turbostat does not function properly on systems that support CPU0 hotplug.
When running turbostat on these systems the following error is seen.
[root@intel-chiefriver-04 ~]# turbostat ls
turbostat: no /dev/cpu/0/msr
Try "# modprobe msr": No such file or directory
This happens because base_cpu is set to 0 in the turbostat code and calls
to check_dev_msr() will fail if CPU0 has been removed.
This patchset adds functionality to set the value of base_cpu to the lowest
found cpu on the system. This patch moves setup_all_buffers() to the
beginning of the turbostat_init() so that set_base_cpu() can take advantage
of topo.max_cpu_num which is set in setup_all_buffers().
After this change, on a system that has CPU0 removed,
[root@prarit ~]# ./turbostat -d -d ls
turbostat version 4.5 2 Apr, 2015 - Len Brown <l...@kernel.org>
num_cpus 7 max_cpu_num 7
cpu0 NOT PRESENT
cpu 1 pkg 0 core 0
cpu 2 pkg 0 core 1
cpu 3 pkg 0 core 1
cpu 4 pkg 0 core 2
cpu 5 pkg 0 core 2
cpu 6 pkg 0 core 3
cpu 7 pkg 0 core 3
<snip>
anaconda-ks.cfg README turbostat
Core CPU Avg_MHz %Busy Bzy_MHz TSC_MHz SMI CPU%c1 CPU%c3
CPU%c6 CPU%c7 CoreTmp PkgTmp Pkg%pc2 Pkg%pc3 Pkg%pc6 Pkg%pc7 PkgWatt CorWatt
GFXWatt
- - 492 14.20 3462 2634 0 18.90 0.00
0.00 68.63 27 27 0.00 0.00 0.00 0.00 17.65 12.69
0.00
0 1 353 9.95 3552 2645 0 9.68 0.00
0.00 80.37 27 27 0.00 0.00 0.00 0.00 17.65 12.69
0.00
1 2 217 7.70 2814 2614 0 64.63 0.00
0.00 27.68 26
1 3 2006 57.20 3507 2660 0 15.61
2 4 120 3.37 3570 2649 0 10.95 0.00
0.00 85.69 25
2 5 155 4.22 3679 2631 0 9.48
3 6 296 8.38 3530 2620 0 11.07 0.00
0.00 80.55 17
3 7 296 8.15 3630 2617 0 11.22
0.001160 sec
I have additionally tested various other hotplug configurations to make sure
that turbostat behaves correctly in those situations as well.
[v2]: use sched_getcpu() to get current cpu
Signed-off-by: Prarit Bhargava <pra...@redhat.com>
---
tools/power/x86/turbostat/turbostat.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/tools/power/x86/turbostat/turbostat.c
b/tools/power/x86/turbostat/turbostat.c
index 8c2e761..8e4ce9f 100644
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -91,7 +91,7 @@ unsigned int do_gfx_perf_limit_reasons;
unsigned int do_ring_perf_limit_reasons;
unsigned int crystal_hz;
unsigned long long tsc_hz;
-int base_cpu = 0;
+int base_cpu = -1;
#define RAPL_PKG (1 << 0)
/* 0x610 MSR_PKG_POWER_LIMIT */
@@ -2790,13 +2790,24 @@ void setup_all_buffers(void)
for_all_proc_cpus(initialize_counters);
}
+void set_base_cpu(void)
+{
+ base_cpu = sched_getcpu();
+ if (base_cpu < 0)
+ err(-ENODEV, "No valid cpus found");
+
+ if (debug > 1)
+ fprintf(stderr, "base_cpu = %d\n", base_cpu);
+}
+
void turbostat_init()
{
+ setup_all_buffers();
+ set_base_cpu();
check_dev_msr();
check_permissions();
process_cpuid();
- setup_all_buffers();
if (debug)
for_all_cpus(print_epb, ODD_COUNTERS);
--
1.7.9.3
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