diff options
| author | Alexander Gordeev | 2015-06-03 08:18:28 +0200 |
|---|---|---|
| committer | Paul E. McKenney | 2015-07-15 14:45:18 -0700 |
| commit | 05b84aec465c34da242a224d2438d192ca0feec7 (patch) | |
| tree | 4dc8cca8a45e4bea1eb40f71ad42c7325c6b6069 | |
| parent | a6d77081e266605c9f4d8c11e0ee00468b9dc614 (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>
| -rw-r--r-- | kernel/rcu/tree.c | 12 | ||||
| -rw-r--r-- | kernel/rcu/tree.h | 2 |
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 */ |