[PATCHv2 1/3] staging: ion: shrink page-pool by page unit

From: Gioh Kim
Date: Wed Oct 29 2014 - 01:35:20 EST


This patch shrink page-pool by page unit.

Shrinker usually get the pool size with the pool-scanner
and pass the size to the pool-counter to shrink entire pool.
But the pool-scanner is working in block unit.
and pool-counter page unit.
So it is confused.

Change-Id: If25c693c09f6ebd14c87809feddb72f9058e8308
Signed-off-by: Gioh Kim <gioh.kim@xxxxxxx>
---
drivers/staging/android/ion/ion_page_pool.c | 5 +++--
drivers/staging/android/ion/ion_system_heap.c | 18 +++++++++++++++---
2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/android/ion/ion_page_pool.c b/drivers/staging/android/ion/ion_page_pool.c
index 5864f3d..165152f 100644
--- a/drivers/staging/android/ion/ion_page_pool.c
+++ b/drivers/staging/android/ion/ion_page_pool.c
@@ -116,7 +116,7 @@ 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 freed;
+ int freed = 0;
bool high;

if (current_is_kswapd())
@@ -127,7 +127,7 @@ int ion_page_pool_shrink(struct ion_page_pool *pool, gfp_t gfp_mask,
if (nr_to_scan == 0)
return ion_page_pool_total(pool, high);

- for (freed = 0; freed < nr_to_scan; freed++) {
+ while (freed <= nr_to_scan) {
struct page *page;

mutex_lock(&pool->mutex);
@@ -141,6 +141,7 @@ 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);
+ freed += (1 << pool->order);
}

return freed;
diff --git a/drivers/staging/android/ion/ion_system_heap.c b/drivers/staging/android/ion/ion_system_heap.c
index da2a63c..0ba8aaf 100644
--- a/drivers/staging/android/ion/ion_system_heap.c
+++ b/drivers/staging/android/ion/ion_system_heap.c
@@ -29,7 +29,7 @@
static gfp_t high_order_gfp_flags = (GFP_HIGHUSER | __GFP_ZERO | __GFP_NOWARN |
__GFP_NORETRY) & ~__GFP_WAIT;
static gfp_t low_order_gfp_flags = (GFP_HIGHUSER | __GFP_ZERO | __GFP_NOWARN);
-static const unsigned int orders[] = {8, 4, 0};
+static const unsigned int orders[] = {8, 6, 4, 0};
static const int num_orders = ARRAY_SIZE(orders);
static int order_to_index(unsigned int order)
{
@@ -212,14 +212,26 @@ static int ion_system_heap_shrink(struct ion_heap *heap, gfp_t gfp_mask,
{
struct ion_system_heap *sys_heap;
int nr_total = 0;
- int i;
+ int i, nr_freed;
+ int only_scan = 0;

sys_heap = container_of(heap, struct ion_system_heap, heap);

+ if (!nr_to_scan)
+ only_scan = 1;
+
for (i = 0; i < num_orders; i++) {
struct ion_page_pool *pool = sys_heap->pools[i];

- nr_total += ion_page_pool_shrink(pool, gfp_mask, nr_to_scan);
+ nr_freed = ion_page_pool_shrink(pool, gfp_mask, nr_to_scan);
+ nr_total += nr_freed;
+
+ if (!only_scan) {
+ nr_to_scan -= nr_freed;
+ /* shrink completed */
+ if (nr_to_scan <= 0)
+ break;
+ }
}

return nr_total;
--
1.7.9.5

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