perf_counter: revamp syscall input ABI

Impact: modify ABI

The hardware/software classification in hw_event->type became a little
strained due to the addition of tracepoint tracing.

Instead split up the field and provide a type field to explicitly specify
the counter type, while using the event_id field to specify which event to
use.

Raw counters still work as before, only the raw config now goes into
raw_event.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Orig-LKML-Reference: <20090319194233.836807573@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

4 files changed, 117 insertions, 75 deletions

diff --git a/arch/powerpc/kernel/perf_counter.c b/arch/powerpc/kernel/perf_counter.c
index 5008762e8bf4..26f69dc7130e 100644
--- a/arch/powerpc/kernel/perf_counter.c
+++ b/arch/powerpc/kernel/perf_counter.c
@@ -602,7 +602,7 @@ hw_perf_counter_init(struct perf_counter *counter)
                 return NULL;
         if ((s64)counter->hw_event.irq_period < 0)
                 return NULL;
-        ev = counter->hw_event.type;
+        ev = counter->hw_event.event_id;
         if (!counter->hw_event.raw) {
                 if (ev >= ppmu->n_generic ||
                     ppmu->generic_events[ev] == 0)
@@ -692,7 +692,7 @@ static void perf_handle_group(struct perf_counter *counter)
         list_for_each_entry(sub, &leader->sibling_list, list_entry) {
                 if (sub != counter)
                         sub->hw_ops->read(sub);
-                perf_store_irq_data(counter, sub->hw_event.type);
+                perf_store_irq_data(counter, sub->hw_event.event_config);
                 perf_store_irq_data(counter, atomic64_read(&sub->count));
         }
 }
diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c
index 6cba9d47b711..d844ae41d5a3 100644
--- a/arch/x86/kernel/cpu/perf_counter.c
+++ b/arch/x86/kernel/cpu/perf_counter.c
@@ -217,15 +217,15 @@ static int __hw_perf_counter_init(struct perf_counter *counter)
         /*
          * Raw event type provide the config in the event structure
          */
-        if (hw_event->raw) {
-                hwc->config |= pmc_ops->raw_event(hw_event->type);
+        if (hw_event->raw_type) {
+                hwc->config |= pmc_ops->raw_event(hw_event->raw_event_id);
         } else {
-                if (hw_event->type >= pmc_ops->max_events)
+                if (hw_event->event_id >= pmc_ops->max_events)
                         return -EINVAL;
                 /*
                  * The generic map:
                  */
-                hwc->config |= pmc_ops->event_map(hw_event->type);
+                hwc->config |= pmc_ops->event_map(hw_event->event_id);
         }
         counter->wakeup_pending = 0;
 
@@ -715,7 +715,7 @@ perf_handle_group(struct perf_counter *sibling, u64 *status, u64 *overflown)
         list_for_each_entry(counter, &group_leader->sibling_list, list_entry) {
 
                 x86_perf_counter_update(counter, &counter->hw, counter->hw.idx);
-                perf_store_irq_data(sibling, counter->hw_event.type);
+                perf_store_irq_data(sibling, counter->hw_event.event_config);
                 perf_store_irq_data(sibling, atomic64_read(&counter->count));
         }
 }
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
index 065984c1ff57..8f9394905502 100644
--- a/include/linux/perf_counter.h
+++ b/include/linux/perf_counter.h
@@ -21,56 +21,81 @@
  */
 
 /*
- * Generalized performance counter event types, used by the hw_event.type
- * parameter of the sys_perf_counter_open() syscall:
+ * hw_event.type
  */
-enum hw_event_types {
+enum perf_event_types {
+        PERF_TYPE_HARDWARE              = 0,
+        PERF_TYPE_SOFTWARE              = 1,
+        PERF_TYPE_TRACEPOINT            = 2,
+
         /*
-         * Common hardware events, generalized by the kernel:
+         * available TYPE space, raw is the max value.
          */
-        PERF_COUNT_CPU_CYCLES           =  0,
-        PERF_COUNT_INSTRUCTIONS         =  1,
-        PERF_COUNT_CACHE_REFERENCES     =  2,
-        PERF_COUNT_CACHE_MISSES         =  3,
-        PERF_COUNT_BRANCH_INSTRUCTIONS  =  4,
-        PERF_COUNT_BRANCH_MISSES        =  5,
-        PERF_COUNT_BUS_CYCLES           =  6,
 
