Date: Thu, 3 Jan 2013 23:10:01 GMT From: Johan Broman <je.broman@gmail.com> To: freebsd-bugs@FreeBSD.org Subject: Re: kern/173541: load average 0.60 at 100% idle Message-ID: <201301032310.r03NA1Tm076358@freefall.freebsd.org>
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The following reply was made to PR kern/173541; it has been noted by GNATS. From: Johan Broman <je.broman@gmail.com> To: bug-followup@freebsd.org Cc: Subject: Re: kern/173541: load average 0.60 at 100% idle Date: Fri, 4 Jan 2013 00:06:16 +0100 --047d7b5d95370023f704d26a691e Content-Type: text/plain; charset=ISO-8859-1 Hi! I see. I got around the problem in FreeBSD 9.1 by changing the clock source. Like this: # sysctl -w kern.eventtimer.timer=LAPIC The load avg dropped to 0.00 again. You can try the different clock sources available to you and see what works best. Some sources might increase the number of interrupts (like the RTC) and some might cause more context switching or CPU load. For me the LAPIC works best. You can list your clock sources using: # sysctl kern.eventtimer.choice From what I understand, measuring time can be tricky because new systems can regulate core frequency on the fly (in HW) and virtualization also increases the difficulty... It seems the order and/or weight of the clock sources has changed. When I have a chance I will reboot into the old kernel and see what has been changed. I'm totally new to FreeBSD so I don't know the normal handling of these bugs but I'll put the author of the patch on cc as well :) Good luck! Johan --047d7b5d95370023f704d26a691e Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi!<br><br>I see. I got around the problem in FreeBSD 9.1 by changing the c= lock source. Like this:<br><br># sysctl -w kern.eventtimer.timer=3DLAPIC<br= ><br>The load avg dropped to 0.00 again. You can try the different clock so= urces available to you and see what works best. Some sources might increase= the number of interrupts (like the RTC) and some might cause more context = switching or CPU load. For me the LAPIC works best. You can list your clock= sources using:<br> <br># sysctl kern.eventtimer.choice<br><br>From what I understand, measurin= g time can be tricky because new systems can regulate core frequency on the= fly (in HW) and virtualization also increases the difficulty...<br><br> It seems the order and/or weight of the clock sources has changed. When I h= ave a chance I will reboot into the old kernel and see what has been change= d. I'm totally new to FreeBSD so I don't know the normal handling o= f these bugs but I'll put the author of the patch on cc as well :)<br> <br>Good luck!<br>Johan<br><br> --047d7b5d95370023f704d26a691e--
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