On x86_64 architecture with 4K page size and SLUB debugging enabled, stress
testing on p54usb has resulted in skb allocation failures of O(1) and extreme
page fragmentation. Reducing rx_mtu fixes this problem by reducing the size of
all receive skb allocations to be of O(0). This change does not impact
performance in any way.
Signed-off-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx>
---
John,
If possible, please include this in 2.6.29.
Larry
---
Index: wireless-testing/drivers/net/wireless/p54/p54common.c
===================================================================
--- wireless-testing.orig/drivers/net/wireless/p54/p54common.c
+++ wireless-testing/drivers/net/wireless/p54/p54common.c
@@ -138,6 +138,7 @@ int p54_parse_firmware(struct ieee80211_
u8 *fw_version = NULL;
size_t len;
int i;
+ int maxlen;
if (priv->rx_start)
return 0;
@@ -195,6 +196,16 @@ int p54_parse_firmware(struct ieee80211_
else
priv->rx_mtu = (size_t)
0x620 - priv->tx_hdr_len;
+ maxlen = priv->tx_hdr_len + /* USB devices */
+ sizeof(struct p54_rx_data) +
+ 4 + /* rx alignment */
+ IEEE80211_MAX_FRAG_THRESHOLD;
+ if (priv->rx_mtu > maxlen && PAGE_SIZE == 4096) {
+ printk(KERN_INFO "p54: rx_mtu reduced from %d "
+ "to %d\n", priv->rx_mtu,
+ maxlen);
+ priv->rx_mtu = maxlen;
+ }
break;
}
case BR_CODE_EXPOSED_IF:
---
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
