On Mon, Jun 12, 2006 at 09:08:12PM +0100, Robert Watson wrote: > On Mon, 12 Jun 2006, Scott Long wrote: > > >I run a number of high-load production systems that do a lot of network > >and filesystem activity, all with HZ set to 100. It has also been shown > >in the past that certain things in the network area where not fixed to > >deal with a high HZ value, so it's possible that it's even more > >stable/reliable with an HZ value of 100. > > > >My personal opinion is that HZ should gop back down to 100 in 7-CURRENT > >immediately, and only be incremented back up when/if it's proven to be the > >right thing to do. And, I say that as someone who (errantly) pushed for > >the increase to 1000 several years ago. > > I think it's probably a good idea to do it sooner rather than later. It > may slightly negatively impact some services that rely on frequent timers > to do things like retransmit timing and the like. But I haven't done any > measurements.
As you know, but for the benefit of the list, restoring HZ=100 is often an important performance tweak on SMP systems with many CPUs because of all the sched_lock activity from statclock/hardclock, which scales with HZ and NCPUS. Kris
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