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p54usb: Fix to prevent SKB memory allocation errors with 4K page size

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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@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Larry Finger 2009-01-03 12:45:12 -06:00 committed by John W. Linville
parent d1b29405bd
commit 51fb80fefe
1 changed files with 11 additions and 0 deletions
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11
drivers/net/wireless/p54/p54common.c
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@ -138,6 +138,7 @@ int p54_parse_firmware(struct ieee80211_hw *dev, const struct firmware *fw)
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_hw *dev, const struct firmware *fw)
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: