On Wed, Jun 1, 2011 at 11:49 AM, Theo de Raadt <[email protected]> wrote: >> On 2011-06-01 15.53, Joel Wiramu Pauling wrote: >> > On 2 June 2011 01:41, Benny Lofgren <[email protected] >> > <mailto:[email protected]>> wrote: >> > I agree with what you are saying, and I worded this quite badly, the >> > frame I was trying to setup was "back in the day" when multi-user meant >> > something (VAX/PDP) - the load average WAS tied to core utilization - as >> > you would queue a job, and it would go into the queue and there would be >> > lots of stuff in the queue and the load average would bumo, because >> > there wasn't much core to go around. >> >> Not wanting to turn this into a pissing contest, I still have to say that >> you are fundamentally wrong about this. I'm sorry, but what you are saying >> simply is not correct. >> >> I've worked in-depth on just about every unixlike architecture there is >> since I started out in this business back in 1983, and on every single >> one (that employed it at all) the load average concept has worked >> similarly to how I described it in my previous mail. (Not always EXACTLY >> alike, but the general principle have always been the same.) >> >> The reason I'm so adamant about this is that the interpretation of the >> load average metric truly is one of the longest-standing misconceptions >> about the finer points of unix system administration there is, and if >> this discussion thread can set just one individual straight about it >> then it is worth the extra mail bandwidth. :-) > > 100% right. The load average calculation has not changed in 25 years. > Anyone who says otherwise hasn't got a single fact on their side. > > What has changed, however, is that the kernel has more kernel threads > running (for instance, ps aguxk, and look at the first few which have > the 'K' flag set in the 'STAT' field. > > Some kernels have decided to not count those threads, others do count > them. Since these kernel threads make various decisions for when to > do their next tasks and how to context switch, the statistical > monitoring of the system which ends up creating load values can get > perturbed. > > That's what this comes down to.
Which...... sounds exactly like a change in the load average calculation, due to kernel changes, that has occurred in the last 25 years.
