tracing, perf: Convert the power tracer into an event tracer

This patch converts the existing power tracer into an event tracer,
so that power events (C states and frequency changes) can be
tracked via "perf".

This also removes the perl script that was used to demo the tracer;
its functionality is being replaced entirely with timechart.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20090912130542.6d314860@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

5 files changed, 21 insertions, 239 deletions

diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 844164dca90a..26f03ac07c2b 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -42,7 +42,6 @@ obj-$(CONFIG_BOOT_TRACER) += trace_boot.o
 obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += trace_functions_graph.o
 obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o
 obj-$(CONFIG_HW_BRANCH_TRACER) += trace_hw_branches.o
-obj-$(CONFIG_POWER_TRACER) += trace_power.o
 obj-$(CONFIG_KMEMTRACE) += kmemtrace.o
 obj-$(CONFIG_WORKQUEUE_TRACER) += trace_workqueue.o
 obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
@@ -54,5 +53,6 @@ obj-$(CONFIG_EVENT_TRACING) += trace_export.o
 obj-$(CONFIG_FTRACE_SYSCALLS) += trace_syscalls.o
 obj-$(CONFIG_EVENT_PROFILE) += trace_event_profile.o
 obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o
+obj-$(CONFIG_EVENT_TRACING) += power-traces.o
 
 libftrace-y := ftrace.o
diff --git a/kernel/trace/power-traces.c b/kernel/trace/power-traces.c
new file mode 100644
index 000000000000..e06c6e3d56a3
--- /dev/null
+++ b/kernel/trace/power-traces.c
@@ -0,0 +1,20 @@
+/*
+ * Power trace points
+ *
+ * Copyright (C) 2009 Arjan van de Ven <arjan@linux.intel.com>
+ */
+
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/power.h>
+
+EXPORT_TRACEPOINT_SYMBOL_GPL(power_start);
+EXPORT_TRACEPOINT_SYMBOL_GPL(power_end);
+EXPORT_TRACEPOINT_SYMBOL_GPL(power_frequency);
+
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 86bcff94791a..405cb850b75d 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -11,7 +11,6 @@
 #include <linux/ftrace.h>
 #include <trace/boot.h>
 #include <linux/kmemtrace.h>
-#include <trace/power.h>
 
 #include <linux/trace_seq.h>
 #include <linux/ftrace_event.h>
@@ -37,7 +36,6 @@ enum trace_type {
         TRACE_HW_BRANCHES,
         TRACE_KMEM_ALLOC,
         TRACE_KMEM_FREE,
-        TRACE_POWER,
         TRACE_BLK,
 
         __TRACE_LAST_TYPE,
@@ -207,7 +205,6 @@ extern void __ftrace_bad_type(void);
                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
                           TRACE_GRAPH_RET);             \
                 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
-                IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
                           TRACE_KMEM_ALLOC);    \
                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h
index a431748ddd6e..ead3d724599d 100644
--- a/kernel/trace/trace_entries.h
+++ b/kernel/trace/trace_entries.h
@@ -330,23 +330,6 @@ FTRACE_ENTRY(hw_branch, hw_branch_entry,
         F_printk("from: %llx to: %llx", __entry->from, __entry->to)
 );
 
-FTRACE_ENTRY(power, trace_power,
-
-        TRACE_POWER,
-
-        F_STRUCT(
-                __field_struct( struct power_trace,     state_data      )
-                __field_desc(   s64,    state_data,     stamp           )
-                __field_desc(   s64,    state_data,     end             )
-                __field_desc(   int,    state_data,     type            )
-                __field_desc(   int,    state_data,     state           )
-        ),
-
-        F_printk("%llx->%llx type:%u state:%u",
-                 __entry->stamp, __entry->end,
-                 __entry->type, __entry->state)
-);
-
 FTRACE_ENTRY(kmem_alloc, kmemtrace_alloc_entry,
 
