Commit Graph

39 Commits

Author SHA1 Message Date
Steven Rostedt e4a9ea5ee7 tracing: Replace trace_event struct array with pointer array
Currently the trace_event structures are placed in the _ftrace_events
section, and at link time, the linker makes one large array of all
the trace_event structures. On boot up, this array is read (much like
the initcall sections) and the events are processed.

The problem is that there is no guarantee that gcc will place complex
structures nicely together in an array format. Two structures in the
same file may be placed awkwardly, because gcc has no clue that they
are suppose to be in an array.

A hack was used previous to force the alignment to 4, to pack the
structures together. But this caused alignment issues with other
architectures (sparc).

Instead of packing the structures into an array, the structures' addresses
are now put into the _ftrace_event section. As pointers are always the
natural alignment, gcc should always pack them tightly together
(otherwise initcall, extable, etc would also fail).

By having the pointers to the structures in the section, we can still
iterate the trace_events without causing unnecessary alignment problems
with other architectures, or depending on the current behaviour of
gcc that will likely change in the future just to tick us kernel developers
off a little more.

The _ftrace_event section is also moved into the .init.data section
as it is now only needed at boot up.

Suggested-by: David Miller <davem@davemloft.net>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-02 21:37:13 -05:00
Steven Rostedt 0429578016 tracing/events: Show real number in array fields
Currently we have in something like the sched_switch event:

  field:char prev_comm[TASK_COMM_LEN];	offset:12;	size:16;	signed:1;

When a userspace tool such as perf tries to parse this, the
TASK_COMM_LEN is meaningless. This is done because the TRACE_EVENT() macro
simply uses a #len to show the string of the length. When the length is
an enum, we get a string that means nothing for tools.

By adding a static buffer and a mutex to protect it, we can store the
string into that buffer with snprintf and show the actual number.
Now we get:

  field:char prev_comm[16];       offset:12;      size:16;        signed:1;

Something much more useful.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-11-19 10:18:47 -05:00
Li Zefan ffb9f99528 tracing: Remove redundant raw_init callbacks
raw_init callback is optional.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4BFA37D4.7070500@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-06-28 17:12:53 -04:00
Steven Rostedt 32c0edaeaa tracing: Remove duplicate id information in event structure
Now that the trace_event structure is embedded in the ftrace_event_call
structure, there is no need for the ftrace_event_call id field.
The id field is the same as the trace_event type field.

Removing the id and re-arranging the structure brings down the tracepoint
footprint by another 5K.

   text	   data	    bss	    dec	    hex	filename
4913961	1088356	 861512	6863829	 68bbd5	vmlinux.orig
4895024	1023812	 861512	6780348	 6775bc	vmlinux.print
4894944	1018052	 861512	6774508	 675eec	vmlinux.id

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-14 14:33:15 -04:00
Steven Rostedt 0405ab80aa tracing: Move raw_init from events to class
The raw_init function pointer in the event is used to initialize
various kinds of events. The type of initialization needed is usually
classed to the kind of event it is.

Two events with the same class will always have the same initialization
function, so it makes sense to move this to the class structure.

Perhaps even making a special system structure would work since
the initialization is the same for all events within a system.
But since there's no system structure (yet), this will just move it
to the class.

   text	   data	    bss	    dec	    hex	filename
4913961	1088356	 861512	6863829	 68bbd5	vmlinux.orig
4900375	1053380	 861512	6815267	 67fe23	vmlinux.fields
4900382	1048964	 861512	6810858	 67ecea	vmlinux.init

The text grew very slightly, but this is a constant growth that happened
with the changing of the C files that call the init code.
The bigger savings is the data which will be saved the more events share
a class.

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-14 14:20:30 -04:00
Steven Rostedt 2e33af0295 tracing: Move fields from event to class structure
Move the defined fields from the event to the class structure.
Since the fields of the event are defined by the class they belong
to, it makes sense to have the class hold the information instead
of the individual events. The events of the same class would just
hold duplicate information.

After this change the size of the kernel dropped another 3K:

   text	   data	    bss	    dec	    hex	filename
4913961	1088356	 861512	6863829	 68bbd5	vmlinux.orig
4900252	1057412	 861512	6819176	 680d68	vmlinux.regs
4900375	1053380	 861512	6815267	 67fe23	vmlinux.fields

Although the text increased, this was mainly due to the C files
having to adapt to the change. This is a constant increase, where
new tracepoints will not increase the Text. But the big drop is
in the data size (as well as needed allocations to hold the fields).
This will give even more savings as more tracepoints are created.

