linux/include/trace/define_trace.h, branch v3.1-rc8

tracing: Include module.h in define_trace.h

2011-01-07T20:44:56Z

While doing some developing, Peter Zijlstra and I have found that if a CREATE_TRACE_POINTS include is done before module.h is included, it can break the build. We have been lucky so far that this has not broke the build since module.h is included in almost everything. Reported-by: Peter Zijlstra Signed-off-by: Steven Rostedt

tracing: Add TRACE_EVENT_CONDITIONAL()

2010-12-03T15:45:34Z

There are instances in the kernel that we only want to trace a tracepoint when a certain condition is set. But we do not want to test for that condition in the core kernel. If we test for that condition before calling the tracepoin, then we will be performing that test even when tracing is not enabled. This is 99.99% of the time. We currently can just filter out on that condition, but that happens after we write to the trace buffer. We just wasted time writing to the ring buffer for an event we never cared about. This patch adds: TRACE_EVENT_CONDITION() and DEFINE_EVENT_CONDITION() These have a new TP_CONDITION() argument that comes right after the TP_ARGS(). This condition can use the parameters of TP_ARGS() in the TRACE_EVENT() to determine if the tracepoint should be traced or not. The TP_CONDITION() will be placed in a if (cond) trace; For example, for the tracepoint sched_wakeup, it is useless to trace a wakeup event where the caller never actually wakes anything up (where success == 0). So adding: TP_CONDITION(success), which uses the "success" parameter of the wakeup tracepoint will have it only trace when we have successfully woken up a task. Acked-by: Mathieu Desnoyers Acked-by: Frederic Weisbecker Cc: Arjan van de Ven Cc: Thomas Gleixner Signed-off-by: Steven Rostedt

tracing: Fix tracepoint.h DECLARE_TRACE() to allow more than one header

2010-05-05T15:46:17Z

When more than one header is included under CREATE_TRACE_POINTS the DECLARE_TRACE() macro is not defined back to its original meaning and the second include will fail to initialize the TRACE_EVENT() and DECLARE_TRACE() correctly. To fix this the tracepoint.h file moves the define of DECLARE_TRACE() out of the #ifdef _LINUX_TRACEPOINT_H protection (just like the define of the TRACE_EVENT()). This way the define_trace.h will undef the DECLARE_TRACE() at the end and allow new headers to start from scratch. This patch also requires fixing the include/events/napi.h It currently uses DECLARE_TRACE() and should be converted to a TRACE_EVENT() format. But I'll leave that change to the authors of that file. But since the napi.h file depends on using the CREATE_TRACE_POINTS and does not define its own DEFINE_TRACE() it must use the define_trace.h method instead. Cc: Neil Horman Cc: David S. Miller Cc: Mathieu Desnoyers Signed-off-by: Steven Rostedt

events: Rename TRACE_EVENT_TEMPLATE() to DECLARE_EVENT_CLASS()

2009-11-26T08:04:55Z

It is not quite obvious at first sight what TRACE_EVENT_TEMPLATE does: does it define an event as well beyond defining a template? To clarify this, rename it to DECLARE_EVENT_CLASS, which follows the various 'DECLARE_*()' idioms we already have in the kernel: DECLARE_EVENT_CLASS(class) DEFINE_EVENT(class, event1) DEFINE_EVENT(class, event2) DEFINE_EVENT(class, event3) To complete this logic we should also rename TRACE_EVENT() to: DEFINE_SINGLE_EVENT(single_event) ... but in a more quiet moment of the kernel cycle. Cc: Pekka Enberg Cc: Steven Rostedt Cc: Frederic Weisbecker LKML-Reference: <4B0E286A.2000405@cn.fujitsu.com> Signed-off-by: Ingo Molnar

tracing: Create new DEFINE_EVENT_PRINT

2009-11-24T23:23:53Z

After creating the TRACE_EVENT_TEMPLATE I started to look at other trace points to see what duplication was made. I noticed that there are several trace points where they are almost identical except for the name and the output format. Since TRACE_EVENT_TEMPLATE was successful in bringing down the size of trace events, I added a DEFINE_EVENT_PRINT. DEFINE_EVENT_PRINT is used just like DEFINE_EVENT is. That is, the DEFINE_EVENT_PRINT also uses a TRACE_EVENT_TEMPLATE, but it allows the developer to overwrite the print format. If there are two or more TRACE_EVENTS that are identical except for the name and print, then they can be converted to use a TRACE_EVENT_TEMPLATE. Since the TRACE_EVENT_TEMPLATE already does the print output, the first trace event would have its print format held in the TRACE_EVENT_TEMPLATE and be defined with a DEFINE_EVENT. The rest will use the DEFINE_EVENT_PRINT and override the print format. Converting the sched trace points to both DEFINE_EVENT and DEFINE_EVENT_PRINT. Five were converted to DEFINE_EVENT and two were converted to DEFINE_EVENT_PRINT. I was able to get the following: $ size kernel/sched.o-* text data bss dec hex filename 79299 6776 2520 88595 15a13 kernel/sched.o-notrace 101941 11896 2584 116421 1c6c5 kernel/sched.o-templ 104779 11896 2584 119259 1d1db kernel/sched.o-trace sched.o-notrace is the scheduler compiled with no trace points. sched.o-templ is with the use of DEFINE_EVENT and DEFINE_EVENT_PRINT sched.o-trace is the current trace events. Signed-off-by: Steven Rostedt