-        PERF_HW_EVENTS_MAX              =  7,
+        PERF_TYPE_RAW                   = 128,
+};
 
+/*
+ * Generalized performance counter event types, used by the hw_event.event_id
+ * parameter of the sys_perf_counter_open() syscall:
+ */
+enum hw_event_ids {
         /*
-         * Special "software" counters provided by the kernel, even if
-         * the hardware does not support performance counters. These
-         * counters measure various physical and sw events of the
-         * kernel (and allow the profiling of them as well):
+         * Common hardware events, generalized by the kernel:
          */
-        PERF_COUNT_CPU_CLOCK            = -1,
-        PERF_COUNT_TASK_CLOCK           = -2,
-        PERF_COUNT_PAGE_FAULTS          = -3,
-        PERF_COUNT_CONTEXT_SWITCHES     = -4,
-        PERF_COUNT_CPU_MIGRATIONS       = -5,
-        PERF_COUNT_PAGE_FAULTS_MIN      = -6,
-        PERF_COUNT_PAGE_FAULTS_MAJ      = -7,
-
-        PERF_SW_EVENTS_MIN              = -8,
+        PERF_COUNT_CPU_CYCLES           = 0,
+        PERF_COUNT_INSTRUCTIONS         = 1,
+        PERF_COUNT_CACHE_REFERENCES     = 2,
+        PERF_COUNT_CACHE_MISSES         = 3,
+        PERF_COUNT_BRANCH_INSTRUCTIONS  = 4,
+        PERF_COUNT_BRANCH_MISSES        = 5,
+        PERF_COUNT_BUS_CYCLES           = 6,
+
+        PERF_HW_EVENTS_MAX              = 7,
+};
 
-        PERF_TP_EVENTS_MIN              = -65536
+/*
+ * Special "software" counters provided by the kernel, even if the hardware
+ * does not support performance counters. These counters measure various
+ * physical and sw events of the kernel (and allow the profiling of them as
+ * well):
+ */
+enum sw_event_ids {
+        PERF_COUNT_CPU_CLOCK            = 0,
+        PERF_COUNT_TASK_CLOCK           = 1,
+        PERF_COUNT_PAGE_FAULTS          = 2,
+        PERF_COUNT_CONTEXT_SWITCHES     = 3,
+        PERF_COUNT_CPU_MIGRATIONS       = 4,
+        PERF_COUNT_PAGE_FAULTS_MIN      = 5,
+        PERF_COUNT_PAGE_FAULTS_MAJ      = 6,
+
+        PERF_SW_EVENTS_MAX              = 7,
 };
 
 /*
  * IRQ-notification data record type:
  */
 enum perf_counter_record_type {
-        PERF_RECORD_SIMPLE              =  0,
-        PERF_RECORD_IRQ                 =  1,
-        PERF_RECORD_GROUP               =  2,
+        PERF_RECORD_SIMPLE              = 0,
+        PERF_RECORD_IRQ                 = 1,
+        PERF_RECORD_GROUP               = 2,
 };
 
 /*
  * Hardware event to monitor via a performance monitoring counter:
  */
 struct perf_counter_hw_event {
-        __s64                   type;
+        union {
+                struct {
+                        __u64                   event_id        : 56,
+                                                type            :  8;
+                };
+                struct {
+                        __u64                   raw_event_id    : 63,
+                                                raw_type        :  1;
+                };
+                __u64           event_config;
+        };
 
         __u64                   irq_period;
         __u64                   record_type;
@@ -78,7 +103,6 @@ struct perf_counter_hw_event {
 
         __u64                   disabled       :  1, /* off by default        */
                                 nmi            :  1, /* NMI sampling          */
-                                raw            :  1, /* raw event type        */
                                 inherit        :  1, /* children inherit it   */
                                 pinned         :  1, /* must always be on PMU */
                                 exclusive      :  1, /* only group on PMU     */
@@ -87,7 +111,7 @@ struct perf_counter_hw_event {
                                 exclude_hv     :  1, /* ditto hypervisor      */
                                 exclude_idle   :  1, /* don't count when idle */
 
-                                __reserved_1   : 54;
+                                __reserved_1   : 55;
 
         __u32                   extra_config_len;
         __u32                   __reserved_4;
@@ -298,10 +322,11 @@ extern int hw_perf_group_sched_in(struct perf_counter *group_leader,
  */
 static inline int is_software_counter(struct perf_counter *counter)
 {
-        return !counter->hw_event.raw && counter->hw_event.type < 0;
+        return !counter->hw_event.raw_type &&
+                counter->hw_event.type != PERF_TYPE_HARDWARE;
 }
 
-extern void perf_swcounter_event(enum hw_event_types, u64, int, struct pt_regs *);
+extern void perf_swcounter_event(u32, u64, int, struct pt_regs *);
 
 #else
 static inline void
@@ -320,7 +345,7 @@ static inline u64 hw_perf_save_disable(void)		      { return 0; }
 static inline int perf_counter_task_disable(void)       { return -EINVAL; }
 static inline int perf_counter_task_enable(void)        { return -EINVAL; }
 
-static inline void perf_swcounter_event(enum hw_event_types event, u64 nr,
+static inline void perf_swcounter_event(u32 event, u64 nr,
                                         int nmi, struct pt_regs *regs)  { }
 #endif
 
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 0bbe3e45ba0d..68a56a68bc74 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -1395,12 +1395,6 @@ static void perf_swcounter_set_period(struct perf_counter *counter)
         atomic64_set(&hwc->count, -left);
 }
 
-static void perf_swcounter_save_and_restart(struct perf_counter *counter)
-{
-        perf_swcounter_update(counter);
-        perf_swcounter_set_period(counter);
-}
-
 static void perf_swcounter_store_irq(struct perf_counter *counter, u64 data)
 {
         struct perf_data *irqdata = counter->irqdata;
@@ -1421,7 +1415,7 @@ static void perf_swcounter_handle_group(struct perf_counter *sibling)
 
         list_for_each_entry(counter, &group_leader->sibling_list, list_entry) {
                 counter->hw_ops->read(counter);
-                perf_swcounter_store_irq(sibling, counter->hw_event.type);
+                perf_swcounter_store_irq(sibling, counter->hw_event.event_config);
                 perf_swcounter_store_irq(sibling, atomic64_read(&counter->count));
         }
 }
@@ -1477,21 +1471,25 @@ static enum hrtimer_restart perf_swcounter_hrtimer(struct hrtimer *hrtimer)
 static void perf_swcounter_overflow(struct perf_counter *counter,
                                     int nmi, struct pt_regs *regs)
 {
-        perf_swcounter_save_and_restart(counter);
+        perf_swcounter_update(counter);
+        perf_swcounter_set_period(counter);
         perf_swcounter_interrupt(counter, nmi, regs);
 }
 
 static int perf_swcounter_match(struct perf_counter *counter,
-                                enum hw_event_types event,
-                                struct pt_regs *regs)
+                                enum perf_event_types type,
+                                u32 event, struct pt_regs *regs)
 {
         if (counter->state != PERF_COUNTER_STATE_ACTIVE)
                 return 0;
 
-        if (counter->hw_event.raw)
+        if (counter->hw_event.raw_type)
+                return 0;
+
+        if (counter->hw_event.type != type)
                 return 0;
 
-        if (counter->hw_event.type != event)
+        if (counter->hw_event.event_id != event)
                 return 0;
 
         if (counter->hw_event.exclude_user && user_mode(regs))
@@ -1512,8 +1510,8 @@ static void perf_swcounter_add(struct perf_counter *counter, u64 nr,
 }
 
 static void perf_swcounter_ctx_event(struct perf_counter_context *ctx,
-                                     enum hw_event_types event, u64 nr,
-                                     int nmi, struct pt_regs *regs)
+                                     enum perf_event_types type, u32 event,
+                                     u64 nr, int nmi, struct pt_regs *regs)
 {
         struct perf_counter *counter;
 
@@ -1522,24 +1520,31 @@ static void perf_swcounter_ctx_event(struct perf_counter_context *ctx,
 
         rcu_read_lock();
         list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) {
-                if (perf_swcounter_match(counter, event, regs))
+                if (perf_swcounter_match(counter, type, event, regs))
                         perf_swcounter_add(counter, nr, nmi, regs);
         }
         rcu_read_unlock();
 }
 
-void perf_swcounter_event(enum hw_event_types event, u64 nr,
-                          int nmi, struct pt_regs *regs)
+static void __perf_swcounter_event(enum perf_event_types type, u32 event,
+                                   u64 nr, int nmi, struct pt_regs *regs)
 {
         struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context);
 