Note, if just TRACE_EVENT()s are used and not DECLARE_EVENT_CLASS()
with several DEFINE_EVENT()s, then the savings will be lost. But
we are pushing developers to consolidate events with DEFINE_EVENT()
so this should not be an issue.

The kprobes define a unique class to every new event, but are dynamic
so it should not be a issue.

The syscalls however have a single class but the fields for the individual
events are different. The syscalls use a metadata to define the
fields. I moved the fields list from the event to the metadata and
added a "get_fields()" function to the class. This function is used
to find the fields. For normal events and kprobes, get_fields() just
returns a pointer to the fields list_head in the class. For syscall
events, it returns the fields list_head in the metadata for the event.

v2:  Fixed the syscall fields. The syscall metadata needs a list
     of fields for both enter and exit.

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-14 14:20:23 -04:00
Steven Rostedt 8f08201830 tracing: Create class struct for events
This patch creates a ftrace_event_class struct that event structs point to.
This class struct will be made to hold information to modify the
events. Currently the class struct only holds the events system name.

This patch slightly increases the size, but this change lays the ground work
of other changes to make the footprint of tracepoints smaller.

With 82 standard tracepoints, and 618 system call tracepoints
(two tracepoints per syscall: enter and exit):

   text	   data	    bss	    dec	    hex	filename
4913961	1088356	 861512	6863829	 68bbd5	vmlinux.orig
4914025	1088868	 861512	6864405	 68be15	vmlinux.class

This patch also cleans up some stale comments in ftrace.h.

v2: Fixed missing semi-colon in macro.

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-14 09:33:49 -04:00
Lai Jiangshan 0fa0edaf32 tracing: Remove show_format and related macros from TRACE_EVENT
The previous patches added the use of print_fmt string and changes
the trace_define_field() function to also create the fields and
format output for the event format files.

   text	   data	    bss	    dec	    hex	filename
5857201	1355780	9336808	16549789	 fc879d	vmlinux
5884589	1351684	9337896	16574169	 fce6d9	vmlinux-orig

The above shows the size of the vmlinux after this patch set
compared to the vmlinux-orig which is before the patch set.

This saves us 27k on text, 1k on bss and adds just 4k of data.

The total savings of 24k in size.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4B273D4D.40604@cn.fujitsu.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-06 12:08:46 -05:00
Lai Jiangshan 509e760cd9 tracing: Add print_fmt field
This is part of a patch set that removes the show_format method
in the ftrace event macros.

The print_fmt field is added to hold the string that shows
the print_fmt in the event format files. This patch only adds
the field but it is currently not used. Later patches will use
this field to enable us to remove the show_format field
and function.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4B273D3E.2000704@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-06 11:41:54 -05:00
Lai Jiangshan 809826a389 tracing: Have __dynamic_array() define a field
This is part of a patch set that removes the show_format method
in the ftrace event macros.

This patch set requires that all fields are added to the
ftrace_event_call->fields. This patch changes __dynamic_array()
to call trace_define_field() to include fields that use __dynamic_array().

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4B273D36.8090100@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-06 11:30:02 -05:00
Lai Jiangshan fb7ae981cb tracing: Fix sign fields in ftrace_define_fields_##call()
Add is_signed_type() call to trace_define_field() in ftrace macros.

The code previously just passed in 0 (false), disregarding whether
or not the field was actually a signed type.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4B273D3A.6020007@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-12-30 10:27:06 -05:00
Li Zefan 614a71a26b tracing: Pull up calls to trace_define_common_fields()
Call trace_define_common_fields() in event_create_dir() only.
This avoids trace events to handle it from their define_fields
callbacks and shrinks the kernel code size:

   text    data     bss     dec     hex filename
5346802 1961864 7103260 14411926         dbe896 vmlinux.o.old
5345151 1961864 7103260 14410275         dbe223 vmlinux.o

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
LKML-Reference: <4B1DC49C.8000107@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-12-13 18:34:23 +01:00
Linus Torvalds c3fa27d136 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (470 commits)
  x86: Fix comments of register/stack access functions
  perf tools: Replace %m with %a in sscanf
  hw-breakpoints: Keep track of user disabled breakpoints
  tracing/syscalls: Make syscall events print callbacks static
  tracing: Add DEFINE_EVENT(), DEFINE_SINGLE_EVENT() support to docbook
  perf: Don't free perf_mmap_data until work has been done
  perf_event: Fix compile error
  perf tools: Fix _GNU_SOURCE macro related strndup() build error
  trace_syscalls: Remove unused syscall_name_to_nr()
  trace_syscalls: Simplify syscall profile
  trace_syscalls: Remove duplicate init_enter_##sname()
  trace_syscalls: Add syscall_nr field to struct syscall_metadata
  trace_syscalls: Remove enter_id exit_id
  trace_syscalls: Set event_enter_##sname->data to its metadata
  trace_syscalls: Remove unused event_syscall_enter and event_syscall_exit
  perf_event: Initialize data.period in perf_swevent_hrtimer()
  perf probe: Simplify event naming
  perf probe: Add --list option for listing current probe events
  perf probe: Add argv_split() from lib/argv_split.c
  perf probe: Move probe event utility functions to probe-event.c
  ...
2009-12-05 15:30:21 -08:00
Li Zefan 5e9b397292 tracing: Fix to use __always_unused attribute
____ftrace_check_##name() is used for compile-time check on
F_printk() only, so it should be marked as __unused instead
of __used.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <4AEE2D01.4010305@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-02 15:47:54 +01:00
Ingo Molnar 4331595650 Merge branch 'perf/core' into perf/probes
Conflicts:
	tools/perf/Makefile

Merge reason:

 - fix the conflict
 - pick up the pr_*() infrastructure to queue up dependent patch

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-23 08:23:20 +02:00
Tom Zanussi 26a50744b2 tracing/events: Add 'signed' field to format files
The sign info used for filters in the kernel is also useful to
applications that process the trace stream.  Add it to the format
files and make it available to userspace.

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: rostedt@goodmis.org
Cc: lizf@cn.fujitsu.com
Cc: hch@infradead.org
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <1254809398-8078-2-git-send-email-tzanussi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-06 15:04:45 +02:00
Frederic Weisbecker d7a4b414ee Merge commit 'linus/master' into tracing/kprobes
Conflicts:
	kernel/trace/Makefile
	kernel/trace/trace.h
	kernel/trace/trace_event_types.h
	kernel/trace/trace_export.c

Merge reason:
	Sync with latest significant tracing core changes.
2009-09-23 23:08:43 +02:00
Li Zefan 20a58a7723 tracing: remove some unused macros
- remove FTRACE_ENTRY_STRUCT_ONLY()
- remove TRACE_XXX() macros

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4AADF6E6.3080606@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-14 11:43:24 -04:00
Li Zefan 05ffa2d020 ftrace: add compile-time check on F_printk()
Make sure F_printk() has corrent format and args, and make sure
changes in F_STRUCT() won't break F_printk().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4AADF6CC.1060809@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-14 11:42:10 -04:00
Steven Rostedt 4e5292ea1a tracing: use the new trace_entries.h to create format files
This patch changes the way the format files in

  debugfs/tracing/events/ftrace/*/format

are created. It uses the new trace_entries.h file to automate the
creation of the format files to ensure that they are always in sync
with the actual structures. This is the same methodology used to
create the format files for the TRACE_EVENT macro.

This also updates the filter creation that was built on the creation
of the format files.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-12 23:08:10 -04:00
Frederic Weisbecker 8f8ffe2485 Merge commit 'tracing/core' into tracing/kprobes
Conflicts:
	kernel/trace/trace_export.c
	kernel/trace/trace_kprobe.c

Merge reason: This topic branch lacks an important
build fix in tracing/core:

	0dd7b74787eaf7858c6c573353a83c3e2766e674:
	tracing: Fix double CPP substitution in TRACE_EVENT_FN

that prevents from multiple tracepoint headers inclusion crashes.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-11 01:09:23 +02:00
Li Zefan 8e254c1d18 tracing/filters: Defer pred allocation
init_preds() allocates about 5392 bytes of memory (on x86_32) for
a TRACE_EVENT. With my config, at system boot total memory occupied
is:

