CPU report in first line of "vmstat 1" is meaningless

2010-10-18 Thread Ed Maste
The us/sy/id CPU usage numbers in the first line of vmstat are not useful, because they're calculated based on kern.cp_times since boot, and not a delta as are all subsequent lines. If the system has been up long enough wrapping may come in to play, giving negative results. For example, on one ma

Re: CPU report in first line of "vmstat 1" is meaningless

2010-10-18 Thread Dan Nelson
In the last episode (Oct 18), Ed Maste said: > The us/sy/id CPU usage numbers in the first line of vmstat are not useful, > because they're calculated based on kern.cp_times since boot, and not a > delta as are all subsequent lines. If the system has been up long enough > wrapping may come in to p

Re: CPU report in first line of "vmstat 1" is meaningless

2010-10-18 Thread Ed Maste
On Mon, Oct 18, 2010 at 01:11:42PM -0500, Dan Nelson wrote: > Maybe only blank it out on 32-bit machines? It's a long, and a 64-bit > cp_time value essentially won't roll over (at 1 billion increments per > second it will roll over in 500 years; we currently increment 133 times per > second, I th

Re: CPU report in first line of "vmstat 1" is meaningless

2010-10-18 Thread Dan Nelson
In the last episode (Oct 18), Ed Maste said: > On Mon, Oct 18, 2010 at 01:11:42PM -0500, Dan Nelson wrote: > > Maybe only blank it out on 32-bit machines? It's a long, and a 64-bit > > cp_time value essentially won't roll over (at 1 billion increments per > > second it will roll over in 500 years;

Re: CPU report in first line of "vmstat 1" is meaningless

2010-10-18 Thread Alexander Best
On Mon Oct 18 10, Dan Nelson wrote: > In the last episode (Oct 18), Ed Maste said: > > On Mon, Oct 18, 2010 at 01:11:42PM -0500, Dan Nelson wrote: > > > Maybe only blank it out on 32-bit machines? It's a long, and a 64-bit > > > cp_time value essentially won't roll over (at 1 billion increments pe

Re: CPU report in first line of "vmstat 1" is meaningless

2010-10-18 Thread Alexander Best
On Mon Oct 18 10, Dan Nelson wrote: > In the last episode (Oct 18), Ed Maste said: > > On Mon, Oct 18, 2010 at 01:11:42PM -0500, Dan Nelson wrote: > > > Maybe only blank it out on 32-bit machines? It's a long, and a 64-bit > > > cp_time value essentially won't roll over (at 1 billion increments pe

Re: CPU report in first line of "vmstat 1" is meaningless

2010-10-19 Thread John Baldwin
On Monday, October 18, 2010 3:30:11 pm Ed Maste wrote: > On Mon, Oct 18, 2010 at 01:11:42PM -0500, Dan Nelson wrote: > > > Maybe only blank it out on 32-bit machines? It's a long, and a 64-bit > > cp_time value essentially won't roll over (at 1 billion increments per > > second it will roll over

Re: CPU report in first line of "vmstat 1" is meaningless

2010-10-19 Thread Lars Engels
On Tue, Oct 19, 2010 at 08:54:38AM -0400, John Baldwin wrote: > On Monday, October 18, 2010 3:30:11 pm Ed Maste wrote: > > On Mon, Oct 18, 2010 at 01:11:42PM -0500, Dan Nelson wrote: > > > > > Maybe only blank it out on 32-bit machines? It's a long, and a 64-bit > > > cp_time value essentially wo

Re: CPU report in first line of "vmstat 1" is meaningless

2010-10-19 Thread John Baldwin
On Tuesday, October 19, 2010 10:40:56 am Lars Engels wrote: > On Tue, Oct 19, 2010 at 08:54:38AM -0400, John Baldwin wrote: > > On Monday, October 18, 2010 3:30:11 pm Ed Maste wrote: > > > On Mon, Oct 18, 2010 at 01:11:42PM -0500, Dan Nelson wrote: > > > > > > > Maybe only blank it out on 32-bit m

Re: CPU report in first line of "vmstat 1" is meaningless

2010-10-19 Thread Matthew Dillon
:> :> > On a related note I'm not sure if it makes sense to have the same :> > behaviour for the first line when an interval is set as when it is :> > invoked with no interval. : :...also vmstat seems to exist in a few other OSes (linux e.g). maybe they've :fixed it already (or the netbsd/openbsd/