-        perf_swcounter_ctx_event(&cpuctx->ctx, event, nr, nmi, regs);
-        if (cpuctx->task_ctx)
-                perf_swcounter_ctx_event(cpuctx->task_ctx, event, nr, nmi, regs);
+        perf_swcounter_ctx_event(&cpuctx->ctx, type, event, nr, nmi, regs);
+        if (cpuctx->task_ctx) {
+                perf_swcounter_ctx_event(cpuctx->task_ctx, type, event,
+                                nr, nmi, regs);
+        }
 
         put_cpu_var(perf_cpu_context);
 }
 
+void perf_swcounter_event(u32 event, u64 nr, int nmi, struct pt_regs *regs)
+{
+        __perf_swcounter_event(PERF_TYPE_SOFTWARE, event, nr, nmi, regs);
+}
+
 static void perf_swcounter_read(struct perf_counter *counter)
 {
         perf_swcounter_update(counter);
@@ -1733,8 +1738,12 @@ static const struct hw_perf_counter_ops perf_ops_cpu_migrations = {
 #ifdef CONFIG_EVENT_PROFILE
 void perf_tpcounter_event(int event_id)
 {
-        perf_swcounter_event(PERF_TP_EVENTS_MIN + event_id, 1, 1,
-                        task_pt_regs(current));
+        struct pt_regs *regs = get_irq_regs();
+
+        if (!regs)
+                regs = task_pt_regs(current);
+
+        __perf_swcounter_event(PERF_TYPE_TRACEPOINT, event_id, 1, 1, regs);
 }
 
 extern int ftrace_profile_enable(int);
@@ -1742,15 +1751,13 @@ extern void ftrace_profile_disable(int);
 
 static void tp_perf_counter_destroy(struct perf_counter *counter)
 {
-        int event_id = counter->hw_event.type - PERF_TP_EVENTS_MIN;
-
-        ftrace_profile_disable(event_id);
+        ftrace_profile_disable(counter->hw_event.event_id);
 }
 
 static const struct hw_perf_counter_ops *
 tp_perf_counter_init(struct perf_counter *counter)
 {
-        int event_id = counter->hw_event.type - PERF_TP_EVENTS_MIN;
+        int event_id = counter->hw_event.event_id;
         int ret;
 
         ret = ftrace_profile_enable(event_id);
@@ -1758,6 +1765,7 @@ tp_perf_counter_init(struct perf_counter *counter)
                 return NULL;
 
         counter->destroy = tp_perf_counter_destroy;
+        counter->hw.irq_period = counter->hw_event.irq_period;
 
         return &perf_ops_generic;
 }
@@ -1783,7 +1791,7 @@ sw_perf_counter_init(struct perf_counter *counter)
          * to be kernel events, and page faults are never hypervisor
          * events.
          */
-        switch (counter->hw_event.type) {
+        switch (counter->hw_event.event_id) {
         case PERF_COUNT_CPU_CLOCK:
                 hw_ops = &perf_ops_cpu_clock;
 
@@ -1813,9 +1821,6 @@ sw_perf_counter_init(struct perf_counter *counter)
                 if (!counter->hw_event.exclude_kernel)
                         hw_ops = &perf_ops_cpu_migrations;
                 break;
-        default:
-                hw_ops = tp_perf_counter_init(counter);
-                break;
         }
 
         if (hw_ops)
@@ -1870,10 +1875,22 @@ perf_counter_alloc(struct perf_counter_hw_event *hw_event,
                 counter->state = PERF_COUNTER_STATE_OFF;
 
         hw_ops = NULL;
-        if (!hw_event->raw && hw_event->type < 0)
-                hw_ops = sw_perf_counter_init(counter);
-        else
+
+        if (hw_event->raw_type)
+                hw_ops = hw_perf_counter_init(counter);
+        else switch (hw_event->type) {
+        case PERF_TYPE_HARDWARE:
                 hw_ops = hw_perf_counter_init(counter);
+                break;
+
+        case PERF_TYPE_SOFTWARE:
+                hw_ops = sw_perf_counter_init(counter);
+                break;
+
+        case PERF_TYPE_TRACEPOINT:
+                hw_ops = tp_perf_counter_init(counter);
+                break;
+        }
 
         if (!hw_ops) {
                 kfree(counter);