Merge branch 'tools' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6

* 'tools' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6:
  tools: create power/x86/x86_energy_perf_policy
  tools: create power/x86/turbostat
This commit is contained in:
Linus Torvalds 2011-01-12 08:39:15 -08:00
commit 1b3862798c
6 changed files with 1665 additions and 0 deletions

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turbostat : turbostat.c
clean :
rm -f turbostat
install :
install turbostat /usr/bin/turbostat
install turbostat.8 /usr/share/man/man8

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.TH TURBOSTAT 8
.SH NAME
turbostat \- Report processor frequency and idle statistics
.SH SYNOPSIS
.ft B
.B turbostat
.RB [ "\-v" ]
.RB [ "\-M MSR#" ]
.RB command
.br
.B turbostat
.RB [ "\-v" ]
.RB [ "\-M MSR#" ]
.RB [ "\-i interval_sec" ]
.SH DESCRIPTION
\fBturbostat \fP reports processor topology, frequency
and idle power state statistics on modern X86 processors.
Either \fBcommand\fP is forked and statistics are printed
upon its completion, or statistics are printed periodically.
\fBturbostat \fP
requires that the processor
supports an "invariant" TSC, plus the APERF and MPERF MSRs.
\fBturbostat \fP will report idle cpu power state residency
on processors that additionally support C-state residency counters.
.SS Options
The \fB-v\fP option increases verbosity.
.PP
The \fB-M MSR#\fP option dumps the specified 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.
The default is 5 seconds.
.PP
The \fBcommand\fP parameter forks \fBcommand\fP and upon its exit,
displays the statistics gathered since it was forked.
.PP
.SH FIELD DESCRIPTIONS
.nf
\fBpkg\fP processor package number.
\fBcore\fP processor core number.
\fBCPU\fP Linux CPU (logical processor) number.
\fB%c0\fP percent of the interval that the CPU retired instructions.
\fBGHz\fP average clock rate while the CPU was in c0 state.
\fBTSC\fP average GHz that the TSC ran during the entire interval.
\fB%c1, %c3, %c6\fP show the percentage residency in hardware core idle states.
\fB%pc3, %pc6\fP percentage residency in hardware package idle states.
.fi
.PP
.SH EXAMPLE
Without any parameters, turbostat prints out counters ever 5 seconds.
(override interval with "-i sec" option, or specify a command
for turbostat to fork).
The first row of statistics reflect the average for the entire system.
Subsequent rows show per-CPU statistics.
.nf
[root@x980]# ./turbostat
core CPU %c0 GHz TSC %c1 %c3 %c6 %pc3 %pc6
0.04 1.62 3.38 0.11 0.00 99.85 0.00 95.07
0 0 0.04 1.62 3.38 0.06 0.00 99.90 0.00 95.07
0 6 0.02 1.62 3.38 0.08 0.00 99.90 0.00 95.07
1 2 0.10 1.62 3.38 0.29 0.00 99.61 0.00 95.07
1 8 0.11 1.62 3.38 0.28 0.00 99.61 0.00 95.07
2 4 0.01 1.62 3.38 0.01 0.00 99.98 0.00 95.07
2 10 0.01 1.61 3.38 0.02 0.00 99.98 0.00 95.07
8 1 0.07 1.62 3.38 0.15 0.00 99.78 0.00 95.07
8 7 0.03 1.62 3.38 0.19 0.00 99.78 0.00 95.07
9 3 0.01 1.62 3.38 0.02 0.00 99.98 0.00 95.07
9 9 0.01 1.62 3.38 0.02 0.00 99.98 0.00 95.07
10 5 0.01 1.62 3.38 0.13 0.00 99.86 0.00 95.07
10 11 0.08 1.62 3.38 0.05 0.00 99.86 0.00 95.07
.fi
.SH VERBOSE EXAMPLE
The "-v" option adds verbosity to the output:
.nf
GenuineIntel 11 CPUID levels; family:model:stepping 0x6:2c:2 (6:44:2)
12 * 133 = 1600 MHz max efficiency
25 * 133 = 3333 MHz TSC frequency
26 * 133 = 3467 MHz max turbo 4 active cores
26 * 133 = 3467 MHz max turbo 3 active cores
27 * 133 = 3600 MHz max turbo 2 active cores
27 * 133 = 3600 MHz max turbo 1 active cores
.fi
The \fBmax efficiency\fP frequency, a.k.a. Low Frequency Mode, is the frequency
available at the minimum package voltage. The \fBTSC frequency\fP is the nominal
maximum frequency of the processor if turbo-mode were not available. This frequency
should be sustainable on all CPUs indefinitely, given nominal power and cooling.
The remaining rows show what maximum turbo frequency is possible
depending on the number of idle cores. Note that this information is
not available on all processors.
.SH FORK EXAMPLE
If turbostat is invoked with a command, it will fork that command
and output the statistics gathered when the command exits.
eg. Here a cycle soaker is run on 1 CPU (see %c0) for a few seconds
until ^C while the other CPUs are mostly idle:
.nf
[root@x980 lenb]# ./turbostat cat /dev/zero > /dev/null
^Ccore CPU %c0 GHz TSC %c1 %c3 %c6 %pc3 %pc6
8.49 3.63 3.38 16.23 0.66 74.63 0.00 0.00
0 0 1.22 3.62 3.38 32.18 0.00 66.60 0.00 0.00
0 6 0.40 3.61 3.38 33.00 0.00 66.60 0.00 0.00
1 2 0.11 3.14 3.38 0.19 3.95 95.75 0.00 0.00
1 8 0.05 2.88 3.38 0.25 3.95 95.75 0.00 0.00
2 4 0.00 3.13 3.38 0.02 0.00 99.98 0.00 0.00
2 10 0.00 3.09 3.38 0.02 0.00 99.98 0.00 0.00
8 1 0.04 3.50 3.38 14.43 0.00 85.54 0.00 0.00
8 7 0.03 2.98 3.38 14.43 0.00 85.54 0.00 0.00
9 3 0.00 3.16 3.38 100.00 0.00 0.00 0.00 0.00
9 9 99.93 3.63 3.38 0.06 0.00 0.00 0.00 0.00
10 5 0.01 2.82 3.38 0.08 0.00 99.91 0.00 0.00
10 11 0.02 3.36 3.38 0.06 0.00 99.91 0.00 0.00
6.950866 sec
.fi
Above the cycle soaker drives cpu9 up 3.6 Ghz turbo limit
while the other processors are generally in various states of idle.
Note that cpu3 is an HT sibling sharing core9
with cpu9, and thus it is unable to get to an idle state
deeper than c1 while cpu9 is busy.
Note that turbostat reports average GHz of 3.61, while
the arithmetic average of the GHz column above is 3.24.
This is a weighted average, where the weight is %c0. ie. it is the total number of
un-halted cycles elapsed per time divided by the number of CPUs.
.SH NOTES
.B "turbostat "
must be run as root.
.B "turbostat "
reads hardware counters, but doesn't write them.
So it will not interfere with the OS or other programs, including
multiple invocations of itself.
\fBturbostat \fP
may work poorly on Linux-2.6.20 through 2.6.29,
as \fBacpi-cpufreq \fPperiodically cleared the APERF and MPERF
in those kernels.
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.
.SH REFERENCES
"Intel® Turbo Boost Technology
in Intel® Core™ Microarchitecture (Nehalem) Based Processors"
http://download.intel.com/design/processor/applnots/320354.pdf
"Intel® 64 and IA-32 Architectures Software Developer's Manual
Volume 3B: System Programming Guide"
http://www.intel.com/products/processor/manuals/
.SH FILES
.ta
.nf
/dev/cpu/*/msr
.fi
.SH "SEE ALSO"
msr(4), vmstat(8)
.PP
.SH AUTHORS
.nf
Written by Len Brown <len.brown@intel.com>

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x86_energy_perf_policy : x86_energy_perf_policy.c
clean :
rm -f x86_energy_perf_policy
install :
install x86_energy_perf_policy /usr/bin/
install x86_energy_perf_policy.8 /usr/share/man/man8/

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.\" This page Copyright (C) 2010 Len Brown <len.brown@intel.com>
.\" Distributed under the GPL, Copyleft 1994.
.TH X86_ENERGY_PERF_POLICY 8
.SH NAME
x86_energy_perf_policy \- read or write MSR_IA32_ENERGY_PERF_BIAS
.SH SYNOPSIS
.ft B
.B x86_energy_perf_policy
.RB [ "\-c cpu" ]
.RB [ "\-v" ]
.RB "\-r"
.br
.B x86_energy_perf_policy
.RB [ "\-c cpu" ]
.RB [ "\-v" ]
.RB 'performance'
.br
.B x86_energy_perf_policy
.RB [ "\-c cpu" ]
.RB [ "\-v" ]
.RB 'normal'
.br
.B x86_energy_perf_policy
.RB [ "\-c cpu" ]
.RB [ "\-v" ]
.RB 'powersave'
.br
.B x86_energy_perf_policy
.RB [ "\-c cpu" ]
.RB [ "\-v" ]
.RB n
.br
.SH DESCRIPTION
\fBx86_energy_perf_policy\fP
allows software to convey
its policy for the relative importance of performance
versus energy savings to the processor.
The processor uses this information in model-specific ways
when it must select trade-offs between performance and
energy efficiency.
