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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2014-09-04 12:21:41 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2014-11-03 19:20:03 -0800 |
| commit | 11bbb235c26f93b7c69e441452e44adbf6ed6996 (patch) | |
| tree | fbb0889e0a86daf78272f16487a7682fe9cc0117 | |
| parent | 28ced795cbb43f01146feb96d03a72facdee9911 (diff) | |
| download | blackbird-op-linux-11bbb235c26f93b7c69e441452e44adbf6ed6996.tar.gz blackbird-op-linux-11bbb235c26f93b7c69e441452e44adbf6ed6996.zip | |
rcu: Use DEFINE_PER_CPU_SHARED_ALIGNED for rcu_data
The rcu_data per-CPU variable has a number of fields that are atomically
manipulated, potentially by any CPU. This situation can result in false
sharing with per-CPU variables that have the misfortune of being allocated
adjacent to rcu_data in memory. This commit therefore changes the
DEFINE_PER_CPU() to DEFINE_PER_CPU_SHARED_ALIGNED() in order to avoid
this false sharing.
Reported-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
| -rw-r--r-- | kernel/rcu/tree.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index c0673c56fb1a..ab6fcfb4fe11 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -105,7 +105,7 @@ struct rcu_state sname##_state = { \ .name = RCU_STATE_NAME(sname), \ .abbr = sabbr, \ }; \ -DEFINE_PER_CPU(struct rcu_data, sname##_data) +DEFINE_PER_CPU_SHARED_ALIGNED(struct rcu_data, sname##_data) RCU_STATE_INITIALIZER(rcu_sched, 's', call_rcu_sched); RCU_STATE_INITIALIZER(rcu_bh, 'b', call_rcu_bh); |
