iwlwifi: reduce noise when skb allocation fails

commit f82a924cc88a5541df1d4b9d38a0968cd077a051 upstream.

Replenishment of receive buffers is done in the tasklet handling
received frames as well as in a workqueue. When we are in the tasklet
we cannot sleep and thus attempt atomic skb allocations. It is generally
not a big problem if this fails since iwl_rx_allocate is always followed
by a call to iwl_rx_queue_restock which will queue the work to replenish
the buffers at a time when sleeping is allowed.

We thus add the __GFP_NOWARN to the skb allocation in iwl_rx_allocate to
reduce the noise if such an allocation fails while we still have enough
buffers. We do maintain the warning and the error message when we are low
on buffers to communicate to the user that there is a potential problem with
memory availability on system

This addresses issue reported upstream in thread "iwlagn: order 2 page
allocation failures" in
http://thread.gmane.org/gmane.linux.kernel.wireless.general/39187

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/net/wireless/iwlwifi/iwl-rx.c b/drivers/net/wireless/iwlwifi/iwl-rx.c
index f718ebea30dba3c20b9101f2e4ce4af24c868fc4..a13f678fe44cca53aed9507be18d3d3813a30347 100644 (file)
--- a/drivers/net/wireless/iwlwifi/iwl-rx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-rx.c
@@ -250,12 +250,20 @@ void iwl_rx_allocate(struct iwl_priv *priv, gfp_t priority)
                }
                spin_unlock_irqrestore(&rxq->lock, flags);
 
+               if (rxq->free_count > RX_LOW_WATERMARK)
+                       priority |= __GFP_NOWARN;
                /* Alloc a new receive buffer */
                skb = alloc_skb(priv->hw_params.rx_buf_size + 256,
                                                priority);
 
                if (!skb) {
-                       IWL_CRIT(priv, "Can not allocate SKB buffers\n");
+                       if (net_ratelimit())
+                               IWL_DEBUG_INFO(priv, "Failed to allocate SKB buffer.\n");
+                       if ((rxq->free_count <= RX_LOW_WATERMARK) &&
+                           net_ratelimit())
+                               IWL_CRIT(priv, "Failed to allocate SKB buffer with %s. Only %u free buffers remaining.\n",
+                                        priority == GFP_ATOMIC ?  "GFP_ATOMIC" : "GFP_KERNEL",
+                                        rxq->free_count);
                        /* We don't reschedule replenish work here -- we will
                         * call the restock method and if it still needs
                         * more buffers it will schedule replenish */

diff --git a/drivers/net/wireless/iwlwifi/iwl3945-base.c b/drivers/net/wireless/iwlwifi/iwl3945-base.c
index 56a2be9c0d2c624ad0167db28480cf4302990795..4fac58260001f9ed715b619ad986c6bc50a03f5a 100644 (file)
--- a/drivers/net/wireless/iwlwifi/iwl3945-base.c
+++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c
@@ -1208,11 +1208,18 @@ static void iwl3945_rx_allocate(struct iwl_priv *priv, gfp_t priority)
                }
                spin_unlock_irqrestore(&rxq->lock, flags);
 
+               if (rxq->free_count > RX_LOW_WATERMARK)
+                       priority |= __GFP_NOWARN;
                /* Alloc a new receive buffer */
                skb = alloc_skb(priv->hw_params.rx_buf_size, priority);
                if (!skb) {
                        if (net_ratelimit())
-                               IWL_CRIT(priv, ": Can not allocate SKB buffers\n");
+                               IWL_DEBUG_INFO(priv, "Failed to allocate SKB buffer.\n");
+                       if ((rxq->free_count <= RX_LOW_WATERMARK) &&
+                           net_ratelimit())
+                               IWL_CRIT(priv, "Failed to allocate SKB buffer with %s. Only %u free buffers remaining.\n",
+                                        priority == GFP_ATOMIC ?  "GFP_ATOMIC" : "GFP_KERNEL",
+                                        rxq->free_count);
                        /* We don't reschedule replenish work here -- we will
                         * call the restock method and if it still needs
                         * more buffers it will schedule replenish */