015 at 04:16:08PM +0530, Praveen Paneri wrote: > >>When the system is running low on memory, gem shrinker is invoked. > >>In this process objects will be unbounded from GTT and unbinding process > >>will require access to GTT(GTTADR) and also to fence register potentially. > >>That requires a resume of gfx device, if suspended, in the shrinker path. > >>Considering the power leakage due to intermediate resume, perform unbinding > >>operation only if device is already runtime active. > >> > >>Signed-off-by: Akash Goel <akash.goel@xxxxxxxxx> > >>Signed-off-by: Praveen Paneri <praveen.paneri@xxxxxxxxx> > >>Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > > >Lgtm, the only complication is that we over report the number of > >shrinkable objects. But that isn't such a big issue with the current > >incarnation of the shrinker. > > > >>--- > >> drivers/gpu/drm/i915/i915_gem_shrinker.c | 11 +++++++++++ > >> 1 file changed, 11 insertions(+) > >> > >>diff --git a/drivers/gpu/drm/i915/i915_gem_shrinker.c b/drivers/gpu/drm/i915/i915_gem_shrinker.c > >>index f7df54a..89350f4 100644 > >>--- a/drivers/gpu/drm/i915/i915_gem_shrinker.c > >>+++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c > >>@@ -89,6 +89,15 @@ i915_gem_shrink(struct drm_i915_private *dev_priv, > >> i915_gem_retire_requests(dev_priv->dev); > >> > >> /* > >>+ * Unbinding of objects will require HW access. Lets not wake > >>+ * up gfx device just for this. Do the unbinding only if gfx > >>+ * device is already active. > >>+ */ > >>+ if ((flags & I915_SHRINK_BOUND) && > >>+ !intel_runtime_pm_get_noidle(dev_priv)) > > > >Please line up contnuation lines with the opening bracking, hint cino=:0,(0 for vim. > > > >With the whitespace fixed, > >Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > > >/* Unbinding of objects will require HW access; let us not wake up > > * the device just to recover a little memory. If absolutely necessary, > > * we will force the wake during oom-notifier. > > */ > > Sorry not fully sure but do we need to cover > i915_gem_retire_requests() also ? No. That is covered by the dev_priv->mm.busy wakeref. > Actually retire_requests could also lead to a potential unbinding, > if the last reference of a context goes away in that. Indeed, also last object unreference could trigger an unbinding, and even last vma use. All covered by the dev_priv->mm.busy wakeref held whilst there are any requests in flight. > There is a runtime_pm_get protection in i915_gem_free_object, so > should not be a problem for ringbuffer & context image objects and > most probably the i915_gem_context_clean would get completed before > the device again goes into runtime suspend state. No the one in i915_gem_free_object is actually wrong (granularity), and hopefully will be fixed in the near future. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
