perf/x86: Hybrid PMU support for counters
authorKan Liang <kan.liang@linux.intel.com>
Mon, 12 Apr 2021 14:30:46 +0000 (07:30 -0700)
committerPeter Zijlstra <peterz@infradead.org>
Mon, 19 Apr 2021 18:03:25 +0000 (20:03 +0200)
The number of GP and fixed counters are different among hybrid PMUs.
Each hybrid PMU should use its own counter related information.

When handling a certain hybrid PMU, apply the number of counters from
the corresponding hybrid PMU.

When reserving the counters in the initialization of a new event,
reserve all possible counters.

The number of counter recored in the global x86_pmu is for the
architecture counters which are available for all hybrid PMUs. KVM
doesn't support the hybrid PMU yet. Return the number of the
architecture counters for now.

For the functions only available for the old platforms, e.g.,
intel_pmu_drain_pebs_nhm(), nothing is changed.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Link: https://lkml.kernel.org/r/1618237865-33448-7-git-send-email-kan.liang@linux.intel.com
arch/x86/events/core.c
arch/x86/events/intel/core.c
arch/x86/events/intel/ds.c
arch/x86/events/perf_event.h

index 7d3c19ec45fe2e322e6a614088aaf9e51629994f..1aeb31cb4ee5e9cfa1b73cae38519b2f76d96ea9 100644 (file)
@@ -185,16 +185,29 @@ static DEFINE_MUTEX(pmc_reserve_mutex);
 
 #ifdef CONFIG_X86_LOCAL_APIC
 
+static inline int get_possible_num_counters(void)
+{
+       int i, num_counters = x86_pmu.num_counters;
+
+       if (!is_hybrid())
+               return num_counters;
+
+       for (i = 0; i < x86_pmu.num_hybrid_pmus; i++)
+               num_counters = max_t(int, num_counters, x86_pmu.hybrid_pmu[i].num_counters);
+
+       return num_counters;
+}
+
 static bool reserve_pmc_hardware(void)
 {
-       int i;
+       int i, num_counters = get_possible_num_counters();
 
-       for (i = 0; i < x86_pmu.num_counters; i++) {
+       for (i = 0; i < num_counters; i++) {
                if (!reserve_perfctr_nmi(x86_pmu_event_addr(i)))
                        goto perfctr_fail;
        }
 
-       for (i = 0; i < x86_pmu.num_counters; i++) {
+       for (i = 0; i < num_counters; i++) {
                if (!reserve_evntsel_nmi(x86_pmu_config_addr(i)))
                        goto eventsel_fail;
        }
@@ -205,7 +218,7 @@ eventsel_fail:
        for (i--; i >= 0; i--)
                release_evntsel_nmi(x86_pmu_config_addr(i));
 
-       i = x86_pmu.num_counters;
+       i = num_counters;
 
 perfctr_fail:
        for (i--; i >= 0; i--)
@@ -216,9 +229,9 @@ perfctr_fail:
 
 static void release_pmc_hardware(void)
 {
-       int i;
+       int i, num_counters = get_possible_num_counters();
 
-       for (i = 0; i < x86_pmu.num_counters; i++) {
+       for (i = 0; i < num_counters; i++) {
                release_perfctr_nmi(x86_pmu_event_addr(i));
                release_evntsel_nmi(x86_pmu_config_addr(i));
        }
@@ -946,6 +959,7 @@ EXPORT_SYMBOL_GPL(perf_assign_events);
 
 int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
 {
+       int num_counters = hybrid(cpuc->pmu, num_counters);
        struct event_constraint *c;
        struct perf_event *e;
        int n0, i, wmin, wmax, unsched = 0;
@@ -1021,7 +1035,7 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
 
        /* slow path */
        if (i != n) {
-               int gpmax = x86_pmu.num_counters;
+               int gpmax = num_counters;
 
                /*
                 * Do not allow scheduling of more than half the available
@@ -1042,7 +1056,7 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
                 * the extra Merge events needed by large increment events.
                 */
                if (x86_pmu.flags & PMU_FL_PAIR) {
-                       gpmax = x86_pmu.num_counters - cpuc->n_pair;
+                       gpmax = num_counters - cpuc->n_pair;
                        WARN_ON(gpmax <= 0);
                }
 
@@ -1129,10 +1143,12 @@ static int collect_event(struct cpu_hw_events *cpuc, struct perf_event *event,
  */
 static int collect_events(struct cpu_hw_events *cpuc, struct perf_event *leader, bool dogrp)
 {
+       int num_counters = hybrid(cpuc->pmu, num_counters);
+       int num_counters_fixed = hybrid(cpuc->pmu, num_counters_fixed);
        struct perf_event *event;
        int n, max_count;
 
-       max_count = x86_pmu.num_counters + x86_pmu.num_counters_fixed;
+       max_count = num_counters + num_counters_fixed;
 
        /* current number of events already accepted */
        n = cpuc->n_events;
@@ -1499,18 +1515,18 @@ void perf_event_print_debug(void)
 {
        u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed;
        u64 pebs, debugctl;
-       struct cpu_hw_events *cpuc;
+       int cpu = smp_processor_id();
+       struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
+       int num_counters = hybrid(cpuc->pmu, num_counters);
+       int num_counters_fixed = hybrid(cpuc->pmu, num_counters_fixed);
        unsigned long flags;
-       int cpu, idx;
+       int idx;
 
-       if (!x86_pmu.num_counters)
+       if (!num_counters)
                return;
 
        local_irq_save(flags);
 
-       cpu = smp_processor_id();
-       cpuc = &per_cpu(cpu_hw_events, cpu);
-
        if (x86_pmu.version >= 2) {
                rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, ctrl);
                rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status);
@@ -1533,7 +1549,7 @@ void perf_event_print_debug(void)
        }
        pr_info("CPU#%d: active:     %016llx\n", cpu, *(u64 *)cpuc->active_mask);
 