This policy hint does not supersede Processor Performance states
(P-states) or CPU Idle power states (C-states), but allows
software to have influence where it would otherwise be unable
to express a preference.
For example, this setting may tell the hardware how
aggressively or conservatively to control frequency
in the "turbo range" above the explicitly OS-controlled
P-state frequency range. It may also tell the hardware
how aggressively is should enter the OS requested C-states.
Support for this feature is indicated by CPUID.06H.ECX.bit3
per the Intel Architectures Software Developer's Manual.
.SS Options
\fB-c\fP limits operation to a single CPU.
The default is to operate on all CPUs.
Note that MSR_IA32_ENERGY_PERF_BIAS is defined per
logical processor, but that the initial implementations
of the MSR were shared among all processors in each package.
.PP
\fB-v\fP increases verbosity. By default
x86_energy_perf_policy is silent.
.PP
\fB-r\fP is for "read-only" mode - the unchanged state
is read and displayed.
.PP
.I performance
Set a policy where performance is paramount.
The processor will be unwilling to sacrifice any performance
for the sake of energy saving. This is the hardware default.
.PP
.I normal
Set a policy with a normal balance between performance and energy efficiency.
The processor will tolerate minor performance compromise
for potentially significant energy savings.
This reasonable default for most desktops and servers.
.PP
.I powersave
Set a policy where the processor can accept
a measurable performance hit to maximize energy efficiency.
.PP
.I n
Set MSR_IA32_ENERGY_PERF_BIAS to the specified number.
The range of valid numbers is 0-15, where 0 is maximum
performance and 15 is maximum energy efficiency.
.SH NOTES
.B "x86_energy_perf_policy "
runs only as root.
.SH FILES
.ta
.nf
/dev/cpu/*/msr
.fi
.SH "SEE ALSO"
msr(4)
.PP
.SH AUTHORS
.nf
Written by Len Brown <len.brown@intel.com>

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/*
* x86_energy_perf_policy -- set the energy versus performance
* policy preference bias on recent X86 processors.
*/
/*
* Copyright (c) 2010, Intel Corporation.
* Len Brown <len.brown@intel.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/resource.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/time.h>
#include <stdlib.h>
#include <string.h>
unsigned int verbose; /* set with -v */
unsigned int read_only; /* set with -r */
char *progname;
unsigned long long new_bias;
int cpu = -1;
/*
* Usage:
*
* -c cpu: limit action to a single CPU (default is all CPUs)
* -v: verbose output (can invoke more than once)
* -r: read-only, don't change any settings
*
* performance
* Performance is paramount.
* Unwilling to sacrafice any performance
* for the sake of energy saving. (hardware default)
*
* normal
* Can tolerate minor performance compromise
* for potentially significant energy savings.
* (reasonable default for most desktops and servers)
*
* powersave
* Can tolerate significant performance hit
* to maximize energy savings.
*
* n
* a numerical value to write to the underlying MSR.
*/
void usage(void)
{
printf("%s: [-c cpu] [-v] "
"(-r | 'performance' | 'normal' | 'powersave' | n)\n",
progname);
exit(1);
}
#define MSR_IA32_ENERGY_PERF_BIAS 0x000001b0
#define BIAS_PERFORMANCE 0
#define BIAS_BALANCE 6
#define BIAS_POWERSAVE 15
void cmdline(int argc, char **argv)
{
int opt;
progname = argv[0];
while ((opt = getopt(argc, argv, "+rvc:")) != -1) {
switch (opt) {
case 'c':
cpu = atoi(optarg);
break;
case 'r':
read_only = 1;
break;
case 'v':
verbose++;
break;
default:
usage();
}
}
/* if -r, then should be no additional optind */
if (read_only && (argc > optind))
usage();
/*
* if no -r , then must be one additional optind
*/
if (!read_only) {
if (argc != optind + 1) {
printf("must supply -r or policy param\n");
usage();
}
if (!strcmp("performance", argv[optind])) {
new_bias = BIAS_PERFORMANCE;
} else if (!strcmp("normal", argv[optind])) {
