On Thu, Aug 03, 2006 at 05:08:51PM +0200, Krzysztof Oledzki ([email protected]) wrote:
> >>Why? After your explanation that makes sense for me. The driver needs
> >>one contiguous chunk for those 9k packet buffer and thus requests a
> >>3-order page of 16k. Or do i still do not understand this?
> >
> >Correct, except that it wants 32k.
> >e1000 logic is following:
> >align frame size to power-of-two,
> 16K?
Yep.
> >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?
diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index da62db8..cf6506d 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -3132,6 +3132,8 @@ #define MAX_STD_JUMBO_FRAME_SIZE 9234
* larger slab size
* i.e. RXBUFFER_2048 --> size-4096 slab */
+ max_frame += sizeof(struct skb_shared_info);
+
if (max_frame <= E1000_RXBUFFER_256)
adapter->rx_buffer_len = E1000_RXBUFFER_256;
else if (max_frame <= E1000_RXBUFFER_512)
@@ -3146,6 +3148,8 @@ #define MAX_STD_JUMBO_FRAME_SIZE 9234
adapter->rx_buffer_len = E1000_RXBUFFER_8192;
else if (max_frame <= E1000_RXBUFFER_16384)
adapter->rx_buffer_len = E1000_RXBUFFER_16384;
+
+ max_frame -= sizeof(struct skb_shared_info);
/* adjust allocation if LPE protects us, and we aren't using SBP */
if (!adapter->hw.tbi_compatibility_on &&
> Best regards,
>
> Krzysztof Olędzki
--
Evgeniy Polyakov
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