diff options
| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2013-12-03 09:24:02 -0800 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-04-11 10:59:19 +0200 |
| commit | 1b668a69306600cb726853f0609394254f1eec12 (patch) | |
| tree | 0c585b88a5f7e60a9cc4f7bd5a0232f2e8ff7824 /kernel/rcutree.c | |
| parent | d7ab197c25758f39d4f359857db37074cc89d130 (diff) | |
rcu: Add ACCESS_ONCE() to ->n_force_qs_lh accesses
The ->n_force_qs_lh field is accessed without the benefit of any
synchronization, so this commit adds the needed ACCESS_ONCE() wrappers.
Yes, increments to ->n_force_qs_lh can be lost, but contention should
be low and the field is strictly statistical in nature, so this is not
a problem.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Diffstat (limited to 'kernel/rcutree.c')
| -rw-r--r-- | kernel/rcutree.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 9cbe263ae..d6e7d769e 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -2212,7 +2212,7 @@ static void force_quiescent_state(struct rcu_state *rsp) if (rnp_old != NULL) raw_spin_unlock(&rnp_old->fqslock); if (ret) { - rsp->n_force_qs_lh++; + ACCESS_ONCE(rsp->n_force_qs_lh)++; return; } rnp_old = rnp; @@ -2223,7 +2223,7 @@ static void force_quiescent_state(struct rcu_state *rsp) raw_spin_lock_irqsave(&rnp_old->lock, flags); raw_spin_unlock(&rnp_old->fqslock); if (ACCESS_ONCE(rsp->gp_flags) & RCU_GP_FLAG_FQS) { - rsp->n_force_qs_lh++; + ACCESS_ONCE(rsp->n_force_qs_lh)++; raw_spin_unlock_irqrestore(&rnp_old->lock, flags); return; /* Someone beat us to it. */ } |