linux-toradex.git/kernel/trace/trace_event_perf.c, branch imx-android-r10.4

perf/tracing: Fix regression of perf losing kprobe events

2010-06-11T00:56:54+00:00

With the addition of the code to shrink the kernel tracepoint
infrastructure, we lost kprobes being traced by perf. The reason
is that I tested if the "tp_event->class->perf_probe" existed before
enabling it. This prevents "ftrace only" events (like the function
trace events) from being enabled by perf.

Unfortunately, kprobe events do not use perf_probe. This causes
kprobes to be missed by perf. To fix this, we add the test to
see if "tp_event->class->reg" exists as well as perf_probe.

Normal trace events have only "perf_probe" but no "reg" function,
and kprobes and syscalls have the "reg" but no "perf_probe".
The ftrace unique events do not have either, so this is a valid
test. If a kprobe or syscall is not to be probed by perf, the
"reg" function is called anyway, and will return a failure and
prevent perf from probing it.

Reported-by: Srikar Dronamraju 
Tested-by: Srikar Dronamraju 
Acked-by: Peter Zijlstra 
Signed-off-by: Steven Rostedt

perf_events, trace: Fix perf_trace_destroy(), mutex went missing

2010-05-31T06:46:09+00:00

Steve spotted I forgot to do the destroy under event_mutex.

Reported-by: Steven Rostedt 
Signed-off-by: Peter Zijlstra 
LKML-Reference: <1274451913.1674.1707.camel@laptop>
Signed-off-by: Ingo Molnar

perf_events, trace: Fix probe unregister race

2010-05-31T06:46:09+00:00

tracepoint_probe_unregister() does not synchronize against the probe
callbacks, so do that explicitly. This properly serializes the callbacks
and the free of the data used therein.

Also, use this_cpu_ptr() where possible.

Acked-by: Frederic Weisbecker 
Signed-off-by: Peter Zijlstra 
LKML-Reference: <1274438476.1674.1702.camel@laptop>
Signed-off-by: Ingo Molnar

perf, trace: Fix !x86 build bug

2010-05-25T09:28:49+00:00

Patch b7e2ecef92 (perf, trace: Optimize tracepoints by removing
IRQ-disable from perf/tracepoint interaction) made the
unfortunate mistake of assuming the world is x86 only, correct
this.

The problem was that perf_fetch_caller_regs() did
local_save_flags() into regs->flags, and I re-used that to
remove another local_save_flags(), forgetting !x86 doesn't have
regs->flags.

Do the reverse, remove the local_save_flags() from
perf_fetch_caller_regs() and let the ftrace site do the
local_save_flags() instead.

Signed-off-by: Peter Zijlstra 
Acked-by: Paul Mackerras 
Cc: acme@redhat.com
Cc: efault@gmx.de
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
LKML-Reference: <1274778175.5882.623.camel@twins>
Signed-off-by: Ingo Molnar

Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip into trace/tip/tracing/core-7

2010-05-21T15:49:57+00:00

Conflicts:
	include/linux/ftrace_event.h
	include/trace/ftrace.h
	kernel/trace/trace_event_perf.c
	kernel/trace/trace_kprobe.c
	kernel/trace/trace_syscalls.c

Signed-off-by: Steven Rostedt

perf, trace: Optimize tracepoints by using per-tracepoint-per-cpu hlist to track events

2010-05-21T09:37:56+00:00

Avoid the swevent hash-table by using per-tracepoint
hlists.

Also, avoid conditionals on the fast path by ordering
with probe unregister so that we should never get on
the callback path without the data being there.

Signed-off-by: Peter Zijlstra 
Cc: Arnaldo Carvalho de Melo 
Cc: Frederic Weisbecker 
Cc: Paul Mackerras 
Cc: Mike Galbraith 
Cc: Steven Rostedt 
LKML-Reference: <20100521090710.473188012@chello.nl>
Signed-off-by: Ingo Molnar

perf, trace: Optimize tracepoints by removing IRQ-disable from perf/tracepoint interaction

2010-05-21T09:37:56+00:00

Improves performance.

Acked-by: Frederic Weisbecker 
Signed-off-by: Peter Zijlstra 
Cc: Arnaldo Carvalho de Melo 
Cc: Frederic Weisbecker 
Cc: Paul Mackerras 
Cc: Mike Galbraith 
Cc: Steven Rostedt 
LKML-Reference: <1274259525.5605.10352.camel@twins>
Signed-off-by: Ingo Molnar

perf/ftrace: Optimize perf/tracepoint interaction for single events

2010-05-18T16:35:46+00:00

When we've got but a single event per tracepoint
there is no reason to try and multiplex it so don't.

Signed-off-by: Peter Zijlstra 
Tested-by: Ingo Molnar 
Cc: Steven Rostedt 
Cc: Frederic Weisbecker 
Cc: Mike Galbraith 
Cc: Paul Mackerras 
Cc: Arnaldo Carvalho de Melo 
LKML-Reference: 
Signed-off-by: Ingo Molnar

tracing: Remove duplicate id information in event structure

2010-05-14T18:33:15+00:00

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 
Acked-by: Masami Hiramatsu 
Acked-by: Frederic Weisbecker 
Signed-off-by: Steven Rostedt

tracing: Remove per event trace registering

2010-05-14T18:19:14+00:00

This patch removes the register functions of TRACE_EVENT() to enable
and disable tracepoints. The registering of a event is now down
directly in the trace_events.c file. The tracepoint_probe_register()
is now called directly.

The prototypes are no longer type checked, but this should not be
an issue since the tracepoints are created automatically by the
macros. If a prototype is incorrect in the TRACE_EVENT() macro, then
other macros will catch it.

The trace_event_class structure now holds the probes to be called
by the callbacks. This removes needing to have each event have
a separate pointer for the probe.

To handle kprobes and syscalls, since they register probes in a
different manner, a "reg" field is added to the ftrace_event_class
structure. If the "reg" field is assigned, then it will be called for
enabling and disabling of the probe for either ftrace or perf. To let
the reg function know what is happening, a new enum (trace_reg) is
created that has the type of control that is needed.

With this new rework, the 82 kernel events and 618 syscall events
has their footprint dramatically lowered:

   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
4900252	1057412	 861512	6819176	 680d68	vmlinux.regs

The size went from 6863829 to 6819176, that's a total of 44K
in savings. With tracepoints being continuously added, this is
critical that the footprint becomes minimal.

v5: Added #ifdef CONFIG_PERF_EVENTS around a reference to perf
    specific structure in trace_events.c.

v4: Fixed trace self tests to check probe because regfunc no longer
    exists.

v3: Updated to handle void *data in beginning of probe parameters.
    Also added the tracepoint: check_trace_callback_type_##call().

v2: Changed the callback probes to pass void * and typecast the
    value within the function.

Acked-by: Mathieu Desnoyers 
Acked-by: Masami Hiramatsu 
Acked-by: Frederic Weisbecker 
Signed-off-by: Steven Rostedt