tools/power turbostat: add [-m MSR#] option
-m MSR# prints the specified MSR in 32-bit format
-M MSR# prints the specified MSR in 64-bit format
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/tools/power/x86/turbostat/turbostat.8 b/tools/power/x86/turbostat/turbostat.8
index 74e4450..8e7b29af 100644
--- a/tools/power/x86/turbostat/turbostat.8
+++ b/tools/power/x86/turbostat/turbostat.8
@@ -6,12 +6,14 @@
.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 @@
.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 @@
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.