-       for (idx = 0; idx < x86_pmu.num_counters; idx++) {
+       for (idx = 0; idx < num_counters; idx++) {
                rdmsrl(x86_pmu_config_addr(idx), pmc_ctrl);
                rdmsrl(x86_pmu_event_addr(idx), pmc_count);
 
@@ -1546,7 +1562,7 @@ void perf_event_print_debug(void)
                pr_info("CPU#%d:   gen-PMC%d left:  %016llx\n",
                        cpu, idx, prev_left);
        }
-       for (idx = 0; idx < x86_pmu.num_counters_fixed; idx++) {
+       for (idx = 0; idx < num_counters_fixed; idx++) {
                if (fixed_counter_disabled(idx, cpuc->pmu))
                        continue;
                rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR0 + idx, pmc_count);
@@ -2781,6 +2797,11 @@ unsigned long perf_misc_flags(struct pt_regs *regs)
 void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap)
 {
        cap->version            = x86_pmu.version;
+       /*
+        * KVM doesn't support the hybrid PMU yet.
+        * Return the common value in global x86_pmu,
+        * which available for all cores.
+        */
        cap->num_counters_gp    = x86_pmu.num_counters;
        cap->num_counters_fixed = x86_pmu.num_counters_fixed;
        cap->bit_width_gp       = x86_pmu.cntval_bits;
index 2d56055d7376b5faaa14cd7788894cb7ac0da496..3ea0126e6db6c40aafeaba7265cbf39662fab511 100644 (file)
@@ -2711,21 +2711,23 @@ static void intel_pmu_reset(void)
 {
        struct debug_store *ds = __this_cpu_read(cpu_hw_events.ds);
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+       int num_counters_fixed = hybrid(cpuc->pmu, num_counters_fixed);
+       int num_counters = hybrid(cpuc->pmu, num_counters);
        unsigned long flags;
        int idx;
 
-       if (!x86_pmu.num_counters)
+       if (!num_counters)
                return;
 
        local_irq_save(flags);
 
        pr_info("clearing PMU state on CPU#%d\n", smp_processor_id());
 
-       for (idx = 0; idx < x86_pmu.num_counters; idx++) {
+       for (idx = 0; idx < num_counters; idx++) {
                wrmsrl_safe(x86_pmu_config_addr(idx), 0ull);
                wrmsrl_safe(x86_pmu_event_addr(idx),  0ull);
        }
-       for (idx = 0; idx < x86_pmu.num_counters_fixed; idx++) {
+       for (idx = 0; idx < num_counters_fixed; idx++) {
                if (fixed_counter_disabled(idx, cpuc->pmu))
                        continue;
                wrmsrl_safe(MSR_ARCH_PERFMON_FIXED_CTR0 + idx, 0ull);
index 9328aa1b2bbf90e5499207d8a22ea1756b0a47a1..312bf3b673a101af43f436187fca53d6d3129f54 100644 (file)
@@ -1007,6 +1007,8 @@ void intel_pmu_pebs_sched_task(struct perf_event_context *ctx, bool sched_in)
 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 num_counters_fixed = hybrid(cpuc->pmu, num_counters_fixed);
        u64 threshold;
        int reserved;
 
@@ -1014,9 +1016,9 @@ static inline void pebs_update_threshold(struct cpu_hw_events *cpuc)
                return;
 
        if (x86_pmu.flags & PMU_FL_PEBS_ALL)
-               reserved = x86_pmu.max_pebs_events + x86_pmu.num_counters_fixed;
+               reserved = max_pebs_events + num_counters_fixed;
        else
-               reserved = x86_pmu.max_pebs_events;
+               reserved = max_pebs_events;
 
        if (cpuc->n_pebs == cpuc->n_large_pebs) {
                threshold = ds->pebs_absolute_maximum -
@@ -2072,6 +2074,8 @@ 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;
        void *base, *at, *top;
@@ -2086,9 +2090,9 @@ static void intel_pmu_drain_pebs_icl(struct pt_regs *iregs, struct perf_sample_d
 
        ds->pebs_index = ds->pebs_buffer_base;
 
-       mask = ((1ULL << x86_pmu.max_pebs_events) - 1) |
-              (((1ULL << x86_pmu.num_counters_fixed) - 1) << INTEL_PMC_IDX_FIXED);
-       size = INTEL_PMC_IDX_FIXED + x86_pmu.num_counters_fixed;
+       mask = ((1ULL << max_pebs_events) - 1) |
+              (((1ULL << num_counters_fixed) - 1) << INTEL_PMC_IDX_FIXED);
+       size = INTEL_PMC_IDX_FIXED + num_counters_fixed;
 
        if (unlikely(base >= top)) {
                intel_pmu_pebs_event_update_no_drain(cpuc, size);
index 557c6746bc400ba89d655ef3b8f712998bbbd27d..0539ad4157502877020395a7043a4f1579b671e9 100644 (file)
@@ -635,6 +635,9 @@ struct x86_hybrid_pmu {
        struct pmu                      pmu;
        union perf_capabilities         intel_cap;
        u64                             intel_ctrl;
+       int                             max_pebs_events;
+       int                             num_counters;
+       int                             num_counters_fixed;
 };
 
 static __always_inline struct x86_hybrid_pmu *hybrid_pmu(struct pmu *pmu)
@@ -850,6 +853,7 @@ struct x86_pmu {
         * are available for all PMUs. The hybrid_pmu only includes the
         * unique capabilities.
         */
+       int                             num_hybrid_pmus;
        struct x86_hybrid_pmu           *hybrid_pmu;
 };