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| author | Dimitri Sivanich <sivanich@sgi.com> | 2012-06-29 14:17:29 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-09-23 07:41:53 -0700 |
| commit | b402b73b3afe3614bc0e921ebe18013ea103115a (patch) | |
| tree | d5f941ae2bbae05e496ff1b8415bffc30b6a80b8 /kernel | |
| parent | b626c1b689364859ccd2e86d5e043aeadfeb2cd4 (diff) | |
| download | linux-b402b73b3afe3614bc0e921ebe18013ea103115a.tar.gz linux-b402b73b3afe3614bc0e921ebe18013ea103115a.tar.bz2 linux-b402b73b3afe3614bc0e921ebe18013ea103115a.zip | |
rcu: Segregate rcu_state fields to improve cache locality
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 <sivanich@sgi.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Dimitri Sivanich <sivanich@sgi.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcutree.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/rcutree.h b/kernel/rcutree.h index effb2733b7fc..5d92b80a0a28 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. */ |