drn/i915: Break up long i915_buddy_free_list() with a cond_resched()

In the selftests, we may feed very long lists of blocks to be freed on
culmination of the tests. This coupled with kasan and other
malloc-tracing can make the kmem_cache_free() operation time consuming,
and doing many of those trigger soft lockup warnings. Break the list up
with a cond_resched().

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221144917.1040662-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_buddy.c b/drivers/gpu/drm/i915/i915_buddy.c
index e9d4200ce3bc69fcdd68fd8e9b858b38566bfb68..66883af64ca113fafea3fbbd6404326290628607 100644 (file)
--- a/drivers/gpu/drm/i915/i915_buddy.c
+++ b/drivers/gpu/drm/i915/i915_buddy.c
@@ -262,8 +262,10 @@ void i915_buddy_free_list(struct i915_buddy_mm *mm, struct list_head *objects)
 {
        struct i915_buddy_block *block, *on;
 
-       list_for_each_entry_safe(block, on, objects, link)
+       list_for_each_entry_safe(block, on, objects, link) {
                i915_buddy_free(mm, block);
+               cond_resched();
+       }
        INIT_LIST_HEAD(objects);
 }