From: Chris Wilson Date: Tue, 27 Aug 2019 13:26:31 +0000 (+0100) Subject: drm/i915: Only activate i915_active debugobject once X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f52c6d0df6909a0412c347c8e442acc22ce94747;p=linux.git drm/i915: Only activate i915_active debugobject once The point of debug_object_activate is to mark the first, and only the first, acquisition. The object then remains active until the last release. However, we marked up all successful first acquires even though we allowed concurrent parties to try and acquire the i915_active simultaneously (serialised by the i915_active.mutex). Testcase: igt/gem_mmap_gtt/fault-concurrent Signed-off-by: Chris Wilson Cc: Matthew Auld Reviewed-by: Matthew Auld Link: https://patchwork.freedesktop.org/patch/msgid/20190827132631.18627-1-chris@chris-wilson.co.uk --- diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c index 48e16ad93bbdd..6a447f1d01103 100644 --- a/drivers/gpu/drm/i915/i915_active.c +++ b/drivers/gpu/drm/i915/i915_active.c @@ -92,12 +92,16 @@ static void debug_active_init(struct i915_active *ref) static void debug_active_activate(struct i915_active *ref) { - debug_object_activate(ref, &active_debug_desc); + lockdep_assert_held(&ref->mutex); + if (!atomic_read(&ref->count)) /* before the first inc */ + debug_object_activate(ref, &active_debug_desc); } static void debug_active_deactivate(struct i915_active *ref) { - debug_object_deactivate(ref, &active_debug_desc); + lockdep_assert_held(&ref->mutex); + if (!atomic_read(&ref->count)) /* after the last dec */ + debug_object_deactivate(ref, &active_debug_desc); } static void debug_active_fini(struct i915_active *ref)