From ac199db0189c091f2863312061c0575937f68810 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 19 Mar 2009 20:26:15 +0100 Subject: [PATCH] ftrace: event profile hooks Impact: new tracing infrastructure feature Provide infrastructure to generate software perf counter events from tracepoints. Signed-off-by: Peter Zijlstra Cc: Paul Mackerras Cc: Steven Rostedt LKML-Reference: <20090319194233.557364871@chello.nl> Signed-off-by: Ingo Molnar --- kernel/trace/Makefile | 1 + kernel/trace/events.c | 1 - kernel/trace/trace.h | 11 ++++++++++ kernel/trace/trace_event_profile.c | 31 ++++++++++++++++++++++++++ kernel/trace/trace_events.c | 9 ++------ kernel/trace/trace_events_stage_3.h | 44 +++++++++++++++++++++++++++++++++++++ 6 files changed, 89 insertions(+), 8 deletions(-) create mode 100644 kernel/trace/trace_event_profile.c diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index c3feea0..0e45c20 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -44,5 +44,6 @@ obj-$(CONFIG_EVENT_TRACER) += trace_events.o obj-$(CONFIG_EVENT_TRACER) += events.o obj-$(CONFIG_EVENT_TRACER) += trace_export.o obj-$(CONFIG_FTRACE_SYSCALLS) += trace_syscalls.o +obj-$(CONFIG_EVENT_PROFILE) += trace_event_profile.o libftrace-y := ftrace.o diff --git a/kernel/trace/events.c b/kernel/trace/events.c index 9fc918d..246f2aa 100644 --- a/kernel/trace/events.c +++ b/kernel/trace/events.c @@ -12,4 +12,3 @@ #include "trace_events_stage_2.h" #include "trace_events_stage_3.h" -#include diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 7c9a0cb..7cfb741 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -785,12 +785,23 @@ struct ftrace_event_call { int id; int (*raw_init)(void); int (*show_format)(struct trace_seq *s); + +#ifdef CONFIG_EVENT_PROFILE + atomic_t profile_count; + int (*profile_enable)(struct ftrace_event_call *); + void (*profile_disable)(struct ftrace_event_call *); +#endif }; void event_trace_printk(unsigned long ip, const char *fmt, ...); extern struct ftrace_event_call __start_ftrace_events[]; extern struct ftrace_event_call __stop_ftrace_events[]; +#define for_each_event(event) \ + for (event = __start_ftrace_events; \ + (unsigned long)event < (unsigned long)__stop_ftrace_events; \ + event++) + extern const char *__start___trace_bprintk_fmt[]; extern const char *__stop___trace_bprintk_fmt[]; diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c new file mode 100644 index 0000000..22cba99 --- /dev/null +++ b/kernel/trace/trace_event_profile.c @@ -0,0 +1,31 @@ +/* + * trace event based perf counter profiling + * + * Copyright (C) 2009 Red Hat Inc, Peter Zijlstra + * + */ + +#include "trace.h" + +int ftrace_profile_enable(int event_id) +{ + struct ftrace_event_call *event; + + for_each_event(event) { + if (event->id == event_id) + return event->profile_enable(event); + } + + return -EINVAL; +} + +void ftrace_profile_disable(int event_id) +{ + struct ftrace_event_call *event; + + for_each_event(event) { + if (event->id == event_id) + return event->profile_disable(event); + } +} + diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 7763db8..3047b56 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -19,11 +19,6 @@ static DEFINE_MUTEX(event_mutex); -#define events_for_each(event) \ - for (event = __start_ftrace_events; \ - (unsigned long)event < (unsigned long)__stop_ftrace_events; \ - event++) - static void ftrace_clear_events(void) { struct ftrace_event_call *call = (void *)__start_ftrace_events; @@ -90,7 +85,7 @@ static int ftrace_set_clr_event(char *buf, int set) } mutex_lock(&event_mutex); - events_for_each(call) { + for_each_event(call) { if (!call->name || !call->regfunc) continue; @@ -628,7 +623,7 @@ static __init int event_trace_init(void) if (!d_events) return 0; - events_for_each(call) { + for_each_event(call) { /* The linker may leave blanks */ if (!call->name) continue; diff --git a/kernel/trace/trace_events_stage_3.h b/kernel/trace/trace_events_stage_3.h index 4c26d97..6b3261c 100644 --- a/kernel/trace/trace_events_stage_3.h +++ b/kernel/trace/trace_events_stage_3.h @@ -109,6 +109,40 @@ #undef TP_FMT #define TP_FMT(fmt, args...) fmt "\n", ##args +#ifdef CONFIG_EVENT_PROFILE +#define _TRACE_PROFILE(call, proto, args) \ +static void ftrace_profile_##call(proto) \ +{ \ + extern void perf_tpcounter_event(int); \ + perf_tpcounter_event(event_##call.id); \ +} \ + \ +static int ftrace_profile_enable_##call(struct ftrace_event_call *call) \ +{ \ + int ret = 0; \ + \ + if (!atomic_inc_return(&call->profile_count)) \ + ret = register_trace_##call(ftrace_profile_##call); \ + \ + return ret; \ +} \ + \ +static void ftrace_profile_disable_##call(struct ftrace_event_call *call) \ +{ \ + if (atomic_add_negative(-1, &call->profile_count)) \ + unregister_trace_##call(ftrace_profile_##call); \ +} + +#define _TRACE_PROFILE_INIT(call) \ + .profile_count = ATOMIC_INIT(-1), \ + .profile_enable = ftrace_profile_enable_##call, \ + .profile_disable = ftrace_profile_disable_##call, + +#else +#define _TRACE_PROFILE(call, proto, args) +#define _TRACE_PROFILE_INIT(call) +#endif + #define _TRACE_FORMAT(call, proto, args, fmt) \ static void ftrace_event_##call(proto) \ { \ @@ -147,6 +181,7 @@ static int ftrace_init_event_##call(void) \ #undef TRACE_FORMAT #define TRACE_FORMAT(call, proto, args, fmt) \ _TRACE_FORMAT(call, PARAMS(proto), PARAMS(args), PARAMS(fmt)) \ +_TRACE_PROFILE(call, PARAMS(proto), PARAMS(args)) \ static struct ftrace_event_call __used \ __attribute__((__aligned__(4))) \ __attribute__((section("_ftrace_events"))) event_##call = { \ @@ -155,6 +190,7 @@ __attribute__((section("_ftrace_events"))) event_##call = { \ .raw_init = ftrace_init_event_##call, \ .regfunc = ftrace_reg_event_##call, \ .unregfunc = ftrace_unreg_event_##call, \ + _TRACE_PROFILE_INIT(call) \ } #undef __entry @@ -162,6 +198,7 @@ __attribute__((section("_ftrace_events"))) event_##call = { \ #undef TRACE_EVENT #define TRACE_EVENT(call, proto, args, tstruct, assign, print) \ +_TRACE_PROFILE(call, PARAMS(proto), PARAMS(args)) \ \ static struct ftrace_event_call event_##call; \ \ @@ -227,4 +264,11 @@ __attribute__((section("_ftrace_events"))) event_##call = { \ .regfunc = ftrace_raw_reg_event_##call, \ .unregfunc = ftrace_raw_unreg_event_##call, \ .show_format = ftrace_format_##call, \ + _TRACE_PROFILE_INIT(call) \ } + +#include + +#undef _TRACE_PROFILE +#undef _TRACE_PROFILE_INIT + -- 2.7.4