diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2017-10-19 07:37:33 +0100 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2017-10-19 13:56:38 +0100 |
| commit | 8bd8181590501bc0bae2b6bd9f38d1371e9413a3 (patch) | |
| tree | 4afadfddb9cc8a6ad2805ce88ae2d0d947ade389 | |
| parent | 2f26cdc0e2e64b1af10e0885a251fbd38e4b2336 (diff) | |
drm/i915: Skip waking the device to service pwrite
If the device is in runtime suspend, resuming takes time and reduces our
powersaving. If this was for a small write into an object, that resume
will take longer than any savings in using the indirect GGTT access to
avoid the cpu cache.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20171019063733.31620-1-chris@chris-wilson.co.uk
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index d699ea3ab80b..026cb52ece0b 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1240,7 +1240,23 @@ i915_gem_gtt_pwrite_fast(struct drm_i915_gem_object *obj, if (ret) return ret; - intel_runtime_pm_get(i915); + if (i915_gem_object_has_struct_page(obj)) { + /* + * Avoid waking the device up if we can fallback, as + * waking/resuming is very slow (worst-case 10-100 ms + * depending on PCI sleeps and our own resume time). + * This easily dwarfs any performance advantage from + * using the cache bypass of indirect GGTT access. + */ + if (!intel_runtime_pm_get_if_in_use(i915)) { + ret = -EFAULT; + goto out_unlock; + } + } else { + /* No backing pages, no fallback, we must force GGTT access */ + intel_runtime_pm_get(i915); + } + vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, PIN_MAPPABLE | PIN_NONFAULT | @@ -1257,7 +1273,7 @@ i915_gem_gtt_pwrite_fast(struct drm_i915_gem_object *obj, if (IS_ERR(vma)) { ret = insert_mappable_node(ggtt, &node, PAGE_SIZE); if (ret) - goto out_unlock; + goto out_rpm; GEM_BUG_ON(!node.allocated); } @@ -1320,8 +1336,9 @@ out_unpin: } else { i915_vma_unpin(vma); } -out_unlock: +out_rpm: intel_runtime_pm_put(i915); +out_unlock: mutex_unlock(&i915->drm.struct_mutex); return ret; } |