ion: move shrinker out of heaps

Every heap that uses deferred frees is going to need a shrinker
to shrink the freelist under memory pressure.  Rather than
requiring each heap to implement a shrinker, automatically
register a shrinker if the deferred free flag is set.
The system heap also needs to shrink its page pools, so add
a shrink function to the heap ops that will be called after
shrinking the freelists.

Change-Id: Icda722d683426fadb8ddd1c8e9499264ab682c57
Signed-off-by: Colin Cross <ccross@android.com>

1 files changed, 1 insertions, 6 deletions

diff --git a/drivers/staging/android/ion/ion_page_pool.c b/drivers/staging/android/ion/ion_page_pool.c
index f087a02770a..0e20e62ec4b 100644
--- a/drivers/staging/android/ion/ion_page_pool.c
+++ b/drivers/staging/android/ion/ion_page_pool.c
@@ -130,15 +130,11 @@ static int ion_page_pool_total(struct ion_page_pool *pool, bool high)
 int ion_page_pool_shrink(struct ion_page_pool *pool, gfp_t gfp_mask,
 				int nr_to_scan)
 {
-	int nr_freed = 0;
 	int i;
 	bool high;
 
 	high = !!(gfp_mask & __GFP_HIGHMEM);
 
-	if (nr_to_scan == 0)
-		return ion_page_pool_total(pool, high);
-
 	for (i = 0; i < nr_to_scan; i++) {
 		struct page *page;
 
@@ -153,10 +149,9 @@ int ion_page_pool_shrink(struct ion_page_pool *pool, gfp_t gfp_mask,
 		}
 		mutex_unlock(&pool->mutex);
 		ion_page_pool_free_pages(pool, page);
-		nr_freed += (1 << pool->order);
 	}
 
-	return nr_freed;
+	return ion_page_pool_total(pool, high);
 }
 
 struct ion_page_pool *ion_page_pool_create(gfp_t gfp_mask, unsigned int order)