This is a note to let you know that I've just added the patch titled
perf/x86/intel: Support the PEBS event mask
to the 6.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
perf-x86-intel-support-the-pebs-event-mask.patch
and it can be found in the queue-6.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 34d459e35c1ad1e14de2d13bcae9cebe8a72f8cb
Author: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Date: Wed Jun 26 07:35:33 2024 -0700
perf/x86/intel: Support the PEBS event mask
[ Upstream commit a23eb2fc1d818cdac9b31f032842d55483a6a040 ]
The current perf assumes that the counters that support PEBS are
contiguous. But it's not guaranteed with the new leaf 0x23 introduced.
The counters are enumerated with a counter mask. There may be holes in
the counter mask for future platforms or in a virtualization
environment.
Store the PEBS event mask rather than the maximum number of PEBS
counters in the x86 PMU structures.
Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20240626143545.480761-2-kan.liang@xxxxxxxxxxxxxxx
Stable-dep-of: f73cefa3b72e ("perf/x86: Fix smp_processor_id()-in-preemptible warnings")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 101a21fe9c213..2175ca2fdba47 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -4728,7 +4728,7 @@ static void intel_pmu_check_hybrid_pmus(struct x86_hybrid_pmu *pmu)
{
intel_pmu_check_num_counters(&pmu->num_counters, &pmu->num_counters_fixed,
&pmu->intel_ctrl, (1ULL << pmu->num_counters_fixed) - 1);
- pmu->max_pebs_events = min_t(unsigned, MAX_PEBS_EVENTS, pmu->num_counters);
+ pmu->pebs_events_mask = intel_pmu_pebs_mask(GENMASK_ULL(pmu->num_counters - 1, 0));
pmu->unconstrained = (struct event_constraint)
__EVENT_CONSTRAINT(0, (1ULL << pmu->num_counters) - 1,
0, pmu->num_counters, 0, 0);
@@ -6070,7 +6070,7 @@ static __always_inline int intel_pmu_init_hybrid(enum hybrid_pmu_type pmus)
pmu->num_counters = x86_pmu.num_counters;
pmu->num_counters_fixed = x86_pmu.num_counters_fixed;
- pmu->max_pebs_events = min_t(unsigned, MAX_PEBS_EVENTS, pmu->num_counters);
+ pmu->pebs_events_mask = intel_pmu_pebs_mask(GENMASK_ULL(pmu->num_counters - 1, 0));
pmu->unconstrained = (struct event_constraint)
__EVENT_CONSTRAINT(0, (1ULL << pmu->num_counters) - 1,
0, pmu->num_counters, 0, 0);
@@ -6193,7 +6193,7 @@ __init int intel_pmu_init(void)
x86_pmu.events_maskl = ebx.full;
x86_pmu.events_mask_len = eax.split.mask_length;
- x86_pmu.max_pebs_events = min_t(unsigned, MAX_PEBS_EVENTS, x86_pmu.num_counters);
+ x86_pmu.pebs_events_mask = intel_pmu_pebs_mask(GENMASK_ULL(x86_pmu.num_counters - 1, 0));
x86_pmu.pebs_capable = PEBS_COUNTER_MASK;
/*
@@ -6826,7 +6826,7 @@ __init int intel_pmu_init(void)
pmu->num_counters_fixed = x86_pmu.num_counters_fixed;
}
- pmu->max_pebs_events = min_t(unsigned, MAX_PEBS_EVENTS, pmu->num_counters);
+ pmu->pebs_events_mask = intel_pmu_pebs_mask(GENMASK_ULL(pmu->num_counters - 1, 0));
pmu->unconstrained = (struct event_constraint)
__EVENT_CONSTRAINT(0, (1ULL << pmu->num_counters) - 1,
0, pmu->num_counters, 0, 0);
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index 80a4f712217b7..87d3feb9f8fe8 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -1137,7 +1137,7 @@ void intel_pmu_pebs_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sche
static inline void pebs_update_threshold(struct cpu_hw_events *cpuc)
{
struct debug_store *ds = cpuc->ds;
- int max_pebs_events = hybrid(cpuc->pmu, max_pebs_events);
+ int max_pebs_events = intel_pmu_max_num_pebs(cpuc->pmu);
