[PATCH] iwlwifi: Suppress warnings related to GFP_ATOMIC allocations that do not matter

[Mel Gorman]

iwlwifi refills RX buffers in two ways - a direct method using GFP_ATOMIC
and a tasklet method using GFP_KERNEL. There are a number of RX buffers and
there are only serious issues when there are no RX buffers left. The driver
explicitly warns when refills are failing and the buffers are low but it
always warns when a GFP_ATOMIC allocation fails even when there is no
packet loss as a result.

This patch specifies __GFP_NOWARN for the direct refill method that uses
GFP_ATOMIC. To help identify where allocation failures might be coming
from, the stack is dumped when the RX queue is dangerously low.

Signed-off-by: Mel Gorman <mel@xxxxxxxxx>
--- 
 drivers/net/wireless/iwlwifi/iwl-rx.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/Documentation/trace/postprocess/trace-pagealloc-postprocess.pl b/Documentation/trace/postprocess/trace-pagealloc-postprocess.pl
old mode 100644
new mode 100755
diff --git a/drivers/net/wireless/iwlwifi/iwl-rx.c b/drivers/net/wireless/iwlwifi/iwl-rx.c
index 8e1bb53..f91a108 100644
--- a/drivers/net/wireless/iwlwifi/iwl-rx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-rx.c
@@ -260,10 +260,12 @@ void iwl_rx_allocate(struct iwl_priv *priv, gfp_t priority)
 			if (net_ratelimit())
 				IWL_DEBUG_INFO(priv, "Failed to allocate SKB buffer.\n");
 			if ((rxq->free_count <= RX_LOW_WATERMARK) &&
-			    net_ratelimit())
+			    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);
+				dump_stack();
+			}
 			/* We don't reschedule replenish work here -- we will
 			 * call the restock method and if it still needs
 			 * more buffers it will schedule replenish */
@@ -320,7 +322,7 @@ EXPORT_SYMBOL(iwl_rx_replenish);
 
 void iwl_rx_replenish_now(struct iwl_priv *priv)
 {
-	iwl_rx_allocate(priv, GFP_ATOMIC);
+	iwl_rx_allocate(priv, GFP_ATOMIC|__GFP_NOWARN);
 
 	iwl_rx_queue_restock(priv);
 }
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