On 01/07/2011 02:26 PM, Eric Dumazet wrote:
Le vendredi 07 janvier 2011 Ã 14:20 -0800, Ben Greear a Ãcrit :
On 0
Using skb_copy() is wrong then, since it makes a copy (order-1
allocations)
It should use :
skb_alloc( actual_size_of_frame not the 3840 thing ...)
copy(data)
We need the extra stuff copied too I think (like skb->cb).
If you could provide a bit more complete example code, I'll be happy
to test it...
take a random drivers/net using copybreak ... say ... tg3.c
lines 4785
len = length_of_the_current_frame
copy_skb = netdev_alloc_skb(..., len);
// allocates exact required size not a byte more....
...
skb_copy_from_linear_data(skb, copy_skb->data, len);
...
skb_put(skb, len);
...
That seems fine for drivers, but I'm guessing something different
would be needed in the mac80211/rx.c code:
I figure doing the fix here might be a nice quick fix,
and would help with all funky drivers. Later, can fix the
ath9k to do the skb copying as soon as DMA is done?
/*
* This function returns whether or not the SKB
* was destined for RX processing or not, which,
* if consume is true, is equivalent to whether
* or not the skb was consumed.
*/
static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
struct sk_buff *skb, bool consume)
{
struct ieee80211_local *local = rx->local;
struct ieee80211_sub_if_data *sdata = rx->sdata;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
struct ieee80211_hdr *hdr = (void *)skb->data;
int prepares;
rx->skb = skb;
status->rx_flags |= IEEE80211_RX_RA_MATCH;
prepares = prepare_for_handlers(rx, hdr);
if (!prepares)
return false;
if (status->flag & RX_FLAG_MMIC_ERROR) {
if (status->rx_flags & IEEE80211_RX_RA_MATCH)
ieee80211_rx_michael_mic_report(hdr, rx);
return false;
}
if (!consume) {
skb = skb_copy(skb, GFP_ATOMIC);
if (!skb) {
if (net_ratelimit()) {
printk("failed skb_copy, skb->len: %i\n", skb->len);
wiphy_debug(local->hw.wiphy,
"failed to copy skb for %s\n",
sdata->name);
}
return true;
}
rx->skb = skb;
}
ieee80211_invoke_rx_handlers(rx);
return true;
}
Thanks,
Ben
--
Ben Greear <greearb@xxxxxxxxxxxxxxx>
Candela Technologies Inc http://www.candelatech.com
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