Skip to contentSkip to conversation

memcg: remove some redundant checks

PATCH In review Li Zefan 2 participants 2 messages May 22, 2009

Subsystems (2)
lore
Share & tools
lore

Li Zefan

author
#0 lore raw

PATCH 1/1 memcg: remove some redundant checks

We don't need to check do_swap_account in the case that the function which checks do_swap_account will never get called if do_swap_account == 0.

---
 memcontrol.c  |   11 ++++-------
 page_cgroup.c |    8 --------
 2 files changed, 4 insertions(+), 15 deletions(-)
mm/memcontrol.c +4 -7
@@ -45,7 +45,7 @@ struct cgroup_subsys mem_cgroup_subsys _
 #define MEM_CGROUP_RECLAIM_RETRIES	5
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
-/* Turned on only when memory cgroup is enabled && really_do_swap_account = 0 */
+/* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
 int do_swap_account __read_mostly;
 static int really_do_swap_account __initdata = 1; /* for remember boot option*/
 #else
@@ -1771,16 +1771,14 @@ static int mem_cgroup_resize_limit(struc
 	return ret;
 }
 
-int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
-				unsigned long long val)
+static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
+					unsigned long long val)
 {
 	int retry_count;
 	u64 memlimit, oldusage, curusage;
 	int children = mem_cgroup_count_children(memcg);
 	int ret = -EBUSY;
 
-	if (!do_swap_account)
-		return -EINVAL;
 	/* see mem_cgroup_resize_res_limit */
  	retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
 	oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
@@ -2015,8 +2013,7 @@ static u64 mem_cgroup_read(struct cgroup
 		val = res_counter_read_u64(&mem->res, name);
 		break;
 	case _MEMSWAP:
-		if (do_swap_account)
-			val = res_counter_read_u64(&mem->memsw, name);
+		val = res_counter_read_u64(&mem->memsw, name);
 		break;
 	default:
 		BUG();
mm/page_cgroup.c +0 -8
@@ -316,8 +316,6 @@ static int swap_cgroup_prepare(int type)
 	struct swap_cgroup_ctrl *ctrl;
 	unsigned long idx, max;
 
-	if (!do_swap_account)
-		return 0;
 	ctrl = &swap_cgroup_ctrl[type];
 
 	for (idx = 0; idx < ctrl->length; idx++) {
@@ -354,9 +352,6 @@ unsigned short swap_cgroup_record(swp_en
 	struct swap_cgroup *sc;
 	unsigned short old;
 
-	if (!do_swap_account)
-		return 0;
-
 	ctrl = &swap_cgroup_ctrl[type];
 
 	mappage = ctrl->map[idx];
@@ -385,9 +380,6 @@ unsigned short lookup_swap_cgroup(swp_en
 	struct swap_cgroup *sc;
 	unsigned short ret;
 
-	if (!do_swap_account)
-		return 0;
-
 	ctrl = &swap_cgroup_ctrl[type];
 	mappage = ctrl->map[idx];
 	sc = page_address(mappage);

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to [email protected]. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"[email protected]"> [email protected] </a>

Acked-by on v1 1/1
#1 lore raw
Quoted 5 lines · On Fri, 22 May 2009 14:27:24 +0800 Li Zefan <[email protected]> wrote:

We don't need to check do_swap_account in the case that the function which checks do_swap_account will never get called if do_swap_account == 0.

Exactly. thanks.

Quoted 77 lines
---
 memcontrol.c  |   11 ++++-------
 page_cgroup.c |    8 --------
 2 files changed, 4 insertions(+), 15 deletions(-)
mm/memcontrol.c +4 -7
@@ -45,7 +45,7 @@ struct cgroup_subsys mem_cgroup_subsys _
 #define MEM_CGROUP_RECLAIM_RETRIES	5
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
-/* Turned on only when memory cgroup is enabled && really_do_swap_account = 0 */
+/* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
 int do_swap_account __read_mostly;
 static int really_do_swap_account __initdata = 1; /* for remember boot option*/
 #else
@@ -1771,16 +1771,14 @@ static int mem_cgroup_resize_limit(struc
 	return ret;
 }
 
-int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
-				unsigned long long val)
+static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
+					unsigned long long val)
 {
 	int retry_count;
 	u64 memlimit, oldusage, curusage;
 	int children = mem_cgroup_count_children(memcg);
 	int ret = -EBUSY;
 
-	if (!do_swap_account)
-		return -EINVAL;
 	/* see mem_cgroup_resize_res_limit */
  	retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
 	oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
@@ -2015,8 +2013,7 @@ static u64 mem_cgroup_read(struct cgroup
 		val = res_counter_read_u64(&mem->res, name);
 		break;
 	case _MEMSWAP:
-		if (do_swap_account)
-			val = res_counter_read_u64(&mem->memsw, name);
+		val = res_counter_read_u64(&mem->memsw, name);
 		break;
 	default:
 		BUG();
mm/page_cgroup.c +0 -9
@@ -316,8 +316,6 @@ static int swap_cgroup_prepare(int type)
 	struct swap_cgroup_ctrl *ctrl;
 	unsigned long idx, max;
 
-	if (!do_swap_account)
-		return 0;
 	ctrl = &swap_cgroup_ctrl[type];
 
 	for (idx = 0; idx < ctrl->length; idx++) {
@@ -354,9 +352,6 @@ unsigned short swap_cgroup_record(swp_en
 	struct swap_cgroup *sc;
 	unsigned short old;
 
-	if (!do_swap_account)
-		return 0;
-
 	ctrl = &swap_cgroup_ctrl[type];
 
 	mappage = ctrl->map[idx];
@@ -385,9 +380,6 @@ unsigned short lookup_swap_cgroup(swp_en
 	struct swap_cgroup *sc;
 	unsigned short ret;
 
-	if (!do_swap_account)
-		return 0;
-
 	ctrl = &swap_cgroup_ctrl[type];
 	mappage = ctrl->map[idx];
 	sc = page_address(mappage);
--
Quoted 5 lines

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to [email protected]. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"[email protected]"> [email protected] </a>