int num_counters_fixed = hybrid(cpuc->pmu, num_counters_fixed);
u64 threshold;
int reserved;
@@ -2161,6 +2161,7 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs, struct perf_sample_d
void *base, *at, *top;
short counts[INTEL_PMC_IDX_FIXED + MAX_FIXED_PEBS_EVENTS] = {};
short error[INTEL_PMC_IDX_FIXED + MAX_FIXED_PEBS_EVENTS] = {};
+ int max_pebs_events = intel_pmu_max_num_pebs(NULL);
int bit, i, size;
u64 mask;
@@ -2172,8 +2173,8 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs, struct perf_sample_d
ds->pebs_index = ds->pebs_buffer_base;
- mask = (1ULL << x86_pmu.max_pebs_events) - 1;
- size = x86_pmu.max_pebs_events;
+ mask = x86_pmu.pebs_events_mask;
+ size = max_pebs_events;
if (x86_pmu.flags & PMU_FL_PEBS_ALL) {
mask |= ((1ULL << x86_pmu.num_counters_fixed) - 1) << INTEL_PMC_IDX_FIXED;
size = INTEL_PMC_IDX_FIXED + x86_pmu.num_counters_fixed;
@@ -2212,8 +2213,9 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs, struct perf_sample_d
pebs_status = p->status = cpuc->pebs_enabled;
bit = find_first_bit((unsigned long *)&pebs_status,
- x86_pmu.max_pebs_events);
- if (bit >= x86_pmu.max_pebs_events)
+ max_pebs_events);
+
+ if (!(x86_pmu.pebs_events_mask & (1 << bit)))
continue;
/*
@@ -2271,7 +2273,6 @@ static void intel_pmu_drain_pebs_icl(struct pt_regs *iregs, struct perf_sample_d
{
short counts[INTEL_PMC_IDX_FIXED + MAX_FIXED_PEBS_EVENTS] = {};
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
- int max_pebs_events = hybrid(cpuc->pmu, max_pebs_events);
int num_counters_fixed = hybrid(cpuc->pmu, num_counters_fixed);
struct debug_store *ds = cpuc->ds;
struct perf_event *event;
@@ -2287,7 +2288,7 @@ static void intel_pmu_drain_pebs_icl(struct pt_regs *iregs, struct perf_sample_d
ds->pebs_index = ds->pebs_buffer_base;
- mask = ((1ULL << max_pebs_events) - 1) |
+ mask = hybrid(cpuc->pmu, pebs_events_mask) |
(((1ULL << num_counters_fixed) - 1) << INTEL_PMC_IDX_FIXED);
size = INTEL_PMC_IDX_FIXED + num_counters_fixed;
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index 72b022a1e16c5..a7ba2868018ca 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -684,7 +684,7 @@ struct x86_hybrid_pmu {
cpumask_t supported_cpus;
union perf_capabilities intel_cap;
u64 intel_ctrl;
- int max_pebs_events;
+ u64 pebs_events_mask;
int num_counters;
int num_counters_fixed;
struct event_constraint unconstrained;
@@ -852,7 +852,7 @@ struct x86_pmu {
pebs_ept :1;
int pebs_record_size;
int pebs_buffer_size;
- int max_pebs_events;
+ u64 pebs_events_mask;
void (*drain_pebs)(struct pt_regs *regs, struct perf_sample_data *data);
struct event_constraint *pebs_constraints;
void (*pebs_aliases)(struct perf_event *event);
@@ -1661,6 +1661,17 @@ static inline int is_ht_workaround_enabled(void)
return !!(x86_pmu.flags & PMU_FL_EXCL_ENABLED);
}
+static inline u64 intel_pmu_pebs_mask(u64 cntr_mask)
+{
+ return MAX_PEBS_EVENTS_MASK & cntr_mask;
+}
+
+static inline int intel_pmu_max_num_pebs(struct pmu *pmu)
+{
+ static_assert(MAX_PEBS_EVENTS == 32);
+ return fls((u32)hybrid(pmu, pebs_events_mask));
+}
+
#else /* CONFIG_CPU_SUP_INTEL */
static inline void reserve_ds_buffers(void)
diff --git a/arch/x86/include/asm/intel_ds.h b/arch/x86/include/asm/intel_ds.h
index 2f9eeb5c3069a..5dbeac48a5b93 100644
--- a/arch/x86/include/asm/intel_ds.h
+++ b/arch/x86/include/asm/intel_ds.h
@@ -9,6 +9,7 @@
/* The maximal number of PEBS events: */
#define MAX_PEBS_EVENTS_FMT4 8
#define MAX_PEBS_EVENTS 32
+#define MAX_PEBS_EVENTS_MASK GENMASK_ULL(MAX_PEBS_EVENTS - 1, 0)
#define MAX_FIXED_PEBS_EVENTS 16
/*
