From: Stephane Eranian eranian@google.com
[ Upstream commit 0036fb00a756a2f6e360d44e2e3d2200a8afbc9b ]
The RAPL events exposed under /sys/devices/power/events should only reflect what the underlying hardware actually support. This is how it works on Intel RAPL and Intel core/uncore PMUs in general. But on AMD, this was not the case. All possible RAPL events were advertised.
This is what it showed on an AMD Fam17h: $ ls /sys/devices/power/events/ energy-cores energy-gpu energy-pkg energy-psys energy-ram energy-cores.scale energy-gpu.scale energy-pkg.scale energy-psys.scale energy-ram.scale energy-cores.unit energy-gpu.unit energy-pkg.unit energy-psys.unit energy-ram.unit
Yet, on AMD Fam17h, only energy-pkg is supported.
This patch fixes the problem. Given the way perf_msr_probe() works, the amd_rapl_msrs[] table has to have all entries filled out and in particular the group field, otherwise perf_msr_probe() defaults to making the event visible.
With the patch applied, the kernel now only shows was is actually supported:
$ ls /sys/devices/power/events/ energy-pkg energy-pkg.scale energy-pkg.unit
The patch also uses the RAPL_MSR_MASK because only the 32-bits LSB of the RAPL counters are relevant when reading power consumption.
Signed-off-by: Stephane Eranian eranian@google.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Link: https://lkml.kernel.org/r/20220105185659.643355-1-eranian@google.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/events/rapl.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/x86/events/rapl.c b/arch/x86/events/rapl.c index 85feafacc445d..77e3a47af5ad5 100644 --- a/arch/x86/events/rapl.c +++ b/arch/x86/events/rapl.c @@ -536,11 +536,14 @@ static struct perf_msr intel_rapl_spr_msrs[] = { * - perf_msr_probe(PERF_RAPL_MAX) * - want to use same event codes across both architectures */ -static struct perf_msr amd_rapl_msrs[PERF_RAPL_MAX] = { - [PERF_RAPL_PKG] = { MSR_AMD_PKG_ENERGY_STATUS, &rapl_events_pkg_group, test_msr }, +static struct perf_msr amd_rapl_msrs[] = { + [PERF_RAPL_PP0] = { 0, &rapl_events_cores_group, 0, false, 0 }, + [PERF_RAPL_PKG] = { MSR_AMD_PKG_ENERGY_STATUS, &rapl_events_pkg_group, test_msr, false, RAPL_MSR_MASK }, + [PERF_RAPL_RAM] = { 0, &rapl_events_ram_group, 0, false, 0 }, + [PERF_RAPL_PP1] = { 0, &rapl_events_gpu_group, 0, false, 0 }, + [PERF_RAPL_PSYS] = { 0, &rapl_events_psys_group, 0, false, 0 }, };
- static int rapl_cpu_offline(unsigned int cpu) { struct rapl_pmu *pmu = cpu_to_rapl_pmu(cpu);