From 38516ab59fbc5b3bb278cf5e1fe2867c70cff32e Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Tue, 20 Apr 2010 17:04:50 -0400 Subject: tracing: Let tracepoints have data passed to tracepoint callbacks This patch adds data to be passed to tracepoint callbacks. The created functions from DECLARE_TRACE() now need a mandatory data parameter. For example: DECLARE_TRACE(mytracepoint, int value, value) Will create the register function: int register_trace_mytracepoint((void(*)(void *data, int value))probe, void *data); As the first argument, all callbacks (probes) must take a (void *data) parameter. So a callback for the above tracepoint will look like: void myprobe(void *data, int value) { } The callback may choose to ignore the data parameter. This change allows callbacks to register a private data pointer along with the function probe. void mycallback(void *data, int value); register_trace_mytracepoint(mycallback, mydata); Then the mycallback() will receive the "mydata" as the first parameter before the args. A more detailed example: DECLARE_TRACE(mytracepoint, TP_PROTO(int status), TP_ARGS(status)); /* In the C file */ DEFINE_TRACE(mytracepoint, TP_PROTO(int status), TP_ARGS(status)); [...] trace_mytracepoint(status); /* In a file registering this tracepoint */ int my_callback(void *data, int status) { struct my_struct my_data = data; [...] } [...] my_data = kmalloc(sizeof(*my_data), GFP_KERNEL); init_my_data(my_data); register_trace_mytracepoint(my_callback, my_data); The same callback can also be registered to the same tracepoint as long as the data registered is different. Note, the data must also be used to unregister the callback: unregister_trace_mytracepoint(my_callback, my_data); Because of the data parameter, tracepoints declared this way can not have no args. That is: DECLARE_TRACE(mytracepoint, TP_PROTO(void), TP_ARGS()); will cause an error. If no arguments are needed, a new macro can be used instead: DECLARE_TRACE_NOARGS(mytracepoint); Since there are no arguments, the proto and args fields are left out. This is part of a series to make the tracepoint footprint smaller: text data bss dec hex filename 4913961 1088356 861512 6863829 68bbd5 vmlinux.orig 4914025 1088868 861512 6864405 68be15 vmlinux.class 4918492 1084612 861512 6864616 68bee8 vmlinux.tracepoint Again, this patch also increases the size of the kernel, but lays the ground work for decreasing it. v5: Fixed net/core/drop_monitor.c to handle these updates. v4: Moved the DECLARE_TRACE() DECLARE_TRACE_NOARGS out of the #ifdef CONFIG_TRACE_POINTS, since the two are the same in both cases. The __DECLARE_TRACE() is what changes. Thanks to Frederic Weisbecker for pointing this out. v3: Made all register_* functions require data to be passed and all callbacks to take a void * parameter as its first argument. This makes the calling functions comply with C standards. Also added more comments to the modifications of DECLARE_TRACE(). v2: Made the DECLARE_TRACE() have the ability to pass arguments and added a new DECLARE_TRACE_NOARGS() for tracepoints that do not need any arguments. Acked-by: Mathieu Desnoyers Acked-by: Masami Hiramatsu Acked-by: Frederic Weisbecker Cc: Neil Horman Cc: David S. Miller Signed-off-by: Steven Rostedt --- kernel/trace/kmemtrace.c | 42 ++++++++++++++++++++++++------------------ 1 file changed, 24 insertions(+), 18 deletions(-) (limited to 'kernel/trace/kmemtrace.c') diff --git a/kernel/trace/kmemtrace.c b/kernel/trace/kmemtrace.c index a91da69f153a..7253d0c1c32f 100644 --- a/kernel/trace/kmemtrace.c +++ b/kernel/trace/kmemtrace.c @@ -95,7 +95,8 @@ static inline void kmemtrace_free(enum