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| author | Lai Jiangshan <laijs@cn.fujitsu.com> | 2012-03-06 10:57:34 +0100 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-04-30 19:48:24 +0200 |
| commit | dc87917501e324701dbfb249def44054b5220187 (patch) | |
| tree | e39ebf104875f11b8f6fd56e98366918bacc4dca /kernel/srcu.c | |
| parent | rcu: Remove unused srcu_barrier() (diff) | |
| download | linux-dc87917501e324701dbfb249def44054b5220187.tar.xz linux-dc87917501e324701dbfb249def44054b5220187.zip | |
rcu: Improve srcu_readers_active_idx()'s cache locality
Expand the calls to srcu_readers_active_idx() from srcu_readers_active()
inline. This change improves cache locality by interating over the CPUs
once rather than twice.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/srcu.c')
| -rw-r--r-- | kernel/srcu.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/kernel/srcu.c b/kernel/srcu.c index e0139a274856..a43211c92863 100644 --- a/kernel/srcu.c +++ b/kernel/srcu.c @@ -193,7 +193,14 @@ static bool srcu_readers_active_idx_check(struct srcu_struct *sp, int idx) */ static int srcu_readers_active(struct srcu_struct *sp) { - return srcu_readers_active_idx(sp, 0) + srcu_readers_active_idx(sp, 1); + int cpu; + unsigned long sum = 0; + + for_each_possible_cpu(cpu) { + sum += ACCESS_ONCE(per_cpu_ptr(sp->per_cpu_ref, cpu)->c[0]); + sum += ACCESS_ONCE(per_cpu_ptr(sp->per_cpu_ref, cpu)->c[1]); + } + return sum; } /** |