A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-30 19:51:31 -04:00
Code Issues Projects Releases Packages Wiki Activity

perf/x86/intel: Honour the CPUID for number of fixed counters in hypervisors

Browse source 
perf doesn't seem to honour the number of fixed counters specified by CPUID
leaf 0xa. It always assumes that Intel CPUs have at least 3 fixed counters.

So if some of the fixed counters are masked out by the hypervisor, it still
tries to check/set them.

This patch makes perf behave nicer when the kernel is running under a
hypervisor that doesn't expose all the counters.

This patch contains some ideas from Matt Wilson.

Signed-off-by: Imre Palik <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Andi Kleen <[email protected]>
Cc: Alexander Kozyrev <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Artyom Kuanbekov <[email protected]>
Cc: David Carrillo-Cisneros <[email protected]>
Cc: David Woodhouse <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Matt Wilson <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
This commit is contained in:
Imre Palik 2016-10-21 01:18:59 -07:00 • committed by Ingo Molnar
commit f92b760414
1 changed files with 7 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

10
arch/x86/events/intel/core.c
View file

@ -3607,10 +3607,14 @@ __init int intel_pmu_init(void)
/*
* Quirk: v2 perfmon does not report fixed-purpose events, so
* assume at least 3 events:
* assume at least 3 events, when not running in a hypervisor:
*/
if (version > 1)
x86_pmu.num_counters_fixed = max((int)edx.split.num_counters_fixed, 3);
if (version > 1) {
int assume = 3 * !boot_cpu_has(X86_FEATURE_HYPERVISOR);
x86_pmu.num_counters_fixed =
max((int)edx.split.num_counters_fixed, assume);
}
if (boot_cpu_has(X86_FEATURE_PDCM)) {
u64 capabilities;