linux-kernel - [PATCH] ION: Sys_heap: Makes ion buffer always alloc from page pool

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Date:	Thu, 5 May 2016 11:27:48 +0800
From:	Chen Feng <puck.chen@...ilicon.com>
To:	<puck.chen@...ilicon.com>, <yudongbin@...ilicon.com>,
	<labbott@...hat.com>, <gregkh@...uxfoundation.org>,
	<arve@...roid.com>, <riandrews@...roid.com>,
	<paul.gortmaker@...driver.com>, <bmarsh94@...il.com>,
	<devel@...verdev.osuosl.org>, <linux-kernel@...r.kernel.org>
CC:	<suzhuangluan@...ilicon.com>, <dan.zhao@...ilicon.com>,
	<zhaojunmin@...wei.com>, <xuyiping@...ilicon.com>,
	<puck.chen@...mail.com>
Subject: [PATCH] ION: Sys_heap: Makes ion buffer always alloc from page pool

Makes the ion buffer always alloced from page pool, no matter
it's cached or not. In this way, it can improve the efficiency
of it.

Currently, there is no difference from cached or non-cached buffer
for the page pool.

Signed-off-by: Chen Feng <puck.chen@...ilicon.com>
---
 drivers/staging/android/ion/ion_system_heap.c | 19 ++-----------------
 1 file changed, 2 insertions(+), 17 deletions(-)

diff --git a/drivers/staging/android/ion/ion_system_heap.c b/drivers/staging/android/ion/ion_system_heap.c
index b69dfc7..caf11fc 100644
--- a/drivers/staging/android/ion/ion_system_heap.c
+++ b/drivers/staging/android/ion/ion_system_heap.c
@@ -56,24 +56,10 @@ static struct page *alloc_buffer_page(struct ion_system_heap *heap,
 				      struct ion_buffer *buffer,
 				      unsigned long order)
 {
-	bool cached = ion_buffer_cached(buffer);
 	struct ion_page_pool *pool = heap->pools[order_to_index(order)];
 	struct page *page;
 
-	if (!cached) {
-		page = ion_page_pool_alloc(pool);
-	} else {
-		gfp_t gfp_flags = low_order_gfp_flags;
-
-		if (order > 4)
-			gfp_flags = high_order_gfp_flags;
-		page = alloc_pages(gfp_flags | __GFP_COMP, order);
-		if (!page)
-			return NULL;
-		ion_pages_sync_for_device(NULL, page, PAGE_SIZE << order,
-						DMA_BIDIRECTIONAL);
-	}
-
+	page = ion_page_pool_alloc(pool);
 	return page;
 }
 
@@ -81,9 +67,8 @@ static void free_buffer_page(struct ion_system_heap *heap,
 			     struct ion_buffer *buffer, struct page *page)
 {
 	unsigned int order = compound_order(page);
-	bool cached = ion_buffer_cached(buffer);
 
-	if (!cached && !(buffer->private_flags & ION_PRIV_FLAG_SHRINKER_FREE)) {
+	if (!(buffer->private_flags & ION_PRIV_FLAG_SHRINKER_FREE)) {
 		struct ion_page_pool *pool = heap->pools[order_to_index(order)];
 
 		ion_page_pool_free(pool, page);
-- 
1.9.1