On Wed, 2013-04-03 at 09:48 -0700, greearb@xxxxxxxxxxxxxxx wrote:
> From: Ben Greear <greearb@xxxxxxxxxxxxxxx>
>
> When one has multiple station VIFS all connected to the same
> AP, the rx logic becomes a linear walk of all stations. To
> improve performance in this case, hash the station VIFs on
> the VIF MAC. This significantly improves performance: 70Mbps
> without the patch, 190Mbps with patch, when using 50 stations
> receiving TCP traffic.
>
> Probably not many people doing this, so not worth pushing upstream
> at this time.
I tend to agree.
> +++ b/net/mac80211/sta_info.c
> @@ -77,19 +77,42 @@ static int sta_info_hash_del(struct ieee80211_local *local,
> s = rcu_dereference_protected(local->sta_hash[STA_HASH(sta->sta.addr)],
> lockdep_is_held(&local->sta_mtx));
> if (!s)
> - return -ENOENT;
> + goto try_lhash;
Does this make sense? If the station doesn't exist in the regular hash,
it really shouldn't be in the vif hash either, no?
> if (rcu_access_pointer(s->hnext)) {
> rcu_assign_pointer(s->hnext, sta->hnext);
> + goto try_lhash;
> + }
> +
> + /* Remove from the local VIF addr hash */
> +try_lhash:
That last goto there seems a bit pointless :)
> + s = rcu_dereference_protected(local->sta_vhash[STA_HASH(sta->sdata->vif.addr)],
> + lockdep_is_held(&local->sta_mtx));
> + if (!s)
> + return -ENONET;
You probably want -ENOENT, not -ENONET.
> +struct sta_info *sta_info_get_by_vif(struct ieee80211_local *local,
> + const u8 *vif_addr, const u8 * sta_addr) {
> + struct sta_info *sta;
> +
> + sta = rcu_dereference_check(local->sta_vhash[STA_HASH(vif_addr)],
> + lockdep_is_held(&local->sta_mtx));
> + while (sta) {
> + if (ether_addr_equal(sta->sdata->vif.addr, vif_addr) &&
> + ether_addr_equal(sta->sta.addr, sta_addr))
> + break;
> + sta = rcu_dereference_check(sta->vnext,
> + lockdep_is_held(&local->sta_mtx));
Almost all of your rcu_dereference_check() invocations should be
rcu_dereference_protected(). See include/linux/rcupdate.h :)
johannes
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