Powertop 2.3 fails to run on machine with > 69 CPUs because system open files limitation of one process is 1024 default, While powertop will open one file for every monitored perf_event (at least 15) each CPU. Like on 80 CPUs Westmere-EX machine, powertop will fail to run with below: PowerTOP v2.3 needs the kernel to support the 'perf' subsystem as well as support for trace points in the kernel: CONFIG_PERF_EVENTS=y CONFIG_PERF_COUNTERS=y CONFIG_TRACEPOINTS=y CONFIG_TRACING=y This patch is to change RLIMIT_NOFILE from default (1024) to max limition. Signed-off-by: Youquan Song <youquan.song(a)intel.com&gt; --- src/main.cpp | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/src/main.cpp b/src/main.cpp index 0883424..8cd97a2 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -36,6 +36,7 @@ #include <getopt.h> #include <unistd.h> #include <locale.h> +#include <sys/resource.h> #include "cpu/cpu.h" #include "process/process.h" @@ -283,9 +284,14 @@ static void powertop_init(void) static char initialized = 0; int ret; struct statfs st_fs; + struct rlimit rlmt; if (initialized) return; + + getrlimit (RLIMIT_NOFILE, &rlmt); + rlmt.rlim_cur = rlmt.rlim_max; + setrlimit (RLIMIT_NOFILE, &rlmt); checkroot(); ret = system("/sbin/modprobe cpufreq_stats > /dev/null 2>&1"); -- 1.7.7.4