Previously we allocate Rx SKB with GFP_ATOMIC flag. This is because we need
to hold a spinlock to protect the two rx_used and rx_free lists operation
in the rxq.
spin_lock();
...
element = rxq->rx_used.next;
element->skb = alloc_skb(..., GFP_ATOMIC);
list_del(element);
list_add_tail(&element->list, &rxq->rx_free);
...
spin_unlock();
After spliting the rx_used delete and rx_free insert into two operations,
we don't require the skb allocation in an atomic context any more (the
function itself is scheduled in a workqueue).
spin_lock();
...
element = rxq->rx_used.next;
list_del(element);
...
spin_unlock();
...
element->skb = alloc_skb(..., GFP_KERNEL);
...
spin_lock()
...
list_add_tail(&element->list, &rxq->rx_free);
...
spin_unlock();
This patch should fix the "iwlagn: Can not allocate SKB buffers" warning
we see recently.
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Acked-by: Tomas Winkler <tomas.winkler@intel.com>
Cc: stable@kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>
f1bc4ac61f