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authorAlexander Gordeev <agordeev@redhat.com>2015-06-03 08:18:28 +0200
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2015-07-15 14:45:18 -0700
commit05b84aec465c34da242a224d2438d192ca0feec7 (patch)
tree4dc8cca8a45e4bea1eb40f71ad42c7325c6b6069 /kernel/rcu
parenta6d77081e266605c9f4d8c11e0ee00468b9dc614 (diff)
rcu: Limit rcu_capacity[] size to RCU_NUM_LVLS items
Number of items in rcu_capacity[] array is defined by macro MAX_RCU_LVLS. However, that array is never accessed beyond RCU_NUM_LVLS index. Therefore, we can limit the array to RCU_NUM_LVLS items and eliminate MAX_RCU_LVLS. As result, in most cases the memory is conserved. Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/tree.c12
-rw-r--r--kernel/rcu/tree.h2
2 files changed, 6 insertions, 8 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 2103beedb49f..2ec7b796f660 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3998,19 +3998,19 @@ static void __init rcu_init_one(struct rcu_state *rsp,
"rcu_node_0",
"rcu_node_1",
"rcu_node_2",
- "rcu_node_3" }; /* Match MAX_RCU_LVLS */
+ "rcu_node_3" };
static const char * const fqs[] = {
"rcu_node_fqs_0",
"rcu_node_fqs_1",
"rcu_node_fqs_2",
- "rcu_node_fqs_3" }; /* Match MAX_RCU_LVLS */
+ "rcu_node_fqs_3" };
static u8 fl_mask = 0x1;
int cpustride = 1;
int i;
int j;
struct rcu_node *rnp;
- BUILD_BUG_ON(MAX_RCU_LVLS > ARRAY_SIZE(buf)); /* Fix buf[] init! */
+ BUILD_BUG_ON(RCU_NUM_LVLS > ARRAY_SIZE(buf)); /* Fix buf[] init! */
/* Silence gcc 4.8 false positive about array index out of range. */
if (rcu_num_lvls <= 0 || rcu_num_lvls > RCU_NUM_LVLS)
@@ -4082,7 +4082,7 @@ static void __init rcu_init_geometry(void)
{
ulong d;
int i;
- int rcu_capacity[MAX_RCU_LVLS];
+ int rcu_capacity[RCU_NUM_LVLS];
/*
* Initialize any unspecified boot parameters.
@@ -4122,14 +4122,14 @@ static void __init rcu_init_geometry(void)
* with the given number of levels.
*/
rcu_capacity[0] = rcu_fanout_leaf;
- for (i = 1; i < MAX_RCU_LVLS; i++)
+ for (i = 1; i < RCU_NUM_LVLS; i++)
rcu_capacity[i] = rcu_capacity[i - 1] * RCU_FANOUT;
/*
* The tree must be able to accommodate the configured number of CPUs.
* If this limit is exceeded than we have a serious problem elsewhere.
*/
- if (nr_cpu_ids > rcu_capacity[MAX_RCU_LVLS - 1])
+ if (nr_cpu_ids > rcu_capacity[RCU_NUM_LVLS - 1])
panic("rcu_init_geometry: rcu_capacity[] is too small");
/* Calculate the number of levels in the tree. */
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index a6faae53ea8f..d625e9ff0faf 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -36,8 +36,6 @@
* Of course, your mileage may vary.
*/
-#define MAX_RCU_LVLS 4
-
#ifdef CONFIG_RCU_FANOUT
#define RCU_FANOUT CONFIG_RCU_FANOUT
#else /* #ifdef CONFIG_RCU_FANOUT */