diff options
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event.c | 78 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event_intel.c | 260 | ||||
| -rw-r--r-- | include/linux/perf_event.h | 14 |
3 files changed, 200 insertions, 152 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 5b86ec51534c..019fda7489e7 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -45,6 +45,29 @@ do { \ #endif /* + * | NHM/WSM | SNB | + * register ------------------------------- + * | HT | no HT | HT | no HT | + *----------------------------------------- + * offcore | core | core | cpu | core | + * lbr_sel | core | core | cpu | core | + * ld_lat | cpu | core | cpu | core | + *----------------------------------------- + * + * Given that there is a small number of shared regs, + * we can pre-allocate their slot in the per-cpu + * per-core reg tables. + */ +enum extra_reg_type { + EXTRA_REG_NONE = -1, /* not used */ + + EXTRA_REG_RSP_0 = 0, /* offcore_response_0 */ + EXTRA_REG_RSP_1 = 1, /* offcore_response_1 */ + + EXTRA_REG_MAX /* number of entries needed */ +}; + +/* * best effort, GUP based copy_from_user() that assumes IRQ or NMI context */ static unsigned long @@ -132,11 +155,10 @@ struct cpu_hw_events { struct perf_branch_entry lbr_entries[MAX_LBR_ENTRIES]; /* - * Intel percore register state. - * Coordinate shared resources between HT threads. + * manage shared (per-core, per-cpu) registers + * used on Intel NHM/WSM/SNB */ - int percore_used; /* Used by this CPU? */ - struct intel_percore *per_core; + struct intel_shared_regs *shared_regs; /* * AMD specific bits @@ -187,26 +209,45 @@ struct cpu_hw_events { for ((e) = (c); (e)->weight; (e)++) /* + * Per register state. + */ +struct er_account { + raw_spinlock_t lock; /* per-core: protect structure */ + u64 config; /* extra MSR config */ + u64 reg; /* extra MSR number */ + atomic_t ref; /* reference count */ +}; + +/* * Extra registers for specific events. + * * Some events need large masks and require external MSRs. - * Define a mapping to these extra registers. + * Those extra MSRs end up being shared for all events on + * a PMU and sometimes between PMU of sibling HT threads. + * In either case, the kernel needs to handle conflicting + * accesses to those extra, shared, regs. The data structure + * to manage those registers is stored in cpu_hw_event. */ struct extra_reg { unsigned int event; unsigned int msr; u64 config_mask; u64 valid_mask; + int idx; /* per_xxx->regs[] reg index */ }; -#define EVENT_EXTRA_REG(e, ms, m, vm) { \ +#define EVENT_EXTRA_REG(e, ms, m, vm, i) { \ .event = (e), \ .msr = (ms), \ .config_mask = (m), \ .valid_mask = (vm), \ + .idx = EXTRA_REG_##i \ } -#define INTEL_EVENT_EXTRA_REG(event, msr, vm) \ - EVENT_EXTRA_REG(event, msr, ARCH_PERFMON_EVENTSEL_EVENT, vm) -#define EVENT_EXTRA_END EVENT_EXTRA_REG(0, 0, 0, 0) + +#define INTEL_EVENT_EXTRA_REG(event, msr, vm, idx) \ + EVENT_EXTRA_REG(event, msr, ARCH_PERFMON_EVENTSEL_EVENT, vm, idx) + +#define EVENT_EXTRA_END EVENT_EXTRA_REG(0, 0, 0, 0, RSP_0) union perf_capabilities { struct { @@ -253,7 +294,6 @@ struct x86_pmu { void (*put_event_constraints)(struct cpu_hw_events *cpuc, struct perf_event *event); struct event_constraint *event_constraints; - struct event_constraint *percore_constraints; void (*quirks)(void); int perfctr_second_write; @@ -400,10 +440,10 @@ static inline unsigned int x86_pmu_event_addr(int index) */ static int x86_pmu_extra_regs(u64 config, struct perf_event *event) { + struct hw_perf_event_extra *reg; struct extra_reg *er; - event->hw.extra_reg = 0; - event->hw.extra_config = 0; + reg = &event->hw.extra_reg; if (!x86_pmu.extra_regs) return 0; @@ -413,8 +453,10 @@ static int x86_pmu_extra_regs(u64 config, struct perf_event *event) continue; if (event->attr.config1 & ~er->valid_mask) return -EINVAL; - event->hw.extra_reg = er->msr; - event->hw.extra_config = event->attr.config1; + + reg->idx = er->idx; + reg->config = event->attr.config1; + reg->reg = er->msr; break; } return 0; @@ -713,6 +755,9 @@ static int __x86_pmu_event_init(struct perf_event *event) event->hw.last_cpu = -1; event->hw.last_tag = ~0ULL; + /* mark unused */ + event->hw.extra_reg.idx = EXTRA_REG_NONE; + return x86_pmu.hw_config(event); } @@ -754,8 +799,8 @@ static void x86_pmu_disable(struct pmu *pmu) static inline void __x86_pmu_enable_event(struct hw_perf_event *hwc, u64 enable_mask) { - if (hwc->extra_reg) - wrmsrl(hwc->extra_reg, hwc->extra_config); + if (hwc->extra_reg.reg) + wrmsrl(hwc->extra_reg.reg, hwc->extra_reg.config); wrmsrl(hwc->config_base, hwc->config | enable_mask); } @@ -1692,7 +1737,6 @@ static int validate_group(struct perf_event *event) fake_cpuc = kmalloc(sizeof(*fake_cpuc), GFP_KERNEL | __GFP_ZERO); if (!fake_cpuc) goto out; - /* * the event is not yet connected with its * siblings therefore we must first collect diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index d38b0020f775..6ad95baff856 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -1,25 +1,15 @@ #ifdef CONFIG_CPU_SUP_INTEL -#define MAX_EXTRA_REGS 2 - -/* - * Per register state. - */ -struct er_account { - int ref; /* reference count */ - unsigned int extra_reg; /* extra MSR number */ - u64 extra_config; /* extra MSR config */ -}; - /* - * Per core state - * This used to coordinate shared registers for HT threads. + * Per core/cpu state + * + * Used to coordinate shared registers between HT threads or + * among events on a single PMU. */ -struct intel_percore { - raw_spinlock_t lock; /* protect structure */ - struct er_account regs[MAX_EXTRA_REGS]; - int refcnt; /* number of threads */ - unsigned core_id; +struct intel_shared_regs { + struct er_account regs[EXTRA_REG_MAX]; + int refcnt; /* per-core: #HT threads */ + unsigned core_id; /* per-core: core id */ }; /* @@ -88,16 +78,10 @@ static struct event_constraint intel_nehalem_event_constraints[] __read_mostly = static struct extra_reg intel_nehalem_extra_regs[] __read_mostly = { - INTEL_EVENT_EXTRA_REG(0xb7, MSR_OFFCORE_RSP_0, 0xffff), + INTEL_EVENT_EXTRA_REG(0xb7, MSR_OFFCORE_RSP_0, 0xffff, RSP_0), EVENT_EXTRA_END }; -static struct event_constraint intel_nehalem_percore_constraints[] __read_mostly = -{ - INTEL_EVENT_CONSTRAINT(0xb7, 0), - EVENT_CONSTRAINT_END -}; - static struct event_constraint intel_westmere_event_constraints[] __read_mostly = { FIXED_EVENT_CONSTRAINT(0x00c0, 0), /* INST_RETIRED.ANY */ @@ -125,18 +109,11 @@ static struct event_constraint intel_snb_event_constraints[] __read_mostly = static struct extra_reg intel_westmere_extra_regs[] __read_mostly = { - INTEL_EVENT_EXTRA_REG(0xb7, MSR_OFFCORE_RSP_0, 0xffff), - INTEL_EVENT_EXTRA_REG(0xbb, MSR_OFFCORE_RSP_1, 0xffff), + INTEL_EVENT_EXTRA_REG(0xb7, MSR_OFFCORE_RSP_0, 0xffff, RSP_0), + INTEL_EVENT_EXTRA_REG(0xbb, MSR_OFFCORE_RSP_1, 0xffff, RSP_1), EVENT_EXTRA_END }; -static struct event_constraint intel_westmere_percore_constraints[] __read_mostly = -{ - INTEL_EVENT_CONSTRAINT(0xb7, 0), - INTEL_EVENT_CONSTRAINT(0xbb, 0), - EVENT_CONSTRAINT_END -}; - static struct event_constraint intel_gen_event_constraints[] __read_mostly = { FIXED_EVENT_CONSTRAINT(0x00c0, 0), /* INST_RETIRED.ANY */ @@ -1037,65 +1014,89 @@ intel_bts_constraints(struct perf_event *event) return NULL; } +/* + * manage allocation of shared extra msr for certain events + * + * sharing can be: + * per-cpu: to be shared between the various events on a single PMU + * per-core: per-cpu + shared by HT threads + */ static struct event_constraint * -intel_percore_constraints(struct cpu_hw_events *cpuc, struct perf_event *event) +__intel_shared_reg_get_constraints(struct cpu_hw_events *cpuc, + struct hw_perf_event_extra *reg) { - struct hw_perf_event *hwc = &event->hw; - unsigned int e = hwc->config & ARCH_PERFMON_EVENTSEL_EVENT; - struct event_constraint *c; - struct