Re: problems with e1000 and jumboframes

From: Evgeniy Polyakov
Date: Thu Aug 03 2006 - 11:39:28 EST


On Thu, Aug 03, 2006 at 07:16:31PM +0400, Evgeniy Polyakov (johnpol@xxxxxxxxxxx) wrote:
> > >then skb_alloc adds a little
> > >(sizeof(struct skb_shared_info)) at the end, and this ends up
> > >in 32k request just for 9k jumbo frame.
> >
> > Strange, why this skb_shared_info cannon be added before first alignment?
> > And what about smaller frames like 1500, does this driver behave similar
> > (first align then add)?
>
> It can be.
> Could attached (completely untested) patch help?

Actually this patch will not help, this new one could.

diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index da62db8..1514628 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -3978,9 +3978,11 @@ e1000_alloc_rx_buffers(struct e1000_adap
buffer_info = &rx_ring->buffer_info[i];

while (cleaned_count--) {
- if (!(skb = buffer_info->skb))
+ if (!(skb = buffer_info->skb)) {
+ if (SKB_DATA_ALIGN(adapter->hw.max_frame_size) + sizeof(struct skb_shared_info) <= bufsz)
+ bufsz -= sizeof(struct skb_shared_info);
skb = dev_alloc_skb(bufsz);
- else {
+ } else {
skb_trim(skb, 0);
goto map_skb;
}

--
Evgeniy Polyakov
-
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