linux/kernel/trace/trace_sched_switch.c, branch v3.6-rc5

tracing: Remove obsolete sched_switch tracer

2011-02-08T22:14:56Z

The trace events sched_switch and sched_wakeup do the same thing as the stand alone sched_switch tracer does. It is no longer needed. Signed-off-by: Steven Rostedt

tracing: Let tracepoints have data passed to tracepoint callbacks

2010-05-14T13:50:34Z

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

sched: Remove rq argument to the tracepoints

2010-05-07T09:28:17Z

struct rq isn't visible outside of sched.o so its near useless to expose the pointer, also there are no users of it, so remove it. Acked-by: Steven Rostedt Signed-off-by: Peter Zijlstra LKML-Reference: <1272997616.1642.207.camel@laptop> Signed-off-by: Ingo Molnar

tracing: pass around ring buffer instead of tracer

2009-09-04T22:59:39Z

The latency tracers (irqsoff and wakeup) can swap trace buffers on the fly. If an event is happening and has reserved data on one of the buffers, and the latency tracer swaps the global buffer with the max buffer, the result is that the event may commit the data to the wrong buffer. This patch changes the API to the trace recording to be recieve the buffer that was used to reserve a commit. Then this buffer can be passed in to the commit. Signed-off-by: Steven Rostedt

tracing: Move sched event insertion helpers in the sched switch tracer file

2009-08-06T05:28:06Z

The sched events helpers which insert the sched switch and wakeup events into the ring buffer currently reside in trace.c But this file is quite overloaded and the right place for these helpers is in the sched switch tracer file. Then move them to trace_functions.c Signed-off-by: Frederic Weisbecker Cc: Steven Rostedt

tracing/events: move trace point headers into include/trace/events

2009-04-15T02:05:43Z

Impact: clean up Create a sub directory in include/trace called events to keep the trace point headers in their own separate directory. Only headers that declare trace points should be defined in this directory. Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Neil Horman Cc: Zhao Lei Cc: Eduard - Gabriel Munteanu Cc: Pekka Enberg Signed-off-by: Steven Rostedt

ftrace: clean up enable logic for sched_switch

2009-04-07T12:43:09Z

Unify sched_switch and sched_wakeup's action to following logic: Do record_cmdline when start_cmdline_record() is called. Start tracing events when the tracer is started. Signed-off-by: Zhao Lei LKML-Reference: <49D1C596.5050203@cn.fujitsu.com> Signed-off-by: Steven Rostedt

ftrace: Add check of sched_stopped for probe_sched_wakeup

2009-04-07T12:01:11Z

The wakeup tracing in sched_switch does not stop when a user disables tracing. This is because the probe_sched_wakeup() is missing the check to prevent the wakeup from being traced. Signed-off-by: Zhao Lei LKML-Reference: <49D1C543.3010307@cn.fujitsu.com> Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar

tracing: make sched_switch stop/start light weight

2009-03-18T03:10:45Z

The stopping and starting of a tracer should be light weight and be able to be called in all contexts. The sched_switch grabbed mutexes in the start/stop functions. This patch changes it to a simple variable, on/off. Signed-off-by: Steven Rostedt

tracing/core: use appropriate waiting on trace_pipe

2009-02-18T00:40:20Z

Impact: api and pipe waiting change Currently, the waiting used in tracing_read_pipe() is done through a 100 msecs schedule_timeout() loop which periodically check if there are traces on the buffer. This can cause small latencies for programs which are reading the incoming events. This patch makes the reader waiting for the trace_wait waitqueue except for few tracers such as the sched and functions tracers which might be already hold the runqueue lock while waking up the reader. This is performed through a new callback wait_pipe() on struct tracer. If none is implemented on a specific tracer, the default waiting for trace_wait queue is attached. Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar