Commit 09f6acf2 authored Sep 10, 2015 by Arnaldo Carvalho de Melo

tools lib api cpu: Introduce cpu.[ch] to obtain cpu related information



E.g.:

 $ ./cpu__get_max_freq
 3200000

It does that, as Kan's patch does, by looking at these files:

  $ cat /sys/devices/system/cpu/online
  0-3
  $ ./sysfs__read_ull
  devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq
  /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq=3200000
  $

I.e. find out the first online CPU, then read its cpufreq info.

But do it in tools/lib/api/, so that other tools/ living code can use
it, not just perf.

Based-on-a-patch-by: Kan Liang <kan.liang@intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-915v4cvxqplaub8qco66b9mv@git.kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent 2d729f6a

tools/lib/api/Build

+1 −0

Original line number	Diff line number	Diff line
		libapi-y += fd/
		libapi-y += fs/
		libapi-y += cpu.o

tools/lib/api/cpu.c

0 → 100644

+18 −0

Original line number	Diff line number	Diff line
		#include <stdio.h>

		#include "cpu.h"
		#include "fs/fs.h"

		int cpu__get_max_freq(unsigned long long *freq)
		{
		char entry[PATH_MAX];
		int cpu;

		if (sysfs__read_int("devices/system/cpu/online", &cpu) < 0)
		return -1;

		snprintf(entry, sizeof(entry),
		"devices/system/cpu/cpu%d/cpufreq/cpuinfo_max_freq", cpu);

		return sysfs__read_ull(entry, freq);
		}

tools/lib/api/cpu.h

0 → 100644

+6 −0

Original line number	Diff line number	Diff line
		#ifndef __API_CPU__
		#define __API_CPU__

		int cpu__get_max_freq(unsigned long long *freq);

		#endif /* __API_CPU__ */