From patchwork Mon Aug 29 20:23:05 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Javier Cardona X-Patchwork-Id: 1110482 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.4) with ESMTP id p7TKNLaj026114 for ; Mon, 29 Aug 2011 20:23:32 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755069Ab1H2UXY (ORCPT ); Mon, 29 Aug 2011 16:23:24 -0400 Received: from mail-pz0-f42.google.com ([209.85.210.42]:54157 "EHLO mail-pz0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755028Ab1H2UXW (ORCPT ); Mon, 29 Aug 2011 16:23:22 -0400 Received: by mail-pz0-f42.google.com with SMTP id 37so9020873pzk.1 for ; Mon, 29 Aug 2011 13:23:22 -0700 (PDT) Received: by 10.142.125.14 with SMTP id x14mr2594965wfc.226.1314649402203; Mon, 29 Aug 2011 13:23:22 -0700 (PDT) Received: from localhost.localdomain (99-8-184-170.lightspeed.snfcca.sbcglobal.net [99.8.184.170]) by mx.google.com with ESMTPS id g14sm5303323wfh.22.2011.08.29.13.23.21 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 29 Aug 2011 13:23:21 -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 v3 3/7] mac80211: Improve mpath state locking Date: Mon, 29 Aug 2011 13:23:05 -0700 Message-Id: <1314649389-7115-4-git-send-email-javier@cozybit.com> X-Mailer: git-send-email 1.7.6 In-Reply-To: <1314649389-7115-1-git-send-email-javier@cozybit.com> References: <1314649389-7115-1-git-send-email-javier@cozybit.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Mon, 29 Aug 2011 20:23:33 +0000 (UTC) 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(); }