net-another-local-irq-disable-alloc-atomic-headache.patch

Subject: net: Another local_irq_disable/kmalloc headache
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 26 Sep 2012 16:21:08 +0200

Replace it by a local lock. Though that's pretty inefficient :(

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 net/core/skbuff.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Index: linux-stable/net/core/skbuff.c
===================================================================
--- linux-stable.orig/net/core/skbuff.c
+++ linux-stable/net/core/skbuff.c
@@ -60,6 +60,7 @@
 #include <linux/scatterlist.h>
 #include <linux/errqueue.h>
 #include <linux/prefetch.h>
+#include <linux/locallock.h>
 
 #include <net/protocol.h>
 #include <net/dst.h>
@@ -345,6 +346,7 @@ struct netdev_alloc_cache {
 	unsigned int pagecnt_bias;
 };
 static DEFINE_PER_CPU(struct netdev_alloc_cache, netdev_alloc_cache);
+static DEFINE_LOCAL_IRQ_LOCK(netdev_alloc_lock);
 
 #define NETDEV_PAGECNT_BIAS (PAGE_SIZE / SMP_CACHE_BYTES)
 
@@ -354,7 +356,7 @@ static void *__netdev_alloc_frag(unsigne
 	void *data = NULL;
 	unsigned long flags;
 
-	local_irq_save(flags);
+	local_lock_irqsave(netdev_alloc_lock, flags);
 	nc = &__get_cpu_var(netdev_alloc_cache);
 	if (unlikely(!nc->page)) {
 refill:
@@ -379,7 +381,7 @@ recycle:
 	nc->offset += fragsz;
 	nc->pagecnt_bias--;
 end:
-	local_irq_restore(flags);
+	local_unlock_irqrestore(netdev_alloc_lock, flags);
 	return data;
 }