From: Krzysztof Halasa <[EMAIL PROTECTED]> Date: Wed, 02 Aug 2006 02:42:05 +0200
> Alexey Kuznetsov <[EMAIL PROTECTED]> writes: > > > Actually, it is historical hole in design, inherited from ancient > > times. Calling conventions of dev->hard_header() just did not allow > > to reallocate. BTW in 2.6 it can, if it uses pskb_expand_head(). > > Does that mean that hard_header() and then hard_start_xmit() > can use pskb_expand_head() instead of skb_realloc_headroom() > without restrictions? It is definitely the case that ->hard_start_xmit() can use pskb_expand_head(), some ethernet drivers even use it when they need to clobber the IP and TCP headers to implement TSO and another entity has a reference to the packet headers. Just be sure to pass GFP_ATOMIC to it in such a context. One example is drivers/net/tg3.c:tg3_start_xmit(). - 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
