Messages in this thread | | | Date | Wed, 27 Aug 2008 00:51:58 +0400 | From | Evgeniy Polyakov <> | Subject | Re: loaded router, excessive getnstimeofday in oprofile |
| |
On Tue, Aug 26, 2008 at 10:44:56PM +0200, Eric Dumazet (dada1@cosmosbay.com) wrote: > >Do you have any packet sockets in this system? Like running dhcp daemon? > > > > Another way to see this problem can be to start a sniffer on the machine, > even with a restrictive pcap filter, to check if performance change or not. > (It should decrease)
Or just check /proc/net/packet iirc. Anyway, having at least one packet socket ends up with timestamping of each packet, so you will get fair load of getnstimeofday() in that case.
> For example, I believe that running "ping" could have the same effect > (increasing netstamp_needed variable : every incoming packet has to be > timestamped) > > So beware of pings, traceroute and other networking tools...
Yup, this innocent toys can end up with this such behaviour on modern highly loaded machines.
-- Evgeniy Polyakov
| |