Re: [libvirt] [PATCH 1/2] Get cpuMhz of virNodeGetInfo() from cpufreq/cpuinfo_max_freq, if exist

Hi, Eric On Mon, 31 Jan 2011 15:46:39 -0700 Eric Blake <eblake(a)redhat.com&gt; wrote: > On 01/27/2011 02:51 AM, Minoru Usui wrote: > > virNodeGetInfo() gets from > > /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq, first. > > > > Signed-off-by: Minoru Usui <usui(a)mxm.nes.nec.co.jp&gt; > > I haven't looked closely at this series yet... > > > + /* > > + * nodeinfo->mhz should return maximum frequency, > > + * but "cpu MHz" of /proc/cpuinfo is scaled by power saving feature. > > + * So it gets cpufreq/cpuinfo_max_freq, if possible. > > + */ > > + ret = get_cpu_value(0, "cpufreq/cpuinfo_max_freq", true); > > + if (ret < 0) > > + return -1; > > + else if (ret != 1) { > > + /* convert unit */ > > + cpu_mhz = ret / 1000; > > But which units is this converting between, and should it truncate or > round up? I think it divide by 1000 is collect, because my machine returns below values. ----------------------------------------------------------------- # cat /sys/devices/system/cpu/cpu?/cpufreq/cpuinfo_max_freq 2333331 2333331 2333331 2333331 2333331 2333331 2333331 2333331 # grep 'cpu MHz' /proc/cpuinfo cpu MHz : 2333.331 cpu MHz : 2333.331 cpu MHz : 2333.331 cpu MHz : 2333.331 cpu MHz : 2333.331 cpu MHz : 2333.331 cpu MHz : 2333.331 cpu MHz : 2333.331 ----------------------------------------------------------------- On the other hand, I don't have clear opinion about truncate or round up. Present implementation of linuxNodeInfoCPUPopulate() selects truncate, so I implement to truncate logic.