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  1. 22 9月, 2009 1 次提交
  3. 19 9月, 2009 1 次提交
  5. 18 9月, 2009 1 次提交
  7. 16 9月, 2009 1 次提交
  9. 12 9月, 2009 1 次提交
  11. 19 8月, 2009 1 次提交
    • J
      tracing: handle broken names in ftrace filter · eda1e328
      由 Jiri Olsa 提交于 
      If one filter item (for set_ftrace_filter and set_ftrace_notrace) is being
setup by more than 1 consecutive writes (FTRACE_ITER_CONT flag), it won't
be handled corretly.

I used following program to test/verify:

[snip]
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>

int main(int argc, char **argv)
{
        int fd, i;
        char *file = argv[1];

        if (-1 == (fd = open(file, O_WRONLY))) {
                perror("open failed");
                return -1;
        }

        for(i = 0; i < (argc - 2); i++) {
                int len = strlen(argv[2+i]);
                int cnt, off = 0;

                while(len) {
                        cnt = write(fd, argv[2+i] + off, len);
                        len -= cnt;
                        off += cnt;
                }
        }

        close(fd);
        return 0;
}
[snip]

before change:
sh-4.0# echo > ./set_ftrace_filter
sh-4.0# /test ./set_ftrace_filter "sys" "_open "
sh-4.0# cat ./set_ftrace_filter
#### all functions enabled ####
sh-4.0#

after change:
sh-4.0# echo > ./set_ftrace_notrace
sh-4.0# test ./set_ftrace_notrace "sys" "_open "
sh-4.0# cat ./set_ftrace_notrace
sys_open
sh-4.0#
Signed-off-by: NJiri Olsa <jolsa@redhat.com>
LKML-Reference: <20090811152904.GA26065@jolsa.lab.eng.brq.redhat.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      eda1e328
  13. 17 8月, 2009 1 次提交
  15. 23 7月, 2009 2 次提交
  17. 18 7月, 2009 1 次提交
  19. 17 7月, 2009 2 次提交
  21. 13 7月, 2009 1 次提交
  23. 27 6月, 2009 1 次提交
    • L
      tracing: Fix stack tracer sysctl handling · a32c7765
      由 Li Zefan 提交于 
      This made my machine completely frozen:

  # echo 1 > /proc/sys/kernel/stack_tracer_enabled
  # echo 2 > /proc/sys/kernel/stack_tracer_enabled

The cause is register_ftrace_function() was called twice.

Also fix ftrace_enabled sysctl, though seems nothing bad happened
as I tested it.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A448D17.9010305@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      a32c7765
  25. 26 6月, 2009 1 次提交
  27. 24 6月, 2009 3 次提交
    • L
      ftrace: Fix t_hash_start() · d82d6244
      由 Li Zefan 提交于 
      When the output of set_ftrace_filter is larger than PAGE_SIZE,
t_hash_start() will be called the 2nd time, and then we start
from the head of a hlist, which is wrong and causes some entries
to be outputed twice.

The worse is, if the hlist is large enough, reading set_ftrace_filter
won't stop but in a dead loop.
Reviewed-by: NLiming Wang <liming.wang@windriver.com>
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A41876E.2060407@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      d82d6244
    • L
      ftrace: Don't manipulate @pos in t_start() · 694ce0a5
      由 Li Zefan 提交于 
      It's rather confusing that in t_start(), in some cases @pos is
incremented, and in some cases it's decremented and then incremented.

This patch rewrites t_start() in a much more general way.

Thus we fix a bug that if ftrace_filtered == 1, functions have tracer
hooks won't be printed, because the branch is always unreachable:

static void *t_start(...)
{
	...
	if (!p)
		return t_hash_start(m, pos);
	return p;
}

Before:
  # echo 'sys_open' > /mnt/tracing/set_ftrace_filter
  # echo 'sys_write:traceon:4' >> /mnt/tracing/set_ftrace_filter
  sys_open

After:
  # echo 'sys_open' > /mnt/tracing/set_ftrace_filter
  # echo 'sys_write:traceon:4' >> /mnt/tracing/set_ftrace_filter
  sys_open
  sys