kmemtrace_type_id type_id, trace_wake_up(); } -static void kmemtrace_kmalloc(unsigned long call_site, +static void kmemtrace_kmalloc(void *ignore, + unsigned long call_site, const void *ptr, size_t bytes_req, size_t bytes_alloc, @@ -105,7 +106,8 @@ static void kmemtrace_kmalloc(unsigned long call_site, bytes_req, bytes_alloc, gfp_flags, -1); } -static void kmemtrace_kmem_cache_alloc(unsigned long call_site, +static void kmemtrace_kmem_cache_alloc(void *ignore, + unsigned long call_site, const void *ptr, size_t bytes_req, size_t bytes_alloc, @@ -115,7 +117,8 @@ static void kmemtrace_kmem_cache_alloc(unsigned long call_site, bytes_req, bytes_alloc, gfp_flags, -1); } -static void kmemtrace_kmalloc_node(unsigned long call_site, +static void kmemtrace_kmalloc_node(void *ignore, + unsigned long call_site, const void *ptr, size_t bytes_req, size_t bytes_alloc, @@ -126,7 +129,8 @@ static void kmemtrace_kmalloc_node(unsigned long call_site, bytes_req, bytes_alloc, gfp_flags, node); } -static void kmemtrace_kmem_cache_alloc_node(unsigned long call_site, +static void kmemtrace_kmem_cache_alloc_node(void *ignore, + unsigned long call_site, const void *ptr, size_t bytes_req, size_t bytes_alloc, @@ -137,12 +141,14 @@ static void kmemtrace_kmem_cache_alloc_node(unsigned long call_site, bytes_req, bytes_alloc, gfp_flags, node); } -static void kmemtrace_kfree(unsigned long call_site, const void *ptr) +static void +kmemtrace_kfree(void *ignore, unsigned long call_site, const void *ptr) { kmemtrace_free(KMEMTRACE_TYPE_KMALLOC, call_site, ptr); } -static void kmemtrace_kmem_cache_free(unsigned long call_site, const void *ptr) +static void kmemtrace_kmem_cache_free(void *ignore, + unsigned long call_site, const void *ptr) { kmemtrace_free(KMEMTRACE_TYPE_CACHE, call_site, ptr); } @@ -151,34 +157,34 @@ static int kmemtrace_start_probes(void) { int err; - err = register_trace_kmalloc(kmemtrace_kmalloc); + err = register_trace_kmalloc(kmemtrace_kmalloc, NULL); if (err) return err; - err = register_trace_kmem_cache_alloc(kmemtrace_kmem_cache_alloc); + err = register_trace_kmem_cache_alloc(kmemtrace_kmem_cache_alloc, NULL); if (err) return err; - err = register_trace_kmalloc_node(kmemtrace_kmalloc_node); + err = register_trace_kmalloc_node(kmemtrace_kmalloc_node, NULL); if (err) return err; - err = register_trace_kmem_cache_alloc_node(kmemtrace_kmem_cache_alloc_node); + err = register_trace_kmem_cache_alloc_node(kmemtrace_kmem_cache_alloc_node, NULL); if (err) return err; - err = register_trace_kfree(kmemtrace_kfree); + err = register_trace_kfree(kmemtrace_kfree, NULL); if (err) return err; - err = register_trace_kmem_cache_free(kmemtrace_kmem_cache_free); + err = register_trace_kmem_cache_free(kmemtrace_kmem_cache_free, NULL); return err; } static void kmemtrace_stop_probes(void) { - unregister_trace_kmalloc(kmemtrace_kmalloc); - unregister_trace_kmem_cache_alloc(kmemtrace_kmem_cache_alloc); - unregister_trace_kmalloc_node(kmemtrace_kmalloc_node); - unregister_trace_kmem_cache_alloc_node(kmemtrace_kmem_cache_alloc_node); - unregister_trace_kfree(kmemtrace_kfree); - unregister_trace_kmem_cache_free(kmemtrace_kmem_cache_free); + unregister_trace_kmalloc(kmemtrace_kmalloc, NULL); + unregister_trace_kmem_cache_alloc(kmemtrace_kmem_cache_alloc, NULL); + unregister_trace_kmalloc_node(kmemtrace_kmalloc_node, NULL); + unregister_trace_kmem_cache_alloc_node(kmemtrace_kmem_cache_alloc_node, NULL); + unregister_trace_kfree(kmemtrace_kfree, NULL); + unregister_trace_kmem_cache_free(kmemtrace_kmem_cache_free, NULL); } static int kmem_trace_init(struct trace_array *tr) -- cgit v1.2.3 From