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Processor performance question [hardware]
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MPSTAT(1) Linux User's Manual MPSTAT(1) NAME
mpstat - Report processors related statistics. SYNOPSIS
mpstat [ -A ] [ -I { SUM | CPU | SCPU | ALL } ] [ -u ] [ -P { cpu [,...] | ON | ALL } ] [ -V ] [ interval [ count ] ] DESCRIPTION
The mpstat command writes to standard output activities for each available processor, processor 0 being the first one. Global average activities among all processors are also reported. The mpstat command can be used both on SMP and UP machines, but in the latter, only global average activities will be printed. If no activity has been selected, then the default report is the CPU utilization report. The interval parameter specifies the amount of time in seconds between each report. A value of 0 (or no parameters at all) indicates that processors statistics are to be reported for the time since system startup (boot). The count parameter can be specified in conjunction with the interval parameter if this one is not set to zero. The value of count determines the number of reports generated at interval sec- onds apart. If the interval parameter is specified without the count parameter, the mpstat command generates reports continuously. OPTIONS
-A This option is equivalent to specifying -I ALL -u -P ALL -I { SUM | CPU | SCPU | ALL } Report interrupts statistics. With the SUM keyword, the mpstat command reports the total number of interrupts per processor. The following values are displayed: CPU Processor number. The keyword all indicates that statistics are calculated as averages among all processors. intr/s Show the total number of interrupts received per second by the CPU or CPUs. With the CPU keyword, the number of each individual interrupt received per second by the CPU or CPUs is displayed. With the SCPU keyword, the number of each individual software interrupt received per second by the CPU or CPUs is displayed. This option works only with kernels 2.6.31 and later. The ALL keyword is equivalent to specifying all the keywords above and therefore all the interrupts statistics are displayed. -P { cpu [,...] | ON | ALL } Indicate the processor number for which statistics are to be reported. cpu is the processor number. Note that processor 0 is the first processor. The ON keyword indicates that statistics are to be reported for every online processor, whereas the ALL keyword indicates that statistics are to be reported for all processors. -u Report CPU utilization. The following values are displayed: CPU Processor number. The keyword all indicates that statistics are calculated as averages among all processors. %usr Show the percentage of CPU utilization that occurred while executing at the user level (application). %nice Show the percentage of CPU utilization that occurred while executing at the user level with nice priority. %sys Show the percentage of CPU utilization that occurred while executing at the system level (kernel). Note that this does not include time spent servicing hardware and software interrupts. %iowait Show the percentage of time that the CPU or CPUs were idle during which the system had an outstanding disk I/O request. %irq Show the percentage of time spent by the CPU or CPUs to service hardware interrupts. %soft Show the percentage of time spent by the CPU or CPUs to service software interrupts. %steal Show the percentage of time spent in involuntary wait by the virtual CPU or CPUs while the hypervisor was servicing another virtual processor. %guest Show the percentage of time spent by the CPU or CPUs to run a virtual processor. %idle Show the percentage of time that the CPU or CPUs were idle and the system did not have an outstanding disk I/O request. Note: On SMP machines a processor that does not have any activity at all is a disabled (offline) processor. -V Print version number then exit. ENVIRONMENT
The mpstat command takes into account the following environment variable: S_TIME_FORMAT If this variable exists and its value is ISO then the current locale will be ignored when printing the date in the report header. The mpstat command will use the ISO 8601 format (YYYY-MM-DD) instead. EXAMPLES
mpstat 2 5 Display five reports of global statistics among all processors at two second intervals. mpstat -P ALL 2 5 Display five reports of statistics for all processors at two second intervals. BUGS
/proc filesystem must be mounted for the mpstat command to work. Only a few activities are given by the Linux kernel for each processor. FILES
/proc contains various files with system statistics. AUTHOR
Sebastien Godard (sysstat <at> orange.fr) SEE ALSO
sar(1), pidstat(1), iostat(1), vmstat(8) http://pagesperso-orange.fr/sebastien.godard/ Linux AUGUST 2011 MPSTAT(1)
