ION: Sys_heap: Add cached pool to spead up cached buffer alloc

Add ion cached pool in system heap. This patch add a cached pool
in system heap. It has a great improvement of alloc for cached
buffer.

With memory pressue alloc test 800MB in userspace used iontest.
The result avg is 577ms. Without patch it's avg is about 883ms.

v1: Makes the cached buffer zeroed before going to pool
v2: Add cached param in pool to distinguish wheather need to flush
    cache at a fresh alloc.
    Rework the shrink function.

Signed-off-by: Chen Feng <puck.chen@hisilicon.com>
Signed-off-by: Xia  Qing <saberlily.xia@hisilicon.com>
Reviewed-by: Fu Jun <oliver.fu@hisilicon.com>
Acked-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 7 insertions, 3 deletions

diff --git a/drivers/staging/android/ion/ion_page_pool.c b/drivers/staging/android/ion/ion_page_pool.c
index 1fe8016..2c5e5c5 100644
--- a/drivers/staging/android/ion/ion_page_pool.c
+++ b/drivers/staging/android/ion/ion_page_pool.c
@@ -30,8 +30,9 @@ static void *ion_page_pool_alloc_pages(struct ion_page_pool *pool)
 
 	if (!page)
 		return NULL;
-	ion_pages_sync_for_device(NULL, page, PAGE_SIZE << pool->order,
-						DMA_BIDIRECTIONAL);
+	if (!pool->cached)
+		ion_pages_sync_for_device(NULL, page, PAGE_SIZE << pool->order,
+					  DMA_BIDIRECTIONAL);
 	return page;
 }
 
@@ -147,7 +148,8 @@ int ion_page_pool_shrink(struct ion_page_pool *pool, gfp_t gfp_mask,
 	return freed;
 }
 
-struct ion_page_pool *ion_page_pool_create(gfp_t gfp_mask, unsigned int order)
+struct ion_page_pool *ion_page_pool_create(gfp_t gfp_mask, unsigned int order,
+					   bool cached)
 {
 	struct ion_page_pool *pool = kmalloc(sizeof(*pool), GFP_KERNEL);
 
@@ -161,6 +163,8 @@ struct ion_page_pool *ion_page_pool_create(gfp_t gfp_mask, unsigned int order)
 	pool->order = order;
 	mutex_init(&pool->mutex);
 	plist_node_init(&pool->list, order);
+	if (cached)
+		pool->cached = true;
 
 	return pool;
 }