On Tue, Feb 02, 2010 at 06:15:50PM +0100, Thomas Treutner wrote:
Hi,
I've written a little patch to fix wrong nodeinfo->mhz when the Linux kernel module cpufreq and a typical governor like ondemand are loaded. nodeinfo->mhz is then too low as libvirt just reads /proc/cpuinfo, entry "cpu MHz". This patch reads
/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
if existing and corrects nodeinfo->mhz if the value found is higher. Using cpu0 is a crude hack but as discussed on IRC, considering different governors/maximum frequencies per cpu/core would require changing the nodeinfo struct, which would break the API.
Right, just checked on my laptop (idle) and got cpu MHz : 800.000 while /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq indicates a 2.2GHz model, we really need to fix this
Some more info: https://bugzilla.redhat.com/show_bug.cgi?id=559762
Please have a careful look at my patch, my last C is quite some time ago. I tried to stick to linuxNodeInfoCPUPopulate, but f.e., checking for "&& *p == '\0'" after virStrToLong_ui doesn't work and I'm wondering why scaling_max_freq may not be terminated with by NUL? I also hope the file handling is correct, but please have a look.
There is still some todo: Some logging would be helpful, maybe one of you could point out which function best to use?
This is my first patch, so hopefully it follows in the next mail ;-)
Okay, we will review but this clearly need to be fixed :-) thanks ! Daniel -- Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/ daniel@veillard.com | Rpmfind RPM search engine http://rpmfind.net/ http://veillard.com/ | virtualization library http://libvirt.org/