tracing: Create new TRACE_EVENT_TEMPLATE

2009-11-24T22:52:11Z

There are some places in the kernel that define several tracepoints and they are all identical besides the name. The code to enable, disable and record is created for every trace point even if most of the code is identical. This patch adds TRACE_EVENT_TEMPLATE that lets the developer create a template TRACE_EVENT and create trace points with DEFINE_EVENT, which is based off of a given template. Each trace point used by this will share most of the code, and bring down the size of the kernel when there are several duplicate events. Usage is: TRACE_EVENT_TEMPLATE(name, proto, args, tstruct, assign, print); Which would be the same as defining a normal TRACE_EVENT. To create the trace events that the trace points will use: DEFINE_EVENT(template, name, proto, args) is done. The template is the name of the TRACE_EVENT_TEMPLATE to use. The name is the name of the trace point. The parameters proto and args must be the same as the proto and args of the template. If they are not the same, then a compile error will result. I tried hard removing this duplication but the C preprocessor is not powerful enough (or my CPP magic experience points is not at a high enough level) to not need them. A lot of trace events are coming in with new XFS development. Most of the trace points are identical except for the name. The following shows the advantage of having TRACE_EVENT_TEMPLATE: $ size fs/xfs/xfs.o.* text data bss dec hex filename 452114 2788 3520 458422 6feb6 fs/xfs/xfs.o.old 638482 38116 3744 680342 a6196 fs/xfs/xfs.o.template 996954 38116 4480 1039550 fdcbe fs/xfs/xfs.o.trace xfs.o.old is without any tracepoints. xfs.o.template uses the new TRACE_EVENT_TEMPLATE. xfs.o.trace uses the current TRACE_EVENT macros. Requested-by: Christoph Hellwig Signed-off-by: Steven Rostedt

tracing: Undef TRACE_EVENT_FN between trace events headers inclusion

2009-08-27T16:32:54Z

The recent commit: tracing/events: fix the include file dependencies fixed a file dependency problem while including more than one trace event header file. This fix undefined TRACE_EVENT after an event header macro preprocessing in order to make tracepoint.h able to correctly declare the tracepoints necessary for the next event header file. But now we also need to undefine TRACE_EVENT_FN at the end of an event header file preprocessing for the same reason. This fixes the following build error: In file included from include/trace/events/napi.h:5, from net/core/net-traces.c:28: include/linux/tracepoint.h:285:1: warning: "TRACE_EVENT_FN" redefined In file included from include/trace/define_trace.h:61, from include/trace/events/skb.h:40, from net/core/net-traces.c:27: include/trace/ftrace.h:50:1: warning: this is the location of the previous definition In file included from include/trace/events/napi.h:5, from net/core/net-traces.c:28: include/linux/tracepoint.h:285:1: warning: "TRACE_EVENT_FN" redefined In file included from include/trace/define_trace.h:61, from include/trace/events/skb.h:40, from net/core/net-traces.c:27: include/trace/ftrace.h:50:1: warning: this is the location of the previous definition Reported-by: Ingo Molnar Signed-off-by: Frederic Weisbecker Cc: Masami Hiramatsu Cc: Xiao Guangrong Cc: Steven Rostedt Cc: Li Zefan LKML-Reference: <20090827161732.GA7618@nowhere> Signed-off-by: Ingo Molnar

Merge branch 'tracing/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into tracing/core

2009-08-26T06:29:02Z

Conflicts: include/linux/tracepoint.h Signed-off-by: Ingo Molnar

tracing/events: fix the include file dependencies

2009-08-26T04:32:09Z

The TRACE_EVENT depends on the include/linux/tracepoint.h first and include/trace/ftrace.h later, if we include the ftrace.h early, a building error will occur. Both define TRACE_EVENT in trace_a.h and trace_b.h, if we include those in .c file, like this: #define CREATE_TRACE_POINTS include include The above will not work, because the TRACE_EVENT was re-defined by the previous .h file. Reported-by: Wei Yongjun Signed-off-by: Xiao Guangrong LKML-Reference: <4A937F5E.3020802@cn.fujitsu.com> Signed-off-by: Steven Rostedt

tracing: Move tracepoint callbacks from declaration to definition

2009-08-25T22:36:41Z

It's not strictly correct for the tracepoint reg/unreg callbacks to occur when a client is hooking up, because the actual tracepoint may not be present yet. This happens to be fine for syscall, since that's in the core kernel, but it would cause problems for tracepoints defined in a module that hasn't been loaded yet. It also means the reg/unreg has to be EXPORTed for any modules to use the tracepoint (as in SystemTap). This patch removes DECLARE_TRACE_WITH_CALLBACK, and instead introduces DEFINE_TRACE_FN which stores the callbacks in struct tracepoint. The callbacks are used now when the active state of the tracepoint changes in set_tracepoint & disable_tracepoint. This also introduces TRACE_EVENT_FN, so ftrace events can also provide registration callbacks if needed. Signed-off-by: Josh Stone Cc: Jason Baron Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Li Zefan Cc: Steven Rostedt Cc: Peter Zijlstra Cc: Mathieu Desnoyers Cc: Jiaying Zhang Cc: Martin Bligh Cc: Lai Jiangshan Cc: Paul Mundt Cc: Martin Schwidefsky Cc: Heiko Carstens LKML-Reference: <1251150194-1713-4-git-send-email-jistone@redhat.com> Signed-off-by: Frederic Weisbecker