From: Arnaldo Carvalho de Melo <[email protected]> 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 <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: David Ahern <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Kan Liang <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Wang Nan <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> --- tools/lib/api/Build | 1 + tools/lib/api/cpu.c | 18 ++++++++++++++++++ tools/lib/api/cpu.h | 6 ++++++ 3 files changed, 25 insertions(+) create mode 100644 tools/lib/api/cpu.c create mode 100644 tools/lib/api/cpu.h diff --git a/tools/lib/api/Build b/tools/lib/api/Build index 3653965cf481..e8b8a23b9bf4 100644 --- a/tools/lib/api/Build +++ b/tools/lib/api/Build @@ -1,2 +1,3 @@ libapi-y += fd/ libapi-y += fs/ +libapi-y += cpu.o diff --git a/tools/lib/api/cpu.c b/tools/lib/api/cpu.c new file mode 100644 index 000000000000..8c6489356e3a --- /dev/null +++ b/tools/lib/api/cpu.c @@ -0,0 +1,18 @@ +#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); +} diff --git a/tools/lib/api/cpu.h b/tools/lib/api/cpu.h new file mode 100644 index 000000000000..81e9d3955961 --- /dev/null +++ b/tools/lib/api/cpu.h @@ -0,0 +1,6 @@ +#ifndef __API_CPU__ +#define __API_CPU__ + +int cpu__get_max_freq(unsigned long long *freq); + +#endif /* __API_CPU__ */ -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
