[Patch v3 7/7] perf/x86: Print PMU counters bitmap in x86_pmu_show_pmu_cap()

From: Dapeng Mi
Date: Tue Aug 19 2025 - 22:36:00 EST


Along with the introduction Perfmon v6, pmu counters could be
incontinuous, like fixed counters on CWF, only fixed counters 0-3 and
5-7 are supported, there is no fixed counter 4 on CWF. To accommodate
this change, archPerfmonExt CPUID (0x23) leaves are introduced to
enumerate the true-view of counters bitmap.

Current perf code already supports archPerfmonExt CPUID and uses
counters-bitmap to enumerate HW really supported counters, but
x86_pmu_show_pmu_cap() still only dumps the absolute counter number
instead of true-view bitmap, it's out-dated and may mislead readers.

So dump counters true-view bitmap in x86_pmu_show_pmu_cap() and
opportunistically change the dump sequence and words.

Signed-off-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
---
arch/x86/events/core.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 7610f26dfbd9..745caa6c15a3 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2069,13 +2069,15 @@ static void _x86_pmu_read(struct perf_event *event)

void x86_pmu_show_pmu_cap(struct pmu *pmu)
{
- pr_info("... version: %d\n", x86_pmu.version);
- pr_info("... bit width: %d\n", x86_pmu.cntval_bits);
- pr_info("... generic registers: %d\n", x86_pmu_num_counters(pmu));
- pr_info("... value mask: %016Lx\n", x86_pmu.cntval_mask);
- pr_info("... max period: %016Lx\n", x86_pmu.max_period);
- pr_info("... fixed-purpose events: %d\n", x86_pmu_num_counters_fixed(pmu));
- pr_info("... event mask: %016Lx\n", hybrid(pmu, intel_ctrl));
+ pr_info("... version: %d\n", x86_pmu.version);
+ pr_info("... bit width: %d\n", x86_pmu.cntval_bits);
+ pr_info("... generic counters: %d\n", x86_pmu_num_counters(pmu));
+ pr_info("... generic bitmap: %016llx\n", hybrid(pmu, cntr_mask64));
+ pr_info("... fixed-purpose counters: %d\n", x86_pmu_num_counters_fixed(pmu));
+ pr_info("... fixed-purpose bitmap: %016llx\n", hybrid(pmu, fixed_cntr_mask64));
+ pr_info("... value mask: %016llx\n", x86_pmu.cntval_mask);
+ pr_info("... max period: %016llx\n", x86_pmu.max_period);
+ pr_info("... global_ctrl mask: %016llx\n", hybrid(pmu, intel_ctrl));
}

static int __init init_hw_perf_events(void)
--
2.34.1