[Intel-gfx] [PATCH v2] drm/i915: Retire before attempting to evict from the active lists

[Chris Wilson]

On Mon, Dec 12, 2016 at 11:58:24AM +0000, Tvrtko Ursulin wrote:
> 
> On 09/12/2016 15:05, Chris Wilson wrote:
> >Some object retain an extra pin whilst they are active (e.g. contexts).
> >This excludes them from being considered for eviction unless we idle the
> >GPU. If before we look at the active list, before we retire we can
> >hopefully remove a few excess pins and reduce the amount of searching
> >required.
> >
> >v2: Similar principle applies to evict_for_vma
> >
> >Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> >---
> > drivers/gpu/drm/i915/i915_gem_evict.c | 17 ++++++++++++++++-
> > 1 file changed, 16 insertions(+), 1 deletion(-)
> >
> >diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c
> >index a3f7f1ca6f21..689338e22ba8 100644
> >--- a/drivers/gpu/drm/i915/i915_gem_evict.c
> >+++ b/drivers/gpu/drm/i915/i915_gem_evict.c
> >@@ -130,7 +130,14 @@ i915_gem_evict_something(struct i915_address_space *vm,
> > 				    start, end,
> > 				    flags & PIN_HIGH ? DRM_MM_INSERT_HIGH : 0);
> >
> >-	if (flags & PIN_NONBLOCK)
> >+	/* Retire before we search the active list. Although we have
> >+	 * reasonable accuracy in our retirement lists, we may have
> >+	 * a stray pin (preventing eviction) that can only be resolved by
> >+	 * retiring.
> >+	 */
> >+	if (!(flags & PIN_NONBLOCK))
> >+		i915_gem_retire_requests(dev_priv);
> >+	else
> > 		phases[1] = NULL;
> >
> > search_again:
> >@@ -236,6 +243,14 @@ int i915_gem_evict_for_vma(struct i915_vma *target, unsigned int flags)
> > 	lockdep_assert_held(&target->vm->i915->drm.struct_mutex);
> > 	trace_i915_gem_evict_vma(target, flags);
> >
> >+	/* Retire before we search the active list. Although we have
> >+	 * reasonable accuracy in our retirement lists, we may have
> >+	 * a stray pin (preventing eviction) that can only be resolved by
> >+	 * retiring.
> >+	 */
> >+	if (!(flags & PIN_NONBLOCK))
> >+		i915_gem_retire_requests(target->vm->i915);
> >+
> > 	check_color = target->vm->mm.color_adjust;
> > 	if (check_color) {
> > 		/* Expand search to cover neighbouring guard pages (or lack!) */
> >
> 
> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Ta, pushed a while back.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre