diff options
Diffstat (limited to 'tools/power/x86/turbostat/turbostat.8')
| -rw-r--r-- | tools/power/x86/turbostat/turbostat.8 | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/tools/power/x86/turbostat/turbostat.8 b/tools/power/x86/turbostat/turbostat.8 index 74e44507dfe..8e7b29af78f 100644 --- a/tools/power/x86/turbostat/turbostat.8 +++ b/tools/power/x86/turbostat/turbostat.8 @@ -6,12 +6,14 @@ turbostat \- Report processor frequency and idle statistics .B turbostat .RB [ "\-s" ] .RB [ "\-v" ] +.RB [ "\-m MSR#" ] .RB [ "\-M MSR#" ] .RB command .br .B turbostat .RB [ "\-s" ] .RB [ "\-v" ] +.RB [ "\-m MSR#" ] .RB [ "\-M MSR#" ] .RB [ "\-i interval_sec" ] .SH DESCRIPTION @@ -35,7 +37,10 @@ The \fB-p\fP option limits output to the 1st thread in each package. .PP The \fB-v\fP option increases verbosity. .PP -The \fB-M MSR#\fP option dumps the specified MSR, +The \fB-m MSR#\fP option dumps the specified 32-bit MSR, +in addition to the usual frequency and idle statistics. +.PP +The \fB-M MSR#\fP option dumps the specified 64-bit MSR, in addition to the usual frequency and idle statistics. .PP The \fB-i interval_sec\fP option prints statistics every \fiinterval_sec\fP seconds. @@ -165,6 +170,13 @@ may work poorly on Linux-2.6.20 through 2.6.29, as \fBacpi-cpufreq \fPperiodically cleared the APERF and MPERF in those kernels. +If the TSC column does not make sense, then +the other numbers will also make no sense. +Turbostat is lightweight, and its data collection is not atomic. +These issues are usually caused by an extremely short measurement +interval (much less than 1 second), or system activity that prevents +turbostat from being able to run on all CPUS to quickly collect data. + The APERF, MPERF MSRs are defined to count non-halted cycles. Although it is not guaranteed by the architecture, turbostat assumes that they count at TSC rate, which is true on all processors tested to date. |