a9a5776380208a3e48a92d0c763ee1a3b486fb73 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 22 Apr 2010 18:46:14 -0400 Subject: tracing: Allow events to share their print functions Multiple events may use the same method to print their data. Instead of having all events have a pointer to their print funtions, the trace_event structure now points to a trace_event_functions structure that will hold the way to print ouf the event. The event itself is now passed to the print function to let the print function know what kind of event it should print. This opens the door to consolidating the way several events print their output. text data bss dec hex filename 4913961 1088356 861512 6863829 68bbd5 vmlinux.orig 4900382 1048964 861512 6810858 67ecea vmlinux.init 4900446 1049028 861512 6810986 67ed6a vmlinux.preprint This change slightly increases the size but is needed for the next change. v3: Fix the branch tracer events to handle this change. v2: Fix the new function graph tracer event calls to handle this change. Acked-by: Mathieu Desnoyers Acked-by: Masami Hiramatsu Acked-by: Frederic Weisbecker Signed-off-by: Steven Rostedt --- kernel/trace/kmemtrace.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-) (limited to 'kernel/trace/kmemtrace.c') diff --git a/kernel/trace/kmemtrace.c b/kernel/trace/kmemtrace.c index 7253d0c1c32f..bbfc1bb1660b 100644 --- a/kernel/trace/kmemtrace.c +++ b/kernel/trace/kmemtrace.c @@ -243,7 +243,8 @@ struct kmemtrace_user_event_alloc { }; static enum print_line_t -kmemtrace_print_alloc(struct trace_iterator *iter, int flags) +kmemtrace_print_alloc(struct trace_iterator *iter, int flags, + struct trace_event *event) { struct trace_seq *s = &iter->seq; struct kmemtrace_alloc_entry *entry; @@ -263,7 +264,8 @@ kmemtrace_print_alloc(struct trace_iterator *iter, int flags) } static enum print_line_t -kmemtrace_print_free(struct trace_iterator *iter, int flags) +kmemtrace_print_free(struct trace_iterator *iter, int flags, + struct trace_event *event) { struct trace_seq *s = &iter->seq; struct kmemtrace_free_entry *entry; @@ -281,7 +283,8 @@ kmemtrace_print_free(struct trace_iterator *iter, int flags) } static enum print_line_t -kmemtrace_print_alloc_user(struct trace_iterator *iter, int flags) +kmemtrace_print_alloc_user(struct trace_iterator *iter, int flags, + struct trace_event *event) { struct trace_seq *s = &iter->seq; struct kmemtrace_alloc_entry *entry; @@ -315,7 +318,8 @@ kmemtrace_print_alloc_user(struct trace_iterator *iter, int flags) } static enum print_line_t -kmemtrace_print_free_user(struct trace_iterator *iter, int flags) +kmemtrace_print_free_user(struct trace_iterator *iter, int flags, + struct trace_event *event) { struct trace_seq *s = &iter->seq; struct kmemtrace_free_entry *entry; @@ -469,18 +473,26 @@ static enum print_line_t kmemtrace_print_line(struct trace_iterator *iter) } } -static struct trace_event kmem_trace_alloc = { - .type = TRACE_KMEM_ALLOC, +static struct trace_event_functions kmem_trace_alloc_funcs = { .trace = kmemtrace_print_alloc, .binary = kmemtrace_print_alloc_user, }; -static struct trace_event kmem_trace_free = { - .type = TRACE_KMEM_FREE, +static struct trace_event kmem_trace_alloc = { + .type = TRACE_KMEM_ALLOC, + .funcs = &kmem_trace_alloc_funcs, +}; + +static struct trace_event_functions kmem_trace_free_funcs = { .trace = kmemtrace_print_free, .binary = kmemtrace_print_free_user, }; +static struct trace_event kmem_trace_free = { + .type = TRACE_KMEM_FREE, + .funcs = &kmem_trace_free_funcs, +}; + static struct tracer kmem_tracer __read_mostly = { .name = "kmemtrace", .init = kmem_trace_init, -- cgit v1.2.3