On 06/09/2022 18:46, Ville Syrjala wrote:
From: Ville Syrjälä <[email protected]> On gen3 the selftests are pretty much always tripping this: <4> [383.822424] pci 0000:00:02.0: drm_WARN_ON(dev_priv->mm.shrink_count) <4> [383.822546] WARNING: CPU: 2 PID: 3560 at drivers/gpu/drm/i915/i915_gem.c:1223 i915_gem_cleanup_early+0x96/0xb0 [i915] Looks to be due to the status page object lingering on the purge_list. Call synchronize_rcu() ahead of it to make more sure all objects have been freed. Signed-off-by: Ville Syrjälä <[email protected]> --- drivers/gpu/drm/i915/i915_gem.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 0f49ec9d494a..5b61f7ad6473 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1098,6 +1098,7 @@ void i915_gem_drain_freed_objects(struct drm_i915_private *i915) flush_delayed_work(&i915->bdev.wq); rcu_barrier(); } + synchronize_rcu();
Looks a bit suspicious that a loop would not free all but one last rcu grace would. Definitely fixes the issue in your testing?
Perhaps the fact there is a cond_resched in __i915_gem_free_objects, but then again free count should reflect the state and keep it looping in here..
Regards, Tvrtko
