[PATCH V3 10/25] perf/x86: Hybrid PMU support for extra_regs

From: kan . liang
Date: Fri Mar 26 2021 - 15:09:50 EST


From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>

Different hybrid PMU may have different extra registers, e.g. Core PMU
may have offcore registers, frontend register and ldlat register. Atom
core may only have offcore registers and ldlat register. Each hybrid PMU
should use its own extra_regs.

An Intel Hybrid system should always have extra registers.
Unconditionally allocate shared_regs for Intel Hybrid system.

Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
---
arch/x86/events/core.c | 5 +++--
arch/x86/events/intel/core.c | 15 +++++++++------
arch/x86/events/perf_event.h | 1 +
3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index b866867..b79a506 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -153,15 +153,16 @@ u64 x86_perf_event_update(struct perf_event *event)
*/
static int x86_pmu_extra_regs(u64 config, struct perf_event *event)
{
+ struct extra_reg *extra_regs = hybrid(event->pmu, extra_regs);
struct hw_perf_event_extra *reg;
struct extra_reg *er;

reg = &event->hw.extra_reg;

- if (!x86_pmu.extra_regs)
+ if (!extra_regs)
return 0;

- for (er = x86_pmu.extra_regs; er->msr; er++) {
+ for (er = extra_regs; er->msr; er++) {
if (er->event != (config & er->config_mask))
continue;
if (event->attr.config1 & ~er->valid_mask)
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index d304ba3..b5b7694 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -2966,8 +2966,10 @@ intel_vlbr_constraints(struct perf_event *event)
return NULL;
}

-static int intel_alt_er(int idx, u64 config)
+static int intel_alt_er(struct cpu_hw_events *cpuc,
+ int idx, u64 config)
{
+ struct extra_reg *extra_regs = hybrid(cpuc->pmu, extra_regs);
int alt_idx = idx;

if (!(x86_pmu.flags & PMU_FL_HAS_RSP_1))
@@ -2979,7 +2981,7 @@ static int intel_alt_er(int idx, u64 config)
if (idx == EXTRA_REG_RSP_1)
alt_idx = EXTRA_REG_RSP_0;

- if (config & ~x86_pmu.extra_regs[alt_idx].valid_mask)
+ if (config & ~extra_regs[alt_idx].valid_mask)
return idx;

return alt_idx;
@@ -2987,15 +2989,16 @@ static int intel_alt_er(int idx, u64 config)

static void intel_fixup_er(struct perf_event *event, int idx)
{
+ struct extra_reg *extra_regs = hybrid(event->pmu, extra_regs);
event->hw.extra_reg.idx = idx;

if (idx == EXTRA_REG_RSP_0) {
event->hw.config &= ~INTEL_ARCH_EVENT_MASK;
- event->hw.config |= x86_pmu.extra_regs[EXTRA_REG_RSP_0].event;
+ event->hw.config |= extra_regs[EXTRA_REG_RSP_0].event;
event->hw.extra_reg.reg = MSR_OFFCORE_RSP_0;
} else if (idx == EXTRA_REG_RSP_1) {
event->hw.config &= ~INTEL_ARCH_EVENT_MASK;
- event->hw.config |= x86_pmu.extra_regs[EXTRA_REG_RSP_1].event;
+ event->hw.config |= extra_regs[EXTRA_REG_RSP_1].event;
event->hw.extra_reg.reg = MSR_OFFCORE_RSP_1;
}
}
@@ -3071,7 +3074,7 @@ __intel_shared_reg_get_constraints(struct cpu_hw_events *cpuc,
*/
c = NULL;
} else {
- idx = intel_alt_er(idx, reg->config);
+ idx = intel_alt_er(cpuc, idx, reg->config);
if (idx != reg->idx) {
raw_spin_unlock_irqrestore(&era->lock, flags);
goto again;
@@ -4161,7 +4164,7 @@ int intel_cpuc_prepare(struct cpu_hw_events *cpuc, int cpu)
{
cpuc->pebs_record_size = x86_pmu.pebs_record_size;

- if (x86_pmu.extra_regs || x86_pmu.lbr_sel_map) {
+ if (is_hybrid() || x86_pmu.extra_regs || x86_pmu.lbr_sel_map) {
cpuc->shared_regs = allocate_shared_regs(cpu);
if (!cpuc->shared_regs)
goto err;
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index 53e8a0f..bd53390 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -651,6 +651,7 @@ struct x86_hybrid_pmu {
[PERF_COUNT_HW_CACHE_RESULT_MAX];
struct event_constraint *event_constraints;
struct event_constraint *pebs_constraints;
+ struct extra_reg *extra_regs;
};

static __always_inline bool is_hybrid(void)
--
2.7.4