Re: [PATCH 0/8 net-next-2.6] udp: optimisations

[Octavian Purdila <opurdila@ixiacom.com>]

On Monday 09 November 2009 07:37:24 you wrote:
> David Miller a écrit :
> > Looks great, all applied, thanks Eric.
> 
> Thanks David, I'll make the remaining patches too.
> 
> > I would even go so far as to say that the cutoff to the second hash
> > table should be even lower than 10, like maybe 4 or 5.
> 
> Probably, but we want to avoid the secondary way if possible,
> as this path might have to traverse two different chains.
> 
> (total of three cache line accesses to only take a look at chains
>  head/count)
> 
> Maybe we can change the heuristic to take into account this like that :
> 
> if (hslot->count > 4) {
> 	...
> 	if (hslot->count < hslot2->count * 2)
> 		goto begin_primary_hash_lookup;
> 
> This is tuning, and needs benchmarking.
> 

Eric, thanks a lot !

Lucian is currently testing it on our setup and once we iron out some IPv6 
issues we are seeing he will follow up with some numbers.