This update simplifies rcu_init_geometry() code flow
and makes calculation of the total number of rcu_node
structures more easy to read.
The update relies on the fact num_rcu_lvl[] is never
accessed beyond rcu_num_lvls index by the rest of the
code. Therefore, there is no need initialize the whole
num_rcu_lvl[].
Cc: "Paul E. McKenney" <paul...@linux.vnet.ibm.com>
Signed-off-by: Alexander Gordeev <agord...@redhat.com>
---
kernel/rcu/tree.c | 24 ++++++++++--------------
1 file changed, 10 insertions(+), 14 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 4045163..c7ad0a9 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -4008,7 +4008,6 @@ static void __init rcu_init_geometry(void)
{
ulong d;
int i;
- int j;
int rcu_capacity[MAX_RCU_LVLS + 1];
/*
@@ -4059,24 +4058,21 @@ static void __init rcu_init_geometry(void)
return;
}
+ /* Calculate the number of levels in the tree. */
+ for (i = 0; nr_cpu_ids > rcu_capacity[i]; i++) {
+ }
+ rcu_num_lvls = i;
+
/* Calculate the number of rcu_nodes at each level of the tree. */
- for (i = 1; i <= MAX_RCU_LVLS; i++)
- if (nr_cpu_ids <= rcu_capacity[i]) {
- for (j = 0; j <= i; j++) {
- int cap = rcu_capacity[i - j];
- num_rcu_lvl[j] = DIV_ROUND_UP(nr_cpu_ids, cap);
- }
- rcu_num_lvls = i;
- for (j = i + 1; j <= MAX_RCU_LVLS; j++)
- num_rcu_lvl[j] = 0;
- break;
- }
+ for (i = 0; i < rcu_num_lvls; i++) {
+ int cap = rcu_capacity[rcu_num_lvls - i];
+ num_rcu_lvl[i] = DIV_ROUND_UP(nr_cpu_ids, cap);
+ }
/* Calculate the total number of rcu_node structures. */
rcu_num_nodes = 0;
- for (i = 0; i <= MAX_RCU_LVLS; i++)
+ for (i = 0; i < rcu_num_lvls; i++)
rcu_num_nodes += num_rcu_lvl[i];
- rcu_num_nodes -= nr_cpu_ids;
}
void __init rcu_init(void)
--
1.8.3.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
