Date: Mon, 18 Oct 2010 13:11:42 -0500 From: Dan Nelson <dnelson@allantgroup.com> To: Ed Maste <emaste@freebsd.org> Cc: freebsd-current@freebsd.org Subject: Re: CPU report in first line of "vmstat 1" is meaningless Message-ID: <20101018181142.GC5644@dan.emsphone.com> In-Reply-To: <20101018174331.GA80017@sandvine.com> References: <20101018174331.GA80017@sandvine.com>
next in thread | previous in thread | raw e-mail | index | archive | help
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 play, giving negative results. For example, on > one machine I see: 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 think). If the value can be calculated accurately, it should be printed. -- Dan Nelson dnelson@allantgroup.com
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20101018181142.GC5644>