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authorJohannes Berg <johannes.berg@intel.com>2013-02-23 00:59:03 +0100
committerJohannes Berg <johannes.berg@intel.com>2013-03-06 16:36:00 +0100
commit8d1f7ecd2af55c0c82ffd2bff0ef0b26f16ea69f (patch)
tree51e4fe05518ea5cb51f938c4e9aa756115c7c949 /net/mac80211/cfg.c
parenta87121051ce80831a302c67286119013104f7a5a (diff)
mac80211: defer tailroom counter manipulation when roaming
During roaming, the crypto_tx_tailroom_needed_cnt counter will often take values 2,1,0,1,2 because first keys are removed and then new keys are added. This is inefficient because during the 0->1 transition, synchronize_net must be called to avoid packet races, although typically no packets would be flowing during that time. To avoid that, defer the decrement (2->1, 1->0) when keys are removed (by half a second). This means the counter will really have the values 2,2,2,3,4 ... 2, thus never reaching 0 and having to do the 0->1 transition. Note that this patch entirely disregards the drivers for which this optimisation was done to start with, for them the key removal itself will be expensive because it has to synchronize_net() after the counter is incremented to remove the key from HW crypto. For them the sequence will look like this: 0,1,0,1,0,1,0,1,0 (*) which is clearly a lot more inefficient. This could be addressed separately, during key removal the 0->1->0 sequence isn't necessary. (*) it starts at 0 because HW crypto is on, then goes to 1 when HW crypto is disabled for a key, then back to 0 because the key is deleted; this happens for both keys in the example. When new keys are added, it goes to 1 first because they're added in software; when a key is moved to hardware it goes back to 0 Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/mac80211/cfg.c')
-rw-r--r--net/mac80211/cfg.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index f9cbdc29946..8baa561c8f5 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -254,7 +254,7 @@ static int ieee80211_del_key(struct wiphy *wiphy, struct net_device *dev,
goto out_unlock;
}
- __ieee80211_key_free(key);
+ __ieee80211_key_free(key, true);
ret = 0;
out_unlock: