| Message ID | 1346350718-30937-8-git-send-email-paulmck@linux.vnet.ibm.com |
|---|---|
| State | Superseded |
| Headers | show |
On Thu, Aug 30, 2012 at 11:18:23AM -0700, Paul E. McKenney wrote: > From: Dimitri Sivanich <sivanich@sgi.com> > > 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> > 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 >
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. */