linux.git/kernel/trace/trace.c, branch v3.5-rc4

tracing: Have tracing_off() actually turn tracing off

2012-06-07T02:15:14+00:00

A recent update to have tracing_on/off() only affect the ftrace ring
buffers instead of all ring buffers had a cut and paste error.
The tracing_off() did the exact same thing as tracing_on() and
would not actually turn off tracing. Unfortunately, tracing_off()
is more important to be working than tracing_on() as this is a key
development tool, as it lets the developer turn off tracing as soon
as a problem is discovered. It is also used by panic and oops code.

This bug also breaks the 'echo func:traceoff > set_ftrace_filter'

Cc:  # 3.4
Signed-off-by: Steven Rostedt

Merge branch 'tip/perf/core-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core

2012-05-21T07:44:36+00:00

Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

2012-05-21T07:17:50+00:00

Fixes for perf/core:

 - Rename some perf_target methods to avoid double negation, from Namhyung Kim.
 - Revert change to use per task events with inheritance, from Namhyung Kim.
 - Events should start disabled till children starts running, from David Ahern.

Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Ingo Molnar

tracing: Remove kernel_lock annotations

2012-05-19T12:28:51+00:00

The BKL is gone, these annotations are useless.

Link: http://lkml.kernel.org/r/1320654202-4433-1-git-send-email-richard@nod.at

Signed-off-by: Richard Weinberger 
Signed-off-by: Steven Rostedt

tracing: Fix initial buffer_size_kb state

2012-05-19T12:28:50+00:00

Make sure that the state of buffer_size_kb is initialized correctly and
returns actual size of the ring buffer.

Link: http://lkml.kernel.org/r/1336066834-1673-1-git-send-email-vnagarnaik@google.com

Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Laurent Chavey 
Cc: Justin Teravest 
Cc: David Sharp 
Signed-off-by: Vaibhav Nagarnaik 
Signed-off-by: Steven Rostedt

Merge remote-tracking branch 'tip/perf/urgent' into perf/core

2012-05-18T16:13:33+00:00

Merge reason: We are going to queue up a dependent patch:

"perf tools: Move parse event automated tests to separated object"

That depends on:

commit e7c72d8
perf tools: Add 'G' and 'H' modifiers to event parsing

Conflicts:
	tools/perf/builtin-stat.c

Conflicted with the recent 'perf_target' patches when checking the
result of perf_evsel open routines to see if a retry is needed to cope
with older kernels where the exclude guest/host perf_event_attr bits
were not used.

Signed-off-by: Arnaldo Carvalho de Melo

tracing: change CPU ring buffer state from tracing_cpumask

2012-05-16T23:50:38+00:00

According to Documentation/trace/ftrace.txt:

tracing_cpumask:

        This is a mask that lets the user only trace
        on specified CPUS. The format is a hex string
        representing the CPUS.

The tracing_cpumask currently doesn't affect the tracing state of
per-CPU ring buffers.

This patch enables/disables CPU recording as its corresponding bit in
tracing_cpumask is set/unset.

Link: http://lkml.kernel.org/r/1336096792-25373-3-git-send-email-vnagarnaik@google.com

Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Laurent Chavey 
Cc: Justin Teravest 
Cc: David Sharp 
Signed-off-by: Vaibhav Nagarnaik 
Signed-off-by: Steven Rostedt

tracing: Check return value of tracing_dentry_percpu()

2012-05-16T23:50:37+00:00

If tracing_dentry_percpu() failed, tracing_init_debugfs_percpu()
will try to create each cpu directories on debugfs' root directory
as d_percpu is NULL.

Link: http://lkml.kernel.org/r/1335143517-2285-1-git-send-email-namhyung.kim@lge.com

Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Signed-off-by: Namhyung Kim 
Signed-off-by: Steven Rostedt

ring-buffer: Make removal of ring buffer pages atomic

2012-05-16T20:18:57+00:00

This patch adds the capability to remove pages from a ring buffer
without destroying any existing data in it.

This is done by removing the pages after the tail page. This makes sure
that first all the empty pages in the ring buffer are removed. If the
head page is one in the list of pages to be removed, then the page after
the removed ones is made the head page. This removes the oldest data
from the ring buffer and keeps the latest data around to be read.

To do this in a non-racey manner, tracing is stopped for a very short
time while the pages to be removed are identified and unlinked from the
ring buffer. The pages are freed after the tracing is restarted to
minimize the time needed to stop tracing.

The context in which the pages from the per-cpu ring buffer are removed
runs on the respective CPU. This minimizes the events not traced to only
NMI trace contexts.

Link: http://lkml.kernel.org/r/1336096792-25373-1-git-send-email-vnagarnaik@google.com

Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Laurent Chavey 
Cc: Justin Teravest 
Cc: David Sharp 
Signed-off-by: Vaibhav Nagarnaik 
Signed-off-by: Steven Rostedt

tracing: Clean up tracing_mark_write()

2012-05-16T20:18:57+00:00

On gcc 4.5 the function tracing_mark_write() would give a warning
of page2 being uninitialized. This is due to a bug in gcc because
the logic prevents page2 from being used uninitialized, and
gcc 4.6+ does not complain (correctly).

Instead of adding a "unitialized" around page2, which could show
a bug later on, I combined page1 and page2 into an array map_pages[].
This binds the two and the two are modified according to nr_pages
(what gcc 4.5 seems to ignore). This no longer gives a warning with
gcc 4.5 nor with gcc 4.6.

Signed-off-by: Steven Rostedt