[PATCH 4.4 04/50] staging: ion : Donnot wakeup kswapd in ion system alloc

From: Greg Kroah-Hartman
Date: Fri Apr 27 2018 - 11:33:00 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Chen Feng <puck.chen@xxxxxxxxxxxxx>

commit 2ef230531ee171a475fc3ddad5516dd7e09a8a77 upstream.

Since ion alloc can be called by userspace,eg gralloc.
When it is called frequently, the efficiency of kswapd is
to low. And the reclaimed memory is too lower. In this way,
the kswapd can use to much cpu resources.

With 3.5GB DMA Zone and 0.5 Normal Zone.

pgsteal_kswapd_dma 9364140
pgsteal_kswapd_normal 7071043
pgscan_kswapd_dma 10428250
pgscan_kswapd_normal 37840094

With this change the reclaim ratio has greatly improved
18.9% -> 72.5%

Signed-off-by: Chen Feng <puck.chen@xxxxxxxxxxxxx>
Signed-off-by: Lu bing <albert.lubing@xxxxxxxxxxxxx>
Reviewed-by: Laura Abbott <labbott@xxxxxxxxxx>
Cc: Greg Hackmann <ghackmann@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/staging/android/ion/ion_system_heap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/staging/android/ion/ion_system_heap.c
+++ b/drivers/staging/android/ion/ion_system_heap.c
@@ -27,7 +27,7 @@
#include "ion_priv.h"

static gfp_t high_order_gfp_flags = (GFP_HIGHUSER | __GFP_ZERO | __GFP_NOWARN |
- __GFP_NORETRY) & ~__GFP_DIRECT_RECLAIM;
+ __GFP_NORETRY) & ~__GFP_RECLAIM;
static gfp_t low_order_gfp_flags = (GFP_HIGHUSER | __GFP_ZERO | __GFP_NOWARN);
static const unsigned int orders[] = {8, 4, 0};
static const int num_orders = ARRAY_SIZE(orders);