From: Baruch Even <[EMAIL PROTECTED]>
Date: Thu, 1 Feb 2007 09:22:52 +0200
> * David Miller <[EMAIL PROTECTED]> [070131 22:52]:
> > We should never see a SACK block from sequence zero to zero,
> > which would be an empty SACK block.
>
> That would work as well at the cost of extra writing to memory for each
> ack packet. Though I won't guess what is worse, the extra memory used or
> the extra writing.
Good point. The recv_sack_cache is 32-bytes, so sits in at most
2 cache lines. The writes are consequetive and in order so would
compress into cpu store buffers.
But it's definitely not free. :-)
> > Something like the following?
> >
> > diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
> > index c26076f..84cd722 100644
> > --- a/net/ipv4/tcp_input.c
> > +++ b/net/ipv4/tcp_input.c
> > @@ -999,6 +1001,10 @@ tcp_sacktag_write_queue(struct sock *sk, struct
> > sk_buff *ack_skb, u32 prior_snd_
> > return 0;
> > }
> > }
> > + for (; i <= 4; i++) {
>
> That won't work though, the <= should be <, I've actually used
> ARRAY_SIZE just to be on the safe side.
Thanks for catching that.
-
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
