diff options
| author | Alexander Gordeev <agordeev@redhat.com> | 2015-06-03 09:18:26 +0300 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-07-16 00:45:15 +0300 |
| commit | 9618138b09260e3df5af5a0d7bdc8fca010f6a3f (patch) | |
| tree | 9f647d7621e5bf1ddb21d0c650afe9c2b35f0861 /kernel/rcu | |
| parent | 679f9858b1769d740d933f5f1ad9dbe3292f26d2 (diff) | |
| download | linux-9618138b09260e3df5af5a0d7bdc8fca010f6a3f.tar.xz | |
rcu: Simplify rcu_init_geometry() capacity arithmetics
Current code suggests that introducing the extra level to
rcu_capacity[] array makes some of the arithmetic easier.
Well, in fact it appears rather confusing and unnecessary.
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.c | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 37ca8a867a1c..2103beedb49f 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -4082,7 +4082,7 @@ static void __init rcu_init_geometry(void) { ulong d; int i; - int rcu_capacity[MAX_RCU_LVLS + 1]; + int rcu_capacity[MAX_RCU_LVLS]; /* * Initialize any unspecified boot parameters. @@ -4119,29 +4119,27 @@ static void __init rcu_init_geometry(void) /* * Compute number of nodes that can be handled an rcu_node tree - * with the given number of levels. Setting rcu_capacity[0] makes - * some of the arithmetic easier. + * with the given number of levels. */ - rcu_capacity[0] = 1; - rcu_capacity[1] = rcu_fanout_leaf; - for (i = 2; i <= MAX_RCU_LVLS; i++) + rcu_capacity[0] = rcu_fanout_leaf; + for (i = 1; i < MAX_RCU_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]) + if (nr_cpu_ids > rcu_capacity[MAX_RCU_LVLS - 1]) panic("rcu_init_geometry: rcu_capacity[] is too small"); /* Calculate the number of levels in the tree. */ - for (i = 1; nr_cpu_ids > rcu_capacity[i]; i++) { + for (i = 0; nr_cpu_ids > rcu_capacity[i]; i++) { } - rcu_num_lvls = i; + rcu_num_lvls = i + 1; /* Calculate the number of rcu_nodes at each level of the tree. */ for (i = 0; i < rcu_num_lvls; i++) { - int cap = rcu_capacity[rcu_num_lvls - i]; + int cap = rcu_capacity[(rcu_num_lvls - 1) - i]; num_rcu_lvl[i] = DIV_ROUND_UP(nr_cpu_ids, cap); } |