new_bias = BIAS_BALANCE;
} else if (!strcmp("powersave", argv[optind])) {
new_bias = BIAS_POWERSAVE;
} else {
char *endptr;
new_bias = strtoull(argv[optind], &endptr, 0);
if (endptr == argv[optind] ||
new_bias > BIAS_POWERSAVE) {
fprintf(stderr, "invalid value: %s\n",
argv[optind]);
usage();
}
}
}
}
/*
* validate_cpuid()
* returns on success, quietly exits on failure (make verbose with -v)
*/
void validate_cpuid(void)
{
unsigned int eax, ebx, ecx, edx, max_level;
char brand[16];
unsigned int fms, family, model, stepping;
eax = ebx = ecx = edx = 0;
asm("cpuid" : "=a" (max_level), "=b" (ebx), "=c" (ecx),
"=d" (edx) : "a" (0));
if (ebx != 0x756e6547 || edx != 0x49656e69 || ecx != 0x6c65746e) {
if (verbose)
fprintf(stderr, "%.4s%.4s%.4s != GenuineIntel",
(char *)&ebx, (char *)&edx, (char *)&ecx);
exit(1);
}
asm("cpuid" : "=a" (fms), "=c" (ecx), "=d" (edx) : "a" (1) : "ebx");
family = (fms >> 8) & 0xf;
model = (fms >> 4) & 0xf;
stepping = fms & 0xf;
if (family == 6 || family == 0xf)
model += ((fms >> 16) & 0xf) << 4;
if (verbose > 1)
printf("CPUID %s %d levels family:model:stepping "
"0x%x:%x:%x (%d:%d:%d)\n", brand, max_level,
family, model, stepping, family, model, stepping);
if (!(edx & (1 << 5))) {
if (verbose)
printf("CPUID: no MSR\n");
exit(1);
}
/*
* Support for MSR_IA32_ENERGY_PERF_BIAS
* is indicated by CPUID.06H.ECX.bit3
*/
asm("cpuid" : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx) : "a" (6));
if (verbose)
printf("CPUID.06H.ECX: 0x%x\n", ecx);
if (!(ecx & (1 << 3))) {
if (verbose)
printf("CPUID: No MSR_IA32_ENERGY_PERF_BIAS\n");
exit(1);
}
return; /* success */
}
unsigned long long get_msr(int cpu, int offset)
{
unsigned long long msr;
char msr_path[32];
int retval;
int fd;
sprintf(msr_path, "/dev/cpu/%d/msr", cpu);
fd = open(msr_path, O_RDONLY);
if (fd < 0) {
printf("Try \"# modprobe msr\"\n");
perror(msr_path);
exit(1);
}
retval = pread(fd, &msr, sizeof msr, offset);
if (retval != sizeof msr) {
printf("pread cpu%d 0x%x = %d\n", cpu, offset, retval);
exit(-2);
}
close(fd);
return msr;
}
unsigned long long put_msr(int cpu, unsigned long long new_msr, int offset)
{
unsigned long long old_msr;
char msr_path[32];
int retval;
int fd;
sprintf(msr_path, "/dev/cpu/%d/msr", cpu);
fd = open(msr_path, O_RDWR);
if (fd < 0) {
perror(msr_path);
exit(1);
}
retval = pread(fd, &old_msr, sizeof old_msr, offset);
if (retval != sizeof old_msr) {
perror("pwrite");
printf("pread cpu%d 0x%x = %d\n", cpu, offset, retval);
exit(-2);
}
retval = pwrite(fd, &new_msr, sizeof new_msr, offset);
if (retval != sizeof new_msr) {
perror("pwrite");
printf("pwrite cpu%d 0x%x = %d\n", cpu, offset, retval);
exit(-2);
}
close(fd);
return old_msr;
}
void print_msr(int cpu)
{
printf("cpu%d: 0x%016llx\n",
cpu, get_msr(cpu, MSR_IA32_ENERGY_PERF_BIAS));
}
void update_msr(int cpu)
{
unsigned long long previous_msr;
previous_msr = put_msr(cpu, new_bias, MSR_IA32_ENERGY_PERF_BIAS);
if (verbose)
printf("cpu%d msr0x%x 0x%016llx -> 0x%016llx\n",
cpu, MSR_IA32_ENERGY_PERF_BIAS, previous_msr, new_bias);
return;
}
char *proc_stat = "/proc/stat";
/*
* run func() on every cpu in /dev/cpu
*/
void for_every_cpu(void (func)(int))
{
FILE *fp;
int retval;
fp = fopen(proc_stat, "r");
if (fp == NULL) {
perror(proc_stat);
exit(1);
}
retval = fscanf(fp, "cpu %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d\n");
if (retval != 0) {
perror("/proc/stat format");
exit(1);
}
while (1) {
int cpu;
retval = fscanf(fp,
"cpu%u %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d\n",
&cpu);
if (retval != 1)
return;
func(cpu);
}
fclose(fp);
}
int main(int argc, char **argv)
{
cmdline(argc, argv);
if (verbose > 1)
printf("x86_energy_perf_policy Nov 24, 2010"
" - Len Brown <lenb@kernel.org>\n");
if (verbose > 1 && !read_only)
printf("new_bias %lld\n", new_bias);
validate_cpuid();
if (cpu != -1) {
if (read_only)
print_msr(cpu);
else
update_msr(cpu);
} else {
if (read_only)
for_every_cpu(print_msr);
else
for_every_cpu(update_msr);
}
return 0;
}