iwlwifi: use GFP_KERNEL to allocate Rx SKB memory
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>
diff --git a/drivers/net/wireless/iwlwifi/iwl-rx.c b/drivers/net/wireless/iwlwifi/iwl-rx.c
index 919a775..c5f1aa0 100644
--- a/drivers/net/wireless/iwlwifi/iwl-rx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-rx.c
@@ -244,25 +244,31 @@
struct list_head *element;
struct iwl_rx_mem_buffer *rxb;
unsigned long flags;
- spin_lock_irqsave(&rxq->lock, flags);
- while (!list_empty(&rxq->rx_used)) {
+
+ while (1) {
+ spin_lock_irqsave(&rxq->lock, flags);
+
+ if (list_empty(&rxq->rx_used)) {
+ spin_unlock_irqrestore(&rxq->lock, flags);
+ return;
+ }
element = rxq->rx_used.next;
rxb = list_entry(element, struct iwl_rx_mem_buffer, list);
+ list_del(element);
+
+ spin_unlock_irqrestore(&rxq->lock, flags);
/* Alloc a new receive buffer */
rxb->skb = alloc_skb(priv->hw_params.rx_buf_size + 256,
- __GFP_NOWARN | GFP_ATOMIC);
+ GFP_KERNEL);
if (!rxb->skb) {
- if (net_ratelimit())
- printk(KERN_CRIT DRV_NAME
- ": Can not allocate SKB buffers\n");
+ printk(KERN_CRIT DRV_NAME
+ "Can not allocate SKB buffers\n");
/* We don't reschedule replenish work here -- we will
* call the restock method and if it still needs
* more buffers it will schedule replenish */
break;
}
- priv->alloc_rxb_skb++;
- list_del(element);
/* Get physical address of RB/SKB */
rxb->real_dma_addr = pci_map_single(
@@ -276,12 +282,15 @@
rxb->aligned_dma_addr = ALIGN(rxb->real_dma_addr, 256);
skb_reserve(rxb->skb, rxb->aligned_dma_addr - rxb->real_dma_addr);
+ spin_lock_irqsave(&rxq->lock, flags);
+
list_add_tail(&rxb->list, &rxq->rx_free);
rxq->free_count++;
+ priv->alloc_rxb_skb++;
+
+ spin_unlock_irqrestore(&rxq->lock, flags);
}
- spin_unlock_irqrestore(&rxq->lock, flags);
}
-EXPORT_SYMBOL(iwl_rx_allocate);
void iwl_rx_replenish(struct iwl_priv *priv)
{