On 4-6-2011 0:04, Stuart Henderson wrote: > On 2011-06-03, Eric K. Miller <[email protected]> wrote: >>> Are you running -current? There have been some massive tweaks in >> networking performance in -current. Try out and report back. >> >> We were running 4.7 amd64 version (GENERIC.MP). Also tried the single >> processor version. >> >> Intel Pro/1000 MT cards were used. >> >> I should mention that we had a large number of virtual interfaces (300+) >> for routing traffic among these VLANs. So maybe this was the cause. > > after 4.9 we switched to an RB tree for local address lookups, > I think this is likely to help that situation. > > there is also a hash and sequentially-searched list used for vlan > tag lookup; dlg looked at replacing it with an RB tree before, iirc > it made things worse on some machines (probably those with microscopic > caches) but it's probably worth re-checking that...
A simpler option may be to bump the hash size (TAG_HASH_SIZE) which only has 32 buckets now. Maybe even to 4096.
