drm/i915: Fix up usage of SHRINK_STOP

In

commit 81e49f811404f428a9d9a63295a0c267e802fa12
Author: Glauber Costa <[email protected]>
Date:   Wed Aug 28 10:18:13 2013 +1000

    i915: bail out earlier when shrinker cannot acquire mutex

SHRINK_STOP was added to tell the core shrinker code to bail out and
go to the next shrinker since the i915 shrinker couldn't acquire
required locks. But the SHRINK_STOP return code was added to the
->count_objects callback and not the ->scan_objects callback as it
should have been, resulting in tons of dmesg noise like

shrink_slab: i915_gem_inactive_scan+0x0/0x9c negative objects to delete nr=-xxxxxxxxx

Fix discusssed with Dave Chinner.

References: http://www.spinics.net/lists/intel-gfx/msg33597.html
Reported-by: Knut Petersen <[email protected]>
Cc: Knut Petersen <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Glauber Costa <[email protected]>
Cc: Glauber Costa <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Michal Hocko <[email protected]>
Acked-by: Dave Chinner <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index df9253d890ee1fbb60482066312a46e7701bf2d4..cdfb9da0e4ce944529a329ce29f92d391e19973a 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4800,10 +4800,10 @@ i915_gem_inactive_count(struct shrinker *shrinker, struct shrink_control *sc)
 
        if (!mutex_trylock(&dev->struct_mutex)) {
                if (!mutex_is_locked_by(&dev->struct_mutex, current))
-                       return SHRINK_STOP;
+                       return 0;
 
                if (dev_priv->mm.shrinker_no_lock_stealing)
-                       return SHRINK_STOP;
+                       return 0;
 
                unlock = false;
        }
@@ -4901,10 +4901,10 @@ i915_gem_inactive_scan(struct shrinker *shrinker, struct shrink_control *sc)
 
        if (!mutex_trylock(&dev->struct_mutex)) {
                if (!mutex_is_locked_by(&dev->struct_mutex, current))
-                       return 0;
+                       return SHRINK_STOP;
 
                if (dev_priv->mm.shrinker_no_lock_stealing)
-                       return 0;
+                       return SHRINK_STOP;
 
                unlock = false;
        }