linux/kernel/trace/kmemtrace.c, branch v2.6.35

tracing: Allow events to share their print functions

2010-05-14T18:20:32Z

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

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

kmemtrace: Fix up tracer registration

2009-10-01T09:53:44Z

Commit ddc1637af217dbd8bc51f30e6d24e84476a869a6 ("kmemtrace: Print binary output only if 'bin' option is set") ended up inverting the error detection logic. register_tracer() returns 0 on success, which this change caused to treat as an error, resulting in: [ 0.132000] Warning: could not register the kmem tracer as well as bailing out of the initcall with an error value. This restores the old logic. Signed-off-by: Paul Mundt Acked-by: Pekka Enberg Acked-by: Frederic Weisbecker Cc: Eduard - Gabriel Munteanu Cc: Steven Rostedt Cc: Li Zefan LKML-Reference: <20090928075540.GD6668@linux-sh.org> Signed-off-by: Ingo Molnar

tracing: remove users of tracing_reset

2009-09-04T16:12:39Z

The function tracing_reset is deprecated for outside use of trace.c. The new function to reset the the buffers is tracing_reset_online_cpus. The reason for this is that resetting the buffers while the event trace points are active can corrupt the buffers, because they may be writing at the time of reset. The tracing_reset_online_cpus disables writes and waits for current writers to finish. This patch replaces all users of tracing_reset except for the latency tracers. Those changes require more work and will be removed in the following patches. Signed-off-by: Steven Rostedt

kmemtrace: Rename some functions

2009-07-10T10:09:04Z

So we have: - kmemtrace_print_alloc/free() for kmemtrace default output - kmemtrace_print_alloc/free_user() for binary output used by kmemtrace-user. Suggested-by: Eduard - Gabriel Munteanu Signed-off-by: Li Zefan Acked-by: Pekka Enberg Cc: Steven Rostedt Cc: Frederic Weisbecker LKML-Reference: <4A51B288.70505@cn.fujitsu.com> Signed-off-by: Ingo Molnar

tracing/kmemtrace: Use the %pf format

2009-07-10T10:07:20Z

Remove the obsolete seq_print_ip_sym() usage and replace it by the %pf format in order to print function symbols. Signed-off-by: Frederic Weisbecker Reviewed-by: Li Zefan Cc: Steven Rostedt Cc: Lai Jiangshan Cc: Pekka Enberg Cc: Eduard - Gabriel Munteanu LKML-Reference: <1247107590-6428-3-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar

kmemtrace: Print binary output only if 'bin' option is set

2009-07-03T09:39:46Z

Currently by default the output of kmemtrace is binary format instead of human-readable output. This patch makes the following changes: - We'll see human-readable output by default - We'll see binary output if 'bin' option is set Note: you may probably need to explicitly disable context-info binary output: # echo 0 > options/context-info # echo 1 > options/bin # cat trace_pipe v2: - use %pF to print call_site Signed-off-by: Li Zefan Acked-by: Pekka Enberg Acked-by: Eduard - Gabriel Munteanu Cc: Steven Rostedt Cc: Frederic Weisbecker LKML-Reference: <4A4DD0A0.5060500@cn.fujitsu.com> Signed-off-by: Ingo Molnar

cpumask: use new operators in kernel/trace

2009-06-15T15:36:42Z

Signed-off-by: Rusty Russell LKML-Reference: <200906122115.30787.rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt

tracing/filters: use ring_buffer_discard_commit() in filter_check_discard()

2009-04-13T22:00:56Z

This patch changes filter_check_discard() to make use of the new ring_buffer_discard_commit() function and modifies the current users to call the old commit function in the non-discard case. It also introduces a version of filter_check_discard() that uses the global trace buffer (filter_current_check_discard()) for those cases. v2 changes: - fix compile error noticed by Ingo Molnar Signed-off-by: Tom Zanussi Cc: Steven Rostedt Cc: fweisbec@gmail.com LKML-Reference: <1239178554.10295.36.camel@tropicana> Signed-off-by: Ingo Molnar

tracing/filters: add run-time field descriptions to TRACE_EVENT_FORMAT events

2009-04-13T22:00:50Z

This patch adds run-time field descriptions to all the event formats exported using TRACE_EVENT_FORMAT. It also hooks up all the tracers that use them (i.e. the tracers in the 'ftrace subsystem') so they can also have their output filtered by the event-filtering mechanism. When I was testing this, there were a couple of things that fooled me into thinking the filters weren't working, when actually they were - I'll mention them here so others don't make the same mistakes (and file bug reports. ;-) One is that some of the tracers trace multiple events e.g. the sched_switch tracer uses the context_switch and wakeup events, and if you don't set filters on all of the traced events, the unfiltered output from the events without filters on them can make it look like the filtering as a whole isn't working properly, when actually it is doing what it was asked to do - it just wasn't asked to do the right thing. The other is that for the really high-volume tracers e.g. the function tracer, the volume of filtered events can be so high that it pushes the unfiltered events out of the ring buffer before they can be read so e.g. cat'ing the trace file repeatedly shows either no output, or once in awhile some output but that isn't there the next time you read the trace, which isn't what you normally expect when reading the trace file. If you read from the trace_pipe file though, you can catch them before they disappear. Changes from v1: As suggested by Frederic Weisbecker: - get rid of externs in functions - added unlikely() to filter_check_discard() Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar