linux-toradex.git/drivers/oprofile, branch v2.6.32.21

oprofile: remove double ring buffering

2010-07-05T18:10:27+00:00

commit cb6e943ccf19ab6d3189147e9d625a992e016084 upstream.

oprofile used a double buffer scheme for its cpu event buffer
to avoid races on reading with the old locked ring buffer.

But that is obsolete now with the new ring buffer, so simply
use a single buffer. This greatly simplifies the code and avoids
a lot of sample drops on large runs, especially with call graph.

Based on suggestions from Steven Rostedt

For stable kernels from v2.6.32, but not earlier.

Signed-off-by: Andi Kleen 
Cc: Steven Rostedt 
Signed-off-by: Robert Richter 
Signed-off-by: Greg Kroah-Hartman

oprofile: warn on freeing event buffer too early

2009-10-09T19:32:05+00:00

A race shouldn't happen since all workqueues or handlers are canceled
or flushed before the event buffer is freed. A warning is triggered
now if the buffer is freed too early.

Also, this patch adds some comments about event buffer protection,
reworks some code and adds code to clear buffer_pos during alloc and
free of the event buffer.

Cc: David Rientjes 
Cc: Stephane Eranian 
Signed-off-by: Robert Richter

oprofile: fix race condition in event_buffer free

2009-10-09T16:02:01+00:00

Looking at the 2.6.31-rc9 code, it appears there is a race condition
in the event_buffer cleanup code path (shutdown). This could lead to
kernel panic as some CPUs may be operating on the event buffer AFTER
it has been freed. The attached patch solves the problem and makes
sure CPUs check if the buffer is not NULL before they access it as
some may have been spinning on the mutex while the buffer was being
freed.

The race may happen if the buffer is freed during pending reads. But
it is not clear why there are races in add_event_entry() since all
workqueues or handlers are canceled or flushed before the event buffer
is freed.

Signed-off-by: David Rientjes 
Signed-off-by: Stephane Eranian 
Signed-off-by: Robert Richter

cpumask: use zalloc_cpumask_var() where possible

2009-09-24T00:04:24+00:00

Remove open-coded zalloc_cpumask_var() and zalloc_cpumask_var_node().

Signed-off-by: Li Zefan 
Signed-off-by: Rusty Russell

const: mark remaining super_operations const

2009-09-22T14:17:24+00:00

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

oprofile: Adding switch counter to oprofile statistic variables

2009-07-20T14:43:21+00:00

This patch moves the multiplexing switch counter from x86 code to
common oprofile statistic variables. Now the value will be available
and usable for all architectures. The initialization and
incrementation also moved to common code.

Signed-off-by: Robert Richter

oprofile: Grouping multiplexing code in oprof.c

2009-07-20T14:43:19+00:00

This patch moves multiplexing code to a single section of code. This
reduces the use of #ifdefs especially within functions.

Signed-off-by: Robert Richter

oprofile: Remove oprofile_multiplexing_init()

2009-07-20T14:43:19+00:00

oprofile_multiplexing_init() can be removed when moving the
initialization of oprofile_time_slice to oprofile_create_files().

Signed-off-by: Robert Richter

oprofile: Rename variable timeout_jiffies and move to oprofile_files.c

2009-07-20T14:43:19+00:00

This patch renames timeout_jiffies into an oprofile specific name. The
macro MULTIPLEXING_TIMER_DEFAULT is changed too.

Also, since this variable is controlled using oprofilefs, its
definition is moved to oprofile_files.c.

Signed-off-by: Robert Richter

oprofile: oprofile_set_timeout(), return with error for invalid args

2009-07-20T14:43:18+00:00

Return with -EINVAL for invalid parameters instead of setting the
default value in oprofile_set_timeout().

Signed-off-by: Robert Richter