         TRACE_KMEM_ALLOC,
diff --git a/kernel/trace/trace_power.c b/kernel/trace/trace_power.c
deleted file mode 100644
index fe1a00f1445a..000000000000
--- a/kernel/trace/trace_power.c
+++ /dev/null
@@ -1,218 +0,0 @@
-/*
- * ring buffer based C-state tracer
- *
- * Arjan van de Ven <arjan@linux.intel.com>
- * Copyright (C) 2008 Intel Corporation
- *
- * Much is borrowed from trace_boot.c which is
- * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
- *
- */
-
-#include <linux/init.h>
-#include <linux/debugfs.h>
-#include <trace/power.h>
-#include <linux/kallsyms.h>
-#include <linux/module.h>
-
-#include "trace.h"
-#include "trace_output.h"
-
-static struct trace_array *power_trace;
-static int __read_mostly trace_power_enabled;
-
-static void probe_power_start(struct power_trace *it, unsigned int type,
-                                unsigned int level)
-{
-        if (!trace_power_enabled)
-                return;
-
-        memset(it, 0, sizeof(struct power_trace));
-        it->state = level;
-        it->type = type;
-        it->stamp = ktime_get();
-}
-
-
-static void probe_power_end(struct power_trace *it)
-{
-        struct ftrace_event_call *call = &event_power;
-        struct ring_buffer_event *event;
-        struct ring_buffer *buffer;
-        struct trace_power *entry;
-        struct trace_array_cpu *data;
-        struct trace_array *tr = power_trace;
-
-        if (!trace_power_enabled)
-                return;
-
-        buffer = tr->buffer;
-
-        preempt_disable();
-        it->end = ktime_get();
-        data = tr->data[smp_processor_id()];
-
-        event = trace_buffer_lock_reserve(buffer, TRACE_POWER,
-                                          sizeof(*entry), 0, 0);
-        if (!event)
-                goto out;
-        entry   = ring_buffer_event_data(event);
-        entry->state_data = *it;
-        if (!filter_check_discard(call, entry, buffer, event))
-                trace_buffer_unlock_commit(buffer, event, 0, 0);
- out:
-        preempt_enable();
-}
-
-static void probe_power_mark(struct power_trace *it, unsigned int type,
-                                unsigned int level)
-{
-        struct ftrace_event_call *call = &event_power;
-        struct ring_buffer_event *event;
-        struct ring_buffer *buffer;
-        struct trace_power *entry;
-        struct trace_array_cpu *data;
-        struct trace_array *tr = power_trace;
-
-        if (!trace_power_enabled)
-                return;
-
-        buffer = tr->buffer;
-
-        memset(it, 0, sizeof(struct power_trace));
-        it->state = level;
-        it->type = type;
-        it->stamp = ktime_get();
-        preempt_disable();
-        it->end = it->stamp;
-        data = tr->data[smp_processor_id()];
-
-        event = trace_buffer_lock_reserve(buffer, TRACE_POWER,
-                                          sizeof(*entry), 0, 0);
-        if (!event)
-                goto out;
-        entry   = ring_buffer_event_data(event);
-        entry->state_data = *it;
-        if (!filter_check_discard(call, entry, buffer, event))
-                trace_buffer_unlock_commit(buffer, event, 0, 0);
- out:
-        preempt_enable();
-}
-
-static int tracing_power_register(void)
-{
-        int ret;
-
-        ret = register_trace_power_start(probe_power_start);
-        if (ret) {
-                pr_info("power trace: Couldn't activate tracepoint"
-                        " probe to trace_power_start\n");
-                return ret;
-        }
-        ret = register_trace_power_end(probe_power_end);
-        if (ret) {
-                pr_info("power trace: Couldn't activate tracepoint"
-                        " probe to trace_power_end\n");
-                goto fail_start;
-        }
-        ret = register_trace_power_mark(probe_power_mark);
-        if (ret) {
-                pr_info("power trace: Couldn't activate tracepoint"
-                        " probe to trace_power_mark\n");
-                goto fail_end;
-        }
-        return ret;
-fail_end:
-        unregister_trace_power_end(probe_power_end);
-fail_start:
-        unregister_trace_power_start(probe_power_start);
-        return ret;
-}
-
-static void start_power_trace(struct trace_array *tr)
-{
-        trace_power_enabled = 1;
-}
-
-static void stop_power_trace(struct trace_array *tr)
-{
-        trace_power_enabled = 0;
-}
-
-static void power_trace_reset(struct trace_array *tr)
-{
-        trace_power_enabled = 0;
-        unregister_trace_power_start(probe_power_start);
-        unregister_trace_power_end(probe_power_end);
-        unregister_trace_power_mark(probe_power_mark);
-}
-
-
-static int power_trace_init(struct trace_array *tr)
-{
-        power_trace = tr;
-
-        trace_power_enabled = 1;
-        tracing_power_register();
-
-        tracing_reset_online_cpus(tr);
-        return 0;
-}
-
-static enum print_line_t power_print_line(struct trace_iterator *iter)
-{
-        int ret = 0;
-        struct trace_entry *entry = iter->ent;
-        struct trace_power *field ;
-        struct power_trace *it;
-        struct trace_seq *s = &iter->seq;
-        struct timespec stamp;
-        struct timespec duration;
-
-        trace_assign_type(field, entry);
-        it = &field->state_data;
-        stamp = ktime_to_timespec(it->stamp);
-        duration = ktime_to_timespec(ktime_sub(it->end, it->stamp));
-
-        if (entry->type == TRACE_POWER) {
-                if (it->type == POWER_CSTATE)
-                        ret = trace_seq_printf(s, "[%5ld.%09ld] CSTATE: Going to C%i on cpu %i for %ld.%09ld\n",
-                                          stamp.tv_sec,
-                                          stamp.tv_nsec,
-                                          it->state, iter->cpu,
-                                          duration.tv_sec,
-                                          duration.tv_nsec);
-                if (it->type == POWER_PSTATE)
-                        ret = trace_seq_printf(s, "[%5ld.%09ld] PSTATE: Going to P%i on cpu %i\n",
-                                          stamp.tv_sec,
-                                          stamp.tv_nsec,
-                                          it->state, iter->cpu);
-                if (!ret)
-                        return TRACE_TYPE_PARTIAL_LINE;
-                return TRACE_TYPE_HANDLED;
-        }
-        return TRACE_TYPE_UNHANDLED;
-}
-
-static void power_print_header(struct seq_file *s)
-{
-        seq_puts(s, "#   TIMESTAMP      STATE  EVENT\n");
-        seq_puts(s, "#       |            |      |\n");
-}
-
-static struct tracer power_tracer __read_mostly =
-{
-        .name           = "power",
-        .init           = power_trace_init,
-        .start          = start_power_trace,
-        .stop           = stop_power_trace,
-        .reset          = power_trace_reset,
-        .print_line     = power_print_line,
-        .print_header   = power_print_header,
-};
-
-static int init_power_trace(void)
-{
-        return register_tracer(&power_tracer);
-}
-device_initcall(init_power_trace);