From: Dimitri Sivanich <[email protected]> The fields in the rcu_state structure that are protected by the root rcu_node structure's ->lock can share a cache line with the fields protected by ->onofflock. This can result in excessive memory contention on large systems, so this commit applies ____cacheline_internodealigned_in_smp to the ->onofflock field in order to segregate them.
Signed-off-by: Dimitri Sivanich <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> Tested-by: Dimitri Sivanich <[email protected]> Reviewed-by: Josh Triplett <[email protected]> --- kernel/rcutree.h | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/kernel/rcutree.h b/kernel/rcutree.h index effb273..5d92b80 100644 --- a/kernel/rcutree.h +++ b/kernel/rcutree.h @@ -394,7 +394,8 @@ struct rcu_state { /* End of fields guarded by root rcu_node's lock. */ - raw_spinlock_t onofflock; /* exclude on/offline and */ + raw_spinlock_t onofflock ____cacheline_internodealigned_in_smp; + /* exclude on/offline and */ /* starting new GP. */ struct rcu_head *orphan_nxtlist; /* Orphaned callbacks that */ /* need a grace period. */ -- 1.7.8 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
