Return-path: Received: from mail-gy0-f174.google.com ([209.85.160.174]:34754 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754390Ab1H0ASf (ORCPT ); Fri, 26 Aug 2011 20:18:35 -0400 Received: by mail-gy0-f174.google.com with SMTP id 6so3293985gya.19 for ; Fri, 26 Aug 2011 17:18:35 -0700 (PDT) From: Javier Cardona To: "John W. Linville" Cc: Javier Cardona , Thomas Pedersen , devel@lists.open80211s.org, Johannes Berg , linux-wireless@vger.kernel.org, jlopex@gmail.com Subject: [PATCH v2 3/8] mac80211: Improve mpath state locking Date: Fri, 26 Aug 2011 17:18:09 -0700 Message-Id: <1314404294-4233-4-git-send-email-javier@cozybit.com> (sfid-20110827_021838_584240_D58A2CEA) In-Reply-To: <1314404294-4233-1-git-send-email-javier@cozybit.com> References: <1314236452-7226-1-git-send-email-thomas@cozybit.com> <1314404294-4233-1-git-send-email-javier@cozybit.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: No need to take the mpath state lock when an mpath is removed. Also, no need checking the lock when reading mpath flags. Signed-off-by: Javier Cardona --- net/mac80211/mesh.h | 4 +++- net/mac80211/mesh_pathtbl.c | 14 ++++---------- 2 files changed, 7 insertions(+), 11 deletions(-) diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h index 57a2ad0..7118e8e 100644 --- a/net/mac80211/mesh.h +++ b/net/mac80211/mesh.h @@ -80,7 +80,9 @@ enum mesh_deferred_task_flags { * retry * @discovery_retries: number of discovery retries * @flags: mesh path flags, as specified on &enum mesh_path_flags - * @state_lock: mesh path state lock + * @state_lock: mesh path state lock used to protect changes to the + * mpath itself. No need to take this lock when adding or removing + * an mpath to a hash bucket on a path table. * @is_gate: the destination station of this path is a mesh gate * * diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c index 1c8c420..b895a7c 100644 --- a/net/mac80211/mesh_pathtbl.c +++ b/net/mac80211/mesh_pathtbl.c @@ -776,18 +776,17 @@ void mesh_plink_broken(struct sta_info *sta) tbl = rcu_dereference(mesh_paths); for_each_mesh_entry(tbl, p, node, i) { mpath = node->mpath; - spin_lock_bh(&mpath->state_lock); if (rcu_dereference(mpath->next_hop) == sta && mpath->flags & MESH_PATH_ACTIVE && !(mpath->flags & MESH_PATH_FIXED)) { + spin_lock_bh(&mpath->state_lock); mpath->flags &= ~MESH_PATH_ACTIVE; ++mpath->sn; spin_unlock_bh(&mpath->state_lock); mesh_path_error_tx(sdata->u.mesh.mshcfg.element_ttl, mpath->dst, cpu_to_le32(mpath->sn), reason, bcast, sdata); - } else - spin_unlock_bh(&mpath->state_lock); + } } rcu_read_unlock(); } @@ -866,7 +865,7 @@ static void mpp_path_flush(struct ieee80211_sub_if_data *sdata) if (mpath->sdata != sdata) continue; spin_lock_bh(&tbl->hashwlock[i]); - spin_lock_bh(&mpath->state_lock); + hlist_del_rcu(&node->list); call_rcu(&node->rcu, mesh_path_node_reclaim); atomic_dec(&tbl->entries); spin_unlock_bh(&tbl->hashwlock[i]); @@ -1160,15 +1159,10 @@ void mesh_path_expire(struct ieee80211_sub_if_data *sdata) if (node->mpath->sdata != sdata) continue; mpath = node->mpath; - spin_lock_bh(&mpath->state_lock); if ((!(mpath->flags & MESH_PATH_RESOLVING)) && (!(mpath->flags & MESH_PATH_FIXED)) && - time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE)) { - spin_unlock_bh(&mpath->state_lock); + time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE)) mesh_path_del(mpath->dst, mpath->sdata); - } else - spin_unlock_bh(&mpath->state_lock); - } rcu_read_unlock(); } -- 1.7.6