Re: [PATCH 2/3] Seperate DSACK from SACK fast path

[Baruch Even <baruch@ev-en.org>]

* David Miller <davem@davemloft.net> [070128 06:06]:
> From: Baruch Even <baruch@ev-en.org>
> Date: Sat, 27 Jan 2007 18:49:49 +0200
> 
> > Since the SACK receive cache doesn't need the data to be in host
> > order we also remove the ntohl in the checking loop.
>  ...
> > -	for (i = 0; i< num_sacks; i++) {
> > -		__u32 start_seq = ntohl(sp[i].start_seq);
> > -		__u32 end_seq =	 ntohl(sp[i].end_seq);
> > +	for (i = 0; i < num_sacks; i++) {
> > +		__u32 start_seq = sp[i].start_seq;
> > +		__u32 end_seq = sp[i].end_seq;
>  ...
> >  		}
> >  		tp->recv_sack_cache[i].start_seq = start_seq;
> >  		tp->recv_sack_cache[i].end_seq = end_seq;
> 
> Ok, and now the sack cache and the real sack blocks are
> stored in net-endian and this works out because we only
> make direct equality comparisons with the recv_sack_cache[]
> entry values?

Yes. The only comparison we do with recv_sack_cache entries is != and
that works for net-endian just fine.

The only reason recv_sack_cache was in host-order before that was that
start_seq and end_seq were used to do more before/after comparisons for
DSACK.

Baruch