| Message ID | 20130418222649.GC3759@localhost (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Thu, 2013-04-18 at 18:26 -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. Applied, thanks for spotting this! johannes -- 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/cfg.c b/net/mac80211/cfg.c index 72ab1c0..dcffca4 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -1043,6 +1043,7 @@ static int ieee80211_stop_ap(struct wiphy *wiphy, struct net_device *dev) list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) sta_info_flush_defer(vlan); sta_info_flush_defer(sdata); + synchronize_net(); rcu_barrier(); list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) { sta_info_flush_cleanup(vlan); 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> --- v2: also in cfg.c net/mac80211/cfg.c | 1 + net/mac80211/iface.c | 5 +++-- net/mac80211/pm.c | 1 + 3 files changed, 5 insertions(+), 2 deletions(-)