	5392 * (642 + 15) == 3459KB

642 == cat available_events | wc -l
15 == number of dirs in events/ftrace

That's quite a lot, so we'd better defer memory allocation util
it's needed, that's when filter is used.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
LKML-Reference: <4A9B8EA5.6020700@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-31 10:58:08 +02:00
Masami Hiramatsu d93f12f3f4 tracing: Introduce TRACE_FIELD_ZERO() macro
Use TRACE_FIELD_ZERO(type, item) instead of TRACE_FIELD_ZERO_CHAR(item).
This also includes a typo fix of TRACE_ZERO_CHAR() macro.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Przemysław Pawełczyk <przemyslaw@pawelczyk.it>
Cc: Roland McGrath <roland@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
LKML-Reference: <20090813203501.31965.30172.stgit@localhost.localdomain>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-08-27 00:46:40 +02:00
Masami Hiramatsu bd1a5c849b tracing: Ftrace dynamic ftrace_event_call support
Add dynamic ftrace_event_call support to ftrace. Trace engines can add
new ftrace_event_call to ftrace on the fly. Each operator function of
the call takes an ftrace_event_call data structure as an argument,
because these functions may be shared among several ftrace_event_calls.

Changes from v13:
 - Define remove_subsystem_dir() always (revirt a2ca5e03), because
   trace_remove_event_call() uses it.
 - Modify syscall tracer because of ftrace_event_call change.

[fweisbec@gmail.com: Fixed conflict against latest tracing/core]

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Przemysław Pawełczyk <przemyslaw@pawelczyk.it>
Cc: Roland McGrath <roland@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
LKML-Reference: <20090813203453.31965.71901.stgit@localhost.localdomain>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-08-27 00:46:40 +02:00
Li Zefan 43b51ead3f tracing/filters: Add __field_ext() to TRACE_EVENT
Add __field_ext(), so a field can be assigned to a specific
filter_type, which matches a corresponding filter function.

For example, a later patch will allow this:
	__field_ext(const char *, str, FILTER_PTR_STR);

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4A7B9272.6050709@cn.fujitsu.com>

[
  Fixed a -1 to FILTER_OTHER
  Forward ported to latest kernel.
]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-08-26 00:32:06 -04:00
Li Zefan e647d6b314 tracing/events: Add trace_define_common_fields()
Extract duplicate code. Also prepare for the later patch.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A8BAFB8.1010304@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-19 15:02:24 +02:00
Li Zefan 14be96c971 tracing/events: Add ftrace_event_call param to define_fields()
This parameter is needed by syscall events to add define_fields()
handler.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A8BAF90.6060801@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-19 15:02:23 +02:00
Frederic Weisbecker e8f9f4d79a tracing: Add ftrace event call parameter to its field descriptor handler
Add the struct ftrace_event_call as a parameter of its show_format()
callback. This way we can use it from the syscall trace events to
retrieve the syscall name from the ftrace event call parameter and
describe its fields using the syscalls metadata.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jiaying Zhang <jiayingz@google.com>
Cc: Martin Bligh <mbligh@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
2009-08-11 20:35:29 +02:00
Tom Zanussi a118e4d140 tracing/filters: distinguish between signed and unsigned fields
The new filter comparison ops need to be able to distinguish between
signed and unsigned field types, so add an is_signed flag/param to the
event field struct/trace_define_fields().  Also define a simple macro,
is_signed_type() to determine the signedness at compile time, used in the
trace macros.  If the is_signed_type() macro won't work with a specific
type, a new slightly modified version of TRACE_FIELD() called
TRACE_FIELD_SIGN(), allows the signedness to be set explicitly.

[ Impact: extend trace-filter code for new feature ]

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: fweisbec@gmail.com
Cc: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <1240905893.6416.120.camel@tropicana>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-29 14:06:03 +02:00
Steven Rostedt 75db37d2f4 tracing: add size checks for exported ftrace internal structures
The events exported by TRACE_EVENT are automated and are guaranteed
to be correct when used.

The internal ftrace structures on the other hand are more manually
exported. These require the ftrace maintainer to make sure they
are up to date.

This patch adds a size check to help flag when a type changes in
an internal ftrace data structure, and the update needs to be reflected
in the export.

If a export is incorrect, then the only harm is that the user space
tools will not know how to correctly read the internal structures of
ftrace.

[ Impact: help prevent inconsistent ftrace format print outs ]

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-04-23 23:03:56 -04:00
Tom Zanussi 0a19e53c15 tracing/filters: allow on-the-fly filter switching
This patch allows event filters to be safely removed or switched
on-the-fly while avoiding the use of rcu or the suspension of tracing of
previous versions.

