On Mon, 30 Jul 2007 18:50:28 -0700 (PDT) David Miller <[EMAIL PROTECTED]> wrote:
> > Stephen Rothwell pointed out to me that the skb_frag_struct > is broken on platforms using 64K or larger page sizes, it > even generates warnings when (for example) the myri10ge driver > tries to assign PAGE_SIZE into frag->size. > > I've thus increased page offset and size to __u32 in the patch below. > > I made this change much to even my own chagrin, but this is the > most direct fix and the ifdefs we could put here are both ugly > and also not something that we do with struct scatterlist so > no reason to do it in a place like this. > > Actually, the cost on 64-bit is zero because there existed 4 bytes of > alignment padding for skb_frag_struct because of the page pointer. > On 32-bit the cost is up to 64-bytes :-/ > > Stephen, this opens up the doors a bit for the scatterlist work > you wanted to do in sk_buff. > Ouch... sizeof(struct skb_shared_info) is enlarged by 18*4 bytes on i386, a litle bit more than 64 bytes :( I understand ifdefs are ugly, but in the common case (PAGE_SIZE<64K), this change seems very unfortunate. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
