| Message ID | 20130418220443.GB3759@localhost (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Thu, Apr 18, 2013 at 06:04:43PM -0400, Bob Copeland wrote: > The RCU docs used to state that rcu_barrier() included a wait > for an RCU grace period; however the comments for rcu_barrier() > as of commit f0a0e6f... "rcu: Clarify memory-ordering properties > of grace-period primitives" contradict this. > > So add back synchronize_{rcu,net}() to where they once were, > but keep the rcu_barrier()s for the call_rcu() callbacks. > > Cc: stable <stable@vger.kernel.org> > Signed-off-by: Bob Copeland <bob@cozybit.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > --- > net/mac80211/iface.c | 5 +++-- > net/mac80211/pm.c | 1 + > 2 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c > index b6abaaa..c634aff 100644 > --- a/net/mac80211/iface.c > +++ b/net/mac80211/iface.c > @@ -836,11 +836,12 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, > * > * sta_info_flush_cleanup() requires rcu_barrier() > * first to wait for the station call_rcu() calls > - * to complete, here we need at least sychronize_rcu() > - * it to wait for the RX path in case it is using the > + * to complete, and we also need synchronize_rcu() > + * to wait for the RX path in case it is using the > * interface and enqueuing frames at this very time on > * another CPU. > */ > + synchronize_rcu(); > rcu_barrier(); > sta_info_flush_cleanup(sdata); > > diff --git a/net/mac80211/pm.c b/net/mac80211/pm.c > index 4431f0f..7fc5d0d 100644 > --- a/net/mac80211/pm.c > +++ b/net/mac80211/pm.c > @@ -38,6 +38,7 @@ int __ieee80211_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan) > IEEE80211_QUEUE_STOP_REASON_SUSPEND); > > /* flush out all packets and station cleanup call_rcu()s */ > + synchronize_net(); > rcu_barrier(); > > ieee80211_flush_queues(local, NULL); > -- > 1.7.10.4 > > -- > Bob Copeland %% www.bobcopeland.com > -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index b6abaaa..c634aff 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -836,11 +836,12 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, * * sta_info_flush_cleanup() requires rcu_barrier() * first to wait for the station call_rcu() calls - * to complete, here we need at least sychronize_rcu() - * it to wait for the RX path in case it is using the + * to complete, and we also need synchronize_rcu() + * to wait for the RX path in case it is using the * interface and enqueuing frames at this very time on * another CPU. */ + synchronize_rcu(); rcu_barrier(); sta_info_flush_cleanup(sdata); diff --git a/net/mac80211/pm.c b/net/mac80211/pm.c index 4431f0f..7fc5d0d 100644 --- a/net/mac80211/pm.c +++ b/net/mac80211/pm.c @@ -38,6 +38,7 @@ int __ieee80211_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan) IEEE80211_QUEUE_STOP_REASON_SUSPEND); /* flush out all packets and station cleanup call_rcu()s */ + synchronize_net(); rcu_barrier(); ieee80211_flush_queues(local, NULL);
The RCU docs used to state that rcu_barrier() included a wait for an RCU grace period; however the comments for rcu_barrier() as of commit f0a0e6f... "rcu: Clarify memory-ordering properties of grace-period primitives" contradict this. So add back synchronize_{rcu,net}() to where they once were, but keep the rcu_barrier()s for the call_rcu() callbacks. Cc: stable <stable@vger.kernel.org> Signed-off-by: Bob Copeland <bob@cozybit.com> --- net/mac80211/iface.c | 5 +++-- net/mac80211/pm.c | 1 + 2 files changed, 4 insertions(+), 2 deletions(-)