It does it by adding a new filter_pred_none() predicate function which
does nothing and by never deallocating either the predicates or any of
the filter_pred members used in matching; the predicate lists are
allocated and initialized during ftrace_event_calls initialization.

Whenever a filter is removed or replaced, the filter_pred_* functions
currently in use by the affected ftrace_event_call are immediately
switched over to to the filter_pred_none() function, while the rest of
the filter_pred members are left intact, allowing any currently
executing filter_pred_* functions to finish up, using the values they're
currently using.

In the case of filter replacement, the new predicate values are copied
into the old predicates after the above step, and the filter_pred_none()
functions are replaced by the filter_pred_* functions for the new
filter.  In this case, it is possible though very unlikely that a
previous filter_pred_* is still running even after the
filter_pred_none() switch and the switch to the new filter_pred_*.  In
that case, however, because nothing has been deallocated in the
filter_pred, the worst that can happen is that the old filter_pred_*
function sees the new values and as a result produces either a false
positive or a false negative, depending on the values it finds.

So one downside to this method is that rarely, it can produce a bad
match during the filter switch, but it should be possible to live with
that, IMHO.

The other downside is that at least in this patch the predicate lists
are always pre-allocated, taking up memory from the start.  They could
probably be allocated on first-use, and de-allocated when tracing is
completely stopped - if this patch makes sense, I could create another
one to do that later on.

Oh, and it also places a restriction on the size of __arrays in events,
currently set to 128, since they can't be larger than the now embedded
str_val arrays in the filter_pred struct.

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: paulmck@linux.vnet.ibm.com
LKML-Reference: <1239610670.6660.49.camel@tropicana>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 00:03:55 +02:00
Tom Zanussi e45f2e2bd2 tracing/filters: add TRACE_EVENT_FORMAT_NOFILTER event macro
Frederic Weisbecker suggested that the trace_special event shouldn't be
filterable; this patch adds a TRACE_EVENT_FORMAT_NOFILTER event macro
that allows an event format to be exported without having a filter
attached, and removes filtering from the trace_special event.

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 00:00:51 +02:00
Tom Zanussi e1112b4d96 tracing/filters: add run-time field descriptions to TRACE_EVENT_FORMAT events
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 <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 00:00:50 +02:00
Zhaolei 1bbe2a83ab ftrace: Correct a text align for event format output
If we cat debugfs/tracing/events/ftrace/bprint/format, we'll see:
name: bprint
ID: 6
format:
	field:unsigned char common_type;	offset:0;	size:1;
	field:unsigned char common_flags;	offset:1;	size:1;
	field:unsigned char common_preempt_count;	offset:2;	size:1;
	field:int common_pid;	offset:4;	size:4;
	field:int common_tgid;	offset:8;	size:4;

	field:unsigned long ip;	offset:12;	size:4;
	field:char * fmt;	offset:16;	size:4;
	field: char buf;	offset:20;	size:0;

print fmt: "%08lx (%d) fmt:%p %s"

There is an inconsistent blank before char buf.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
LKML-Reference: <49D5E3EE.70201@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-07 14:02:42 +02:00
Steven Rostedt ef18012b24 tracing: remove funky whitespace in the trace code
Impact: clean up

There existed a lot of <space><tab>'s in the tracing code. This
patch removes them.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 14:13:14 -04:00
Steven Rostedt da4d03020c tracing: new format for specialized trace points
Impact: clean up and enhancement

The TRACE_EVENT_FORMAT macro looks quite ugly and is limited in its
ability to save data as well as to print the record out. Working with
Ingo Molnar, we came up with a new format that is much more pleasing to
the eye of C developers. This new macro is more C style than the old
macro, and is more obvious to what it does.

Here's the example. The only updated macro in this patch is the
sched_switch trace point.

The old method looked like this:

 TRACE_EVENT_FORMAT(sched_switch,
        TP_PROTO(struct rq *rq, struct task_struct *prev,
                struct task_struct *next),
        TP_ARGS(rq, prev, next),
        TP_FMT("task %s:%d ==> %s:%d",
              prev->comm, prev->pid, next->comm, next->pid),
        TRACE_STRUCT(
                TRACE_FIELD(pid_t, prev_pid, prev->pid)
                TRACE_FIELD(int, prev_prio, prev->prio)
                TRACE_FIELD_SPECIAL(char next_comm[TASK_COMM_LEN],
                                    next_comm,
                                    TP_CMD(memcpy(TRACE_ENTRY->next_comm,
                                                 next->comm,
                                                 TASK_COMM_LEN)))
                TRACE_FIELD(pid_t, next_pid, next->pid)
                TRACE_FIELD(int, next_prio, next->prio)
        ),
        TP_RAW_FMT("prev %d:%d ==> next %s:%d:%d")
        );

The above method is hard to read and requires two format fields.

