From: Amerigo Wang Date: Fri, 24 Aug 2012 21:41:11 +0000 (+0000) Subject: netpoll: revert 6bdb7fe3104 and fix be_poll() instead X-Git-Tag: Ubuntu-5.0.0-8.9~15363^2~18 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=072a9c48600409d72aeb0d5b29fbb75861a06631;p=mirror_ubuntu-disco-kernel.git netpoll: revert 6bdb7fe3104 and fix be_poll() instead Against -net. In the patch "netpoll: re-enable irq in poll_napi()", I tried to fix the following warning: [100718.051041] ------------[ cut here ]------------ [100718.051048] WARNING: at kernel/softirq.c:159 local_bh_enable_ip+0x7d/0xb0() (Not tainted) [100718.051049] Hardware name: ProLiant BL460c G7 ... [100718.051068] Call Trace: [100718.051073] [] ? warn_slowpath_common+0x87/0xc0 [100718.051075] [] ? warn_slowpath_null+0x1a/0x20 [100718.051077] [] ? local_bh_enable_ip+0x7d/0xb0 [100718.051080] [] ? _spin_unlock_bh+0x1b/0x20 [100718.051085] [] ? be_process_mcc+0x74/0x230 [be2net] [100718.051088] [] ? be_poll_tx_mcc+0x16c/0x290 [be2net] [100718.051090] [] ? netpoll_poll_dev+0xd6/0x490 [100718.051095] [] ? bond_poll_controller+0x75/0x80 [bonding] [100718.051097] [] ? netpoll_poll_dev+0x45/0x490 [100718.051100] [] ? ksize+0x19/0x80 [100718.051102] [] ? netpoll_send_skb_on_dev+0x157/0x240 by reenabling IRQ before calling ->poll, but it seems more problems are introduced after that patch: http://ozlabs.org/~akpm/stuff/IMG_20120824_122054.jpg http://marc.info/?l=linux-netdev&m=134563282530588&w=2 So it is safe to fix be2net driver code directly. This patch reverts the offending commit and fixes be_poll() by avoid disabling BH there, this is okay because be_poll() can be called either by poll_napi() which already disables IRQ, or by net_rx_action() which already disables BH. Reported-by: Andrew Morton Reported-by: Sylvain Munaut Cc: Sylvain Munaut Cc: Andrew Morton Cc: David Miller Cc: Sathya Perla Cc: Subbu Seetharaman Cc: Ajit Khaparde Signed-off-by: Cong Wang Tested-by: Sylvain Munaut Signed-off-by: David S. Miller --- diff --git a/drivers/net/ethernet/emulex/benet/be_cmds.c b/drivers/net/ethernet/emulex/benet/be_cmds.c index 7fac97b4bb59..8c63d06ab12b 100644 --- a/drivers/net/ethernet/emulex/benet/be_cmds.c +++ b/drivers/net/ethernet/emulex/benet/be_cmds.c @@ -259,7 +259,7 @@ int be_process_mcc(struct be_adapter *adapter) int num = 0, status = 0; struct be_mcc_obj *mcc_obj = &adapter->mcc_obj; - spin_lock_bh(&adapter->mcc_cq_lock); + spin_lock(&adapter->mcc_cq_lock); while ((compl = be_mcc_compl_get(adapter))) { if (compl->flags & CQE_FLAGS_ASYNC_MASK) { /* Interpret flags as an async trailer */ @@ -280,7 +280,7 @@ int be_process_mcc(struct be_adapter *adapter) if (num) be_cq_notify(adapter, mcc_obj->cq.id, mcc_obj->rearm_cq, num); - spin_unlock_bh(&adapter->mcc_cq_lock); + spin_unlock(&adapter->mcc_cq_lock); return status; } @@ -295,7 +295,9 @@ static int be_mcc_wait_compl(struct be_adapter *adapter) if (be_error(adapter)) return -EIO; + local_bh_disable(); status = be_process_mcc(adapter); + local_bh_enable(); if (atomic_read(&mcc_obj->q.used) == 0) break; diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c index 90a903d83d87..78b8aa8069f0 100644 --- a/drivers/net/ethernet/emulex/benet/be_main.c +++ b/drivers/net/ethernet/emulex/benet/be_main.c @@ -3763,7 +3763,9 @@ static void be_worker(struct work_struct *work) /* when interrupts are not yet enabled, just reap any pending * mcc completions */ if (!netif_running(adapter->netdev)) { + local_bh_disable(); be_process_mcc(adapter); + local_bh_enable(); goto reschedule; } diff --git a/net/core/netpoll.c b/net/core/netpoll.c index 346b1eb83a1f..e4ba3e70c174 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -168,24 +168,16 @@ static void poll_napi(struct net_device *dev) struct napi_struct *napi; int budget = 16; - WARN_ON_ONCE(!irqs_disabled()); - list_for_each_entry(napi, &dev->napi_list, dev_list) { - local_irq_enable(); if (napi->poll_owner != smp_processor_id() && spin_trylock(&napi->poll_lock)) { - rcu_read_lock_bh(); budget = poll_one_napi(rcu_dereference_bh(dev->npinfo), napi, budget); - rcu_read_unlock_bh(); spin_unlock(&napi->poll_lock); - if (!budget) { - local_irq_disable(); + if (!budget) break; - } } - local_irq_disable(); } }