2022-05-19 11:14:34

by Sandipan Das

[permalink] [raw]
Subject: [PATCH 1/5] perf/x86/amd/uncore: Use dynamic events array

If AMD Performance Monitoring Version 2 (PerfMonV2) is
supported, the number of available counters for a given
uncore PMU may not be fixed across families and models
and has to be determined at runtime.

The per-cpu uncore PMU data currently uses a fixed-sized
array for event information. Make it dynamic based on the
number of available counters.

Signed-off-by: Sandipan Das <[email protected]>
---
arch/x86/events/amd/uncore.c | 38 +++++++++++++++++++++++++++++-------
1 file changed, 31 insertions(+), 7 deletions(-)

diff --git a/arch/x86/events/amd/uncore.c b/arch/x86/events/amd/uncore.c
index 0d04414b97d2..8dfcf93711ab 100644
--- a/arch/x86/events/amd/uncore.c
+++ b/arch/x86/events/amd/uncore.c
@@ -21,7 +21,6 @@
#define NUM_COUNTERS_NB 4
#define NUM_COUNTERS_L2 4
#define NUM_COUNTERS_L3 6
-#define MAX_COUNTERS 6

#define RDPMC_BASE_NB 6
#define RDPMC_BASE_LLC 10
@@ -46,7 +45,7 @@ struct amd_uncore {
u32 msr_base;
cpumask_t *active_mask;
struct pmu *pmu;
- struct perf_event *events[MAX_COUNTERS];
+ struct perf_event **events;
struct hlist_node node;
};

@@ -370,11 +369,19 @@ static struct amd_uncore *amd_uncore_alloc(unsigned int cpu)
cpu_to_node(cpu));
}

+static inline struct perf_event **
+amd_uncore_events_alloc(unsigned int num, unsigned int cpu)
+{
+ return kzalloc_node(sizeof(struct perf_event *) * num, GFP_KERNEL,
+ cpu_to_node(cpu));
+}
+
static int amd_uncore_cpu_up_prepare(unsigned int cpu)
{
- struct amd_uncore *uncore_nb = NULL, *uncore_llc;
+ struct amd_uncore *uncore_nb = NULL, *uncore_llc = NULL;

if (amd_uncore_nb) {
+ *per_cpu_ptr(amd_uncore_nb, cpu) = NULL;
uncore_nb = amd_uncore_alloc(cpu);
if (!uncore_nb)
goto fail;
@@ -384,11 +391,15 @@ static int amd_uncore_cpu_up_prepare(unsigned int cpu)
uncore_nb->msr_base = MSR_F15H_NB_PERF_CTL;
uncore_nb->active_mask = &amd_nb_active_mask;
uncore_nb->pmu = &amd_nb_pmu;
+ uncore_nb->events = amd_uncore_events_alloc(num_counters_nb, cpu);
+ if (!uncore_nb->events)
+ goto fail;
uncore_nb->id = -1;
*per_cpu_ptr(amd_uncore_nb, cpu) = uncore_nb;
}

if (amd_uncore_llc) {
+ *per_cpu_ptr(amd_uncore_llc, cpu) = NULL;
uncore_llc = amd_uncore_alloc(cpu);
if (!uncore_llc)
goto fail;
@@ -398,6 +409,9 @@ static int amd_uncore_cpu_up_prepare(unsigned int cpu)
uncore_llc->msr_base = MSR_F16H_L2I_PERF_CTL;
uncore_llc->active_mask = &amd_llc_active_mask;
uncore_llc->pmu = &amd_llc_pmu;
+ uncore_llc->events = amd_uncore_events_alloc(num_counters_llc, cpu);
+ if (!uncore_llc->events)
+ goto fail;
uncore_llc->id = -1;
*per_cpu_ptr(amd_uncore_llc, cpu) = uncore_llc;
}
@@ -405,9 +419,16 @@ static int amd_uncore_cpu_up_prepare(unsigned int cpu)
return 0;

fail:
- if (amd_uncore_nb)
- *per_cpu_ptr(amd_uncore_nb, cpu) = NULL;
- kfree(uncore_nb);
+ if (uncore_nb) {
+ kfree(uncore_nb->events);
+ kfree(uncore_nb);
+ }
+
+ if (uncore_llc) {
+ kfree(uncore_llc->events);
+ kfree(uncore_llc);
+ }
+
return -ENOMEM;
}

@@ -540,8 +561,11 @@ static void uncore_dead(unsigned int cpu, struct amd_uncore * __percpu *uncores)
if (cpu == uncore->cpu)
cpumask_clear_cpu(cpu, uncore->active_mask);

- if (!--uncore->refcnt)
+ if (!--uncore->refcnt) {
+ kfree(uncore->events);
kfree(uncore);
+ }
+
*per_cpu_ptr(uncores, cpu) = NULL;
}

--
2.34.1