From 3fd40d1ee6a317523172ab95b6f7ea41ba8fcee3 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 9 Aug 2012 22:42:57 -0400 Subject: [PATCH] tracing: Use helper functions in event assignment to shrink macro size The functions that assign the contents for the ftrace events are defined by the TRACE_EVENT() macros. Each event has its own unique way to assign data to its buffer. When you have over 500 events, that means there's 500 functions assigning data uniquely for each event (not really that many, as DECLARE_EVENT_CLASS() and multiple DEFINE_EVENT()s will only need a single function). By making helper functions in the core kernel to do some of the work instead, we can shrink the size of the kernel down a bit. With a kernel configured with 502 events, the change in size was: text data bss dec hex filename 12987390 1913504 9785344 24686238 178ae9e /tmp/vmlinux 12959102 1913504 9785344 24657950 178401e /tmp/vmlinux.patched That's a total of 28288 bytes, which comes down to 56 bytes per event. Link: http://lkml.kernel.org/r/20120810034708.370808175@goodmis.org Signed-off-by: Steven Rostedt --- include/linux/ftrace_event.h | 15 +++++++++++++++ include/trace/ftrace.h | 22 ++++++---------------- kernel/trace/trace_events.c | 30 ++++++++++++++++++++++++++++++ 3 files changed, 51 insertions(+), 16 deletions(-) diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index ffe642eb84fa..9d3fe0658398 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -206,6 +206,21 @@ int ftrace_event_define_field(struct ftrace_event_call *call, char *type, int len, char *item, int offset, int field_size, int sign, int filter); +struct ftrace_event_buffer { + struct ring_buffer *buffer; + struct ring_buffer_event *event; + struct ftrace_event_file *ftrace_file; + void *entry; + unsigned long flags; + int pc; +}; + +void *ftrace_event_buffer_reserve(struct ftrace_event_buffer *fbuffer, + struct ftrace_event_file *ftrace_file, + unsigned long len); + +void ftrace_event_buffer_commit(struct ftrace_event_buffer *fbuffer); + enum { TRACE_EVENT_FL_FILTERED_BIT, TRACE_EVENT_FL_CAP_ANY_BIT, diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h index 54928faf2119..1cc2265caa52 100644 --- a/include/trace/ftrace.h +++ b/include/trace/ftrace.h @@ -532,37 +532,27 @@ static notrace void \ ftrace_raw_event_##call(void *__data, proto) \ { \ struct ftrace_event_file *ftrace_file = __data; \ - struct ftrace_event_call *event_call = ftrace_file->event_call; \ struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\ - struct ring_buffer_event *event; \ + struct ftrace_event_buffer fbuffer; \ struct ftrace_raw_##call *entry; \ - struct ring_buffer *buffer; \ - unsigned long irq_flags; \ int __data_size; \ - int pc; \ \ if (ftrace_trigger_soft_disabled(ftrace_file)) \ return; \ \ - local_save_flags(irq_flags); \ - pc = preempt_count(); \ - \ __data_size = ftrace_get_offsets_##call(&__data_offsets, args); \ \ - event = trace_event_buffer_lock_reserve(&buffer, ftrace_file, \ - event_call->event.type, \ - sizeof(*entry) + __data_size, \ - irq_flags, pc); \ - if (!event) \ + entry = ftrace_event_buffer_reserve(&fbuffer, ftrace_file, \ + sizeof(*entry) + __data_size); \ + \ + if (!entry) \ return; \ - entry = ring_buffer_event_data(event); \ \ tstruct \ \ { assign; } \ \ - event_trigger_unlock_commit(ftrace_file, buffer, event, entry, \ - irq_flags, pc); \ + ftrace_event_buffer_commit(&fbuffer); \ } /* * The ftrace_test_probe is compiled out, it is only here as a build time check diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 22826c73a9da..b8f73b333a3c 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -188,6 +188,36 @@ int trace_event_raw_init(struct ftrace_event_call *call) } EXPORT_SYMBOL_GPL(trace_event_raw_init); +void *ftrace_event_buffer_reserve(struct ftrace_event_buffer *fbuffer, + struct ftrace_event_file *ftrace_file, + unsigned long len) +{ + struct ftrace_event_call *event_call = ftrace_file->event_call; + + local_save_flags(fbuffer->flags); + fbuffer->pc = preempt_count(); + fbuffer->ftrace_file = ftrace_file; + + fbuffer->event = + trace_event_buffer_lock_reserve(&fbuffer->buffer, ftrace_file, + event_call->event.type, len, + fbuffer->flags, fbuffer->pc); + if (!fbuffer->event) + return NULL; + + fbuffer->entry = ring_buffer_event_data(fbuffer->event); + return fbuffer->entry; +} +EXPORT_SYMBOL_GPL(ftrace_event_buffer_reserve); + +void ftrace_event_buffer_commit(struct ftrace_event_buffer *fbuffer) +{ + event_trigger_unlock_commit(fbuffer->ftrace_file, fbuffer->buffer, + fbuffer->event, fbuffer->entry, + fbuffer->flags, fbuffer->pc); +} +EXPORT_SYMBOL_GPL(ftrace_event_buffer_commit); + int ftrace_event_reg(struct ftrace_event_call *call, enum trace_reg type, void *data) {