Return-path: Received: from bar.sig21.net ([80.81.252.164]:50589 "EHLO bar.sig21.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752107Ab0K2Pve (ORCPT ); Mon, 29 Nov 2010 10:51:34 -0500 Date: Mon, 29 Nov 2010 16:51:26 +0100 From: Johannes Stezenbach To: Johannes Berg Cc: linux-wireless@vger.kernel.org, Ivo van Doorn , Gertjan van Wingerde , "John W. Linville" Subject: [PATCH v2 RFC] mac80211: fix "NOHZ: local_softirq_pending 08" Message-ID: <20101129155126.GA32482@sig21.net> References: <20101129145439.GA31910@sig21.net> <1291043349.3532.4.camel@jlt3.sipsolutions.net> <20101129152735.GA32319@sig21.net> <1291045056.3532.5.camel@jlt3.sipsolutions.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1291045056.3532.5.camel@jlt3.sipsolutions.net> Sender: linux-wireless-owner@vger.kernel.org List-ID: ieee80211_tx_status() documentation says "This function may not be called in IRQ context", and it is called by rt2800usb from a workqueue context. However, ieee80211_tx_status() is meant to be called from tasklets and thus uses netif_rx(). Add a new ieee80211_tx_status_ni() which does the same thing but uses netif_rx_ni() instead of netif_rx(). This change fixes the "NOHZ: local_softirq_pending 08" messages I've been getting with rt2800usb. Signed-off-by: Johannes Stezenbach --- v2: add ieee80211_tx_status_ni() Note: the patch is now incomplete, rt2x00lib_txdone() is used by several drivers and I'm currently checking if ieee80211_tx_status_ni() can be used by all of them of if I need to split rt2x00lib_txdone() in two versions. An updated patch with the rt2x00 changes will follow, but I'm seeking feedback if the base change here is OK. include/net/mac80211.h | 23 +++++++++++++++++++---- net/mac80211/status.c | 19 ++++++++++++++++--- 2 files changed, 35 insertions(+), 7 deletions(-) diff --git a/include/net/mac80211.h b/include/net/mac80211.h index eaa4aff..df42312 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -2055,8 +2055,8 @@ static inline void ieee80211_rx_ni(struct ieee80211_hw *hw, * * This function may not be called in IRQ context. Calls to this function * for a single hardware must be synchronized against each other. Calls - * to this function and ieee80211_tx_status_irqsafe() may not be mixed - * for a single hardware. + * to this function, ieee80211_tx_status_ni() and ieee80211_tx_status_irqsafe() + * may not be mixed for a single hardware. * * @hw: the hardware the frame was transmitted by * @skb: the frame that was transmitted, owned by mac80211 after this call @@ -2065,13 +2065,28 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb); /** + * ieee80211_tx_status_ni - transmit status callback (in process context) + * + * Like ieee80211_tx_status() but can be called in process context. + * + * Calls to this function, ieee80211_tx_status() and + * ieee80211_tx_status_irqsafe() may not be mixed + * for a single hardware. + * + * @hw: the hardware the frame was transmitted by + * @skb: the frame that was transmitted, owned by mac80211 after this call + */ +void ieee80211_tx_status_ni(struct ieee80211_hw *hw, + struct sk_buff *skb); + +/** * ieee80211_tx_status_irqsafe - IRQ-safe transmit status callback * * Like ieee80211_tx_status() but can be called in IRQ context * (internally defers to a tasklet.) * - * Calls to this function and ieee80211_tx_status() may not be mixed for a - * single hardware. + * Calls to this function, ieee80211_tx_status() and + * ieee80211_tx_status_ni() may not be mixed for a single hardware. * * @hw: the hardware the frame was transmitted by * @skb: the frame that was transmitted, owned by mac80211 after this call diff --git a/net/mac80211/status.c b/net/mac80211/status.c index bed7e32..ce4d239 100644 --- a/net/mac80211/status.c +++ b/net/mac80211/status.c @@ -170,7 +170,8 @@ static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb) */ #define STA_LOST_PKT_THRESHOLD 50 -void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb) +void __ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb, + int (*netif_rx_func)(struct sk_buff *skb)) { struct sk_buff *skb2; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; @@ -403,7 +404,7 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb) skb2 = skb_clone(skb, GFP_ATOMIC); if (skb2) { skb2->dev = prev_dev; - netif_rx(skb2); + netif_rx_func(skb2); } } @@ -412,10 +413,22 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb) } if (prev_dev) { skb->dev = prev_dev; - netif_rx(skb); + netif_rx_func(skb); skb = NULL; } rcu_read_unlock(); dev_kfree_skb(skb); } + +void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb) +{ + __ieee80211_tx_status(hw, skb, netif_rx); +} EXPORT_SYMBOL(ieee80211_tx_status); + +void ieee80211_tx_status_ni(struct ieee80211_hw *hw, + struct sk_buff *skb) +{ + __ieee80211_tx_status(hw, skb, netif_rx_ni); +} +EXPORT_SYMBOL(ieee80211_tx_status_ni);