Difference between revisions of "Vestat"
m (fix tipography a bit) |
(let's meet reality when converting measures) |
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Using cycles: | Using cycles: | ||
| − | *seconds = ''measurement'' / | + | *seconds = ''measurement'' / frequency_of_your_cpu |
Variables: | Variables: | ||
| − | * ''jiffies_per_second'' = 1000 '''(unless you have changed that in kernel config | + | * ''jiffies_per_second'' = 1000 '''(more often ''100'', unless you have changed that in kernel config, check CONFIG_HZ= in kernel .config or /proc/config.gz)''' |
* ''cycles_per_jiffy'' = ''frequency_of_your_cpu'' / ''jiffies_per_second'' | * ''cycles_per_jiffy'' = ''frequency_of_your_cpu'' / ''jiffies_per_second'' | ||
* ''frequency_of_your_cpu'' (in Hz) can be read from /proc/cpuinfo, as: | * ''frequency_of_your_cpu'' (in Hz) can be read from /proc/cpuinfo, as: | ||
| − | ** <code>cpu MHz : '' | + | ** <code>cpu MHz : ''megahertz''</code>, and thus ''frequency_of_your_cpu'' = ''megahertz'' * 1048576 (for multiCPU machines this is based on the speed of one cpu only) |
Revision as of 15:50, 23 March 2009
The /proc/vz/vestat file contains statistics for VE CPU usage.
The guessed content (may the Gods - blessed thy fingers - acknowledge or reject my humble info here):
- VEID: The VE ID, obviously.
- user, nice, system, uptime: usage in jiffies. These are the equivalents of
/proc/stat, but there is no idle because it cannot be measured this way. - idle, strv, uptime, used: usage in cycles. idle and uptime are obvious, strv isn't used, and used is the used cycles by VE on all CPUs.
- maxlat, totlat, numsched: latency statistics in cycles. maxlat is max latency in cycles meaning how long VE process has to wait before it actually got CPU time; totlat/numsched gives average scheduling latency. These do not seem work in OpenVZ, only in Virtuozzo.
Measure conversions
Using jiffies:
- seconds = measurement / jiffies_per_seconds
Using cycles:
- seconds = measurement / frequency_of_your_cpu
Variables:
- jiffies_per_second = 1000 (more often 100, unless you have changed that in kernel config, check CONFIG_HZ= in kernel .config or /proc/config.gz)
- cycles_per_jiffy = frequency_of_your_cpu / jiffies_per_second
- frequency_of_your_cpu (in Hz) can be read from /proc/cpuinfo, as:
cpu MHz : megahertz, and thus frequency_of_your_cpu = megahertz * 1048576 (for multiCPU machines this is based on the speed of one cpu only)