intel_percore *pc; + struct event_constraint *c = &emptyconstraint; struct er_account *era; - int i; - int free_slot; - int found; - if (!x86_pmu.percore_constraints || hwc->extra_alloc) - return NULL; + /* already allocated shared msr */ + if (reg->alloc || !cpuc->shared_regs) + return &unconstrained; - for (c = x86_pmu.percore_constraints; c->cmask; c++) { - if (e != c->code) - continue; + era = &cpuc->shared_regs->regs[reg->idx]; + + raw_spin_lock(&era->lock); + + if (!atomic_read(&era->ref) || era->config == reg->config) { + + /* lock in msr value */ + era->config = reg->config; + era->reg = reg->reg; + + /* one more user */ + atomic_inc(&era->ref); + + /* no need to reallocate during incremental event scheduling */ + reg->alloc = 1; /* - * Allocate resource per core. + * All events using extra_reg are unconstrained. + * Avoids calling x86_get_event_constraints() + * + * Must revisit if extra_reg controlling events + * ever have constraints. Worst case we go through + * the regular event constraint table. */ - pc = cpuc->per_core; - if (!pc) - break; - c = &emptyconstraint; - raw_spin_lock(&pc->lock); - free_slot = -1; - found = 0; - for (i = 0; i < MAX_EXTRA_REGS; i++) { - era = &pc->regs[i]; - if (era->ref > 0 && hwc->extra_reg == era->extra_reg) { - /* Allow sharing same config */ - if (hwc->extra_config == era->extra_config) { - era->ref++; - cpuc->percore_used = 1; - hwc->extra_alloc = 1; - c = NULL; - } - /* else conflict */ - found = 1; - break; - } else if (era->ref == 0 && free_slot == -1) - free_slot = i; - } - if (!found && free_slot != -1) { - era = &pc->regs[free_slot]; - era->ref = 1; - era->extra_reg = hwc->extra_reg; - era->extra_config = hwc->extra_config; - cpuc->percore_used = 1; - hwc->extra_alloc = 1; - c = NULL; - } - raw_spin_unlock(&pc->lock); - return c; + c = &unconstrained; } + raw_spin_unlock(&era->lock); - return NULL; + return c; +} + +static void +__intel_shared_reg_put_constraints(struct cpu_hw_events *cpuc, + struct hw_perf_event_extra *reg) +{ + struct er_account *era; + + /* + * only put constraint if extra reg was actually + * allocated. Also takes care of event which do + * not use an extra shared reg + */ + if (!reg->alloc) + return; + + era = &cpuc->shared_regs->regs[reg->idx]; + + /* one fewer user */ + atomic_dec(&era->ref); + + /* allocate again next time */ + reg->alloc = 0; +} + +static struct event_constraint * +intel_shared_regs_constraints(struct cpu_hw_events *cpuc, + struct perf_event *event) +{ + struct event_constraint *c = NULL; + struct hw_perf_event_extra *xreg; + + xreg = &event->hw.extra_reg; + if (xreg->idx != EXTRA_REG_NONE) + c = __intel_shared_reg_get_constraints(cpuc, xreg); + return c; } static struct event_constraint * @@ -1111,49 +1112,28 @@ intel_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event if (c) return c; - c = intel_percore_constraints(cpuc, event); + c = intel_shared_regs_constraints(cpuc, event); if (c) return c; return x86_get_event_constraints(cpuc, event); } -static void intel_put_event_constraints(struct cpu_hw_events *cpuc, +static void +intel_put_shared_regs_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event) { - struct extra_reg *er; - struct intel_percore *pc; - struct er_account *era; - struct hw_perf_event *hwc = &event->hw; - int i, allref; - - if (!cpuc->percore_used) - return; + struct hw_perf_event_extra *reg; - for (er = x86_pmu.extra_regs; er->msr; er++) { - if (er->event != (hwc->config & er->config_mask)) - continue; + reg = &event->hw.extra_reg; + if (reg->idx != EXTRA_REG_NONE) + __intel_shared_reg_put_constraints(cpuc, reg); +} - pc = cpuc->per_core; - raw_spin_lock(&pc->lock); - for (i = 0; i < MAX_EXTRA_REGS; i++) { - era = &pc->regs[i]; - if (era->ref > 0 && - era->extra_config == hwc->extra_config && - era->extra_reg == er->msr) { - era->ref--; - hwc->extra_alloc = 0; - break; - } - } - allref = 0; - for (i = 0; i < MAX_EXTRA_REGS; i++) - allref += pc->regs[i].ref; - if (allref == 0) - cpuc->percore_used = 0; - raw_spin_unlock(&pc->lock); - break; - } +static void intel_put_event_constraints(struct cpu_hw_events *cpuc, + struct perf_event *event) +{ + intel_put_shared_regs_event_constraints(cpuc, event); } static int intel_pmu_hw_config(struct perf_event *event) @@ -1231,20 +1211,36 @@ static __initconst const struct x86_pmu core_pmu = { .event_constraints = intel_core_event_constraints, }; +static struct intel_shared_regs *allocate_shared_regs(int cpu) +{ + struct intel_shared_regs *regs; + int i; + + regs = kzalloc_node(sizeof(struct intel_shared_regs), + GFP_KERNEL, cpu_to_node(cpu)); + if (regs) { + /* + * initialize the locks to keep lockdep happy + */ + for (i = 0; i < EXTRA_REG_MAX; i++) + raw_spin_lock_init(®s->regs[i].lock); + + regs->core_id = -1; + } + return regs; +} + static int intel_pmu_cpu_prepare(int cpu) { struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu); - if (!cpu_has_ht_siblings()) + if (!x86_pmu.extra_regs) return NOTIFY_OK; - cpuc->per_core = kzalloc_node(sizeof(struct intel_percore), - GFP_KERNEL, cpu_to_node(cpu)); - if (!cpuc->per_core) + cpuc->shared_regs = allocate_shared_regs(cpu); + if (!cpuc->shared_regs) return NOTIFY_BAD; - raw_spin_lock_init(&cpuc->per_core->lock); - cpuc->per_core->core_id = -1; return NOTIFY_OK; } @@ -1260,32 +1256,34 @@ static void intel_pmu_cpu_starting(int cpu) */ intel_pmu_lbr_reset(); - if (!cpu_has_ht_siblings()) + if (!cpuc->shared_regs) return; for_each_cpu(i, topology_thread_cpumask(cpu)) { - struct intel_percore *pc = per_cpu(cpu_hw_events, i).per_core; + struct intel_shared_regs *pc; + pc = per_cpu(cpu_hw_events, i).shared_regs; if (pc && pc->core_id == core_id) { - kfree(cpuc->per_core); - cpuc->per_core = pc; + kfree(cpuc->shared_regs); + cpuc->shared_regs = pc; break; } } - cpuc->per_core->core_id = core_id; - cpuc->per_core->refcnt++; + cpuc->shared_regs->core_id = core_id; + cpuc->shared_regs->refcnt++; } static void intel_pmu_cpu_dying(int cpu) { struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu); - struct intel_percore *pc = cpuc->per_core; + struct intel_shared_regs *pc; + pc = cpuc->shared_regs; if (pc) { if (pc->core_id == -1 || --pc->refcnt == 0) kfree(pc); - cpuc->per_core = NULL; + cpuc->shared_regs = NULL; } fini_debug_store_on_cpu(cpu); @@ -1436,7 +1434,6 @@ static __init int intel_pmu_init(void) x86_pmu.event_constraints = intel_nehalem_event_constraints; x86_pmu.pebs_constraints = intel_nehalem_pebs_event_constraints; - x86_pmu.percore_constraints = intel_nehalem_percore_constraints; x86_pmu.enable_all = intel_pmu_nhm_enable_all; x86_pmu.extra_regs = intel_nehalem_extra_regs; @@ -1481,7 +1478,6 @@ static __init int intel_pmu_init(void) intel_pmu_lbr_init_nhm(); x86_pmu.event_constraints = intel_westmere_event_constraints; - x86_pmu.percore_constraints = intel_westmere_percore_constraints; x86_pmu.enable_all = intel_pmu_nhm_enable_all; x86_pmu.pebs_constraints = intel_westmere_pebs_event_constraints; x86_pmu.extra_regs = intel_westmere_extra_regs; diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 771b0b2845e4..069315eefb22 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -536,6 +536,16 @@ struct perf_branch_stack { struct task_struct; +/* + * extra PMU register associated with an event + */ +struct hw_perf_event_extra { + u64 config; /* register value */ + unsigned int reg; /* register address or index */ + int alloc; /* extra register already allocated */ + int idx; /* index in shared_regs->regs[] */ +}; + /** * struct hw_perf_event - performance event hardware details: */ @@ -549,9 +559,7 @@ struct hw_perf_event { unsigned long event_base; int idx; int last_cpu; - unsigned int extra_reg; - u64 extra_config; - int extra_alloc; + struct hw_perf_event_extra extra_reg; }; struct { /* software */ struct hrtimer hrtimer; |