The new method:

 /*
  * Tracepoint for task switches, performed by the scheduler:
  *
  * (NOTE: the 'rq' argument is not used by generic trace events,
  *        but used by the latency tracer plugin. )
  */
 TRACE_EVENT(sched_switch,

	TP_PROTO(struct rq *rq, struct task_struct *prev,
		 struct task_struct *next),

	TP_ARGS(rq, prev, next),

	TP_STRUCT__entry(
		__array(	char,	prev_comm,	TASK_COMM_LEN	)
		__field(	pid_t,	prev_pid			)
		__field(	int,	prev_prio			)
		__array(	char,	next_comm,	TASK_COMM_LEN	)
		__field(	pid_t,	next_pid			)
		__field(	int,	next_prio			)
	),

	TP_printk("task %s:%d [%d] ==> %s:%d [%d]",
		__entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
		__entry->next_comm, __entry->next_pid, __entry->next_prio),

	TP_fast_assign(
		memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
		__entry->prev_pid	= prev->pid;
		__entry->prev_prio	= prev->prio;
		memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
		__entry->next_pid	= next->pid;
		__entry->next_prio	= next->prio;
	)
 );

This macro is called TRACE_EVENT, it is broken up into 5 parts:

 TP_PROTO:        the proto type of the trace point
 TP_ARGS:         the arguments of the trace point
 TP_STRUCT_entry: the structure layout of the entry in the ring buffer
 TP_printk:       the printk format
 TP_fast_assign:  the method used to write the entry into the ring buffer

The structure is the definition of how the event will be saved in the
ring buffer. The printk is used by the internal tracing in case of
an oops, and the kernel needs to print out the format of the record
to the console. This the TP_printk gives a means to show the records
in a human readable format. It is also used to print out the data
from the trace file.

The TP_fast_assign is executed directly. It is basically like a C function,
where the __entry is the handle to the record.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 00:35:07 -04:00
Steven Rostedt 2939b0469d tracing: replace TP<var> with TP_<var>
Impact: clean up

The macros TPPROTO, TPARGS, TPFMT, TPRAWFMT, and TPCMD all look a bit
ugly. This patch adds an underscore to their names.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 00:35:04 -04:00
Steven Rostedt 156b5f172a tracing: typecast sizeof and offsetof to unsigned int
Impact: fix compiler warnings

On x86_64 sizeof and offsetof are treated as long, where as on x86_32
they are int. This patch typecasts them to unsigned int to avoid
one arch giving warnings while the other does not.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 00:34:03 -04:00
Steven Rostedt 770cb24345 tracing: add format files for ftrace default entries
Impact: allow user apps to read binary format of basic ftrace entries

Currently, only defined raw events export their formats so a binary
reader can parse them. There's no reason that the default ftrace entries
can't export their formats.

This patch adds a subsystem called "ftrace" in the events directory
that includes the ftrace entries for basic ftrace recorded items.

These only have three files in the events directory:

 type             : printf
 available_types  : printf
 format           : format for the event entry

For example:

 # cat /debug/tracing/events/ftrace/wakeup/format
name: wakeup
ID: 3
format:
        field:unsigned char type;       offset:0;       size:1;
        field:unsigned char flags;      offset:1;       size:1;
        field:unsigned char preempt_count;      offset:2;       size:1;
        field:int pid;  offset:4;       size:4;
        field:int tgid; offset:8;       size:4;

        field:unsigned int prev_pid;    offset:12;      size:4;
        field:unsigned char prev_prio;  offset:16;      size:1;
        field:unsigned char prev_state; offset:17;      size:1;
        field:unsigned int next_pid;    offset:20;      size:4;
        field:unsigned char next_prio;  offset:24;      size:1;
        field:unsigned char next_state; offset:25;      size:1;
        field:unsigned int next_cpu;    offset:28;      size:4;

print fmt: "%u:%u:%u  ==+ %u:%u:%u [%03u]"

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-05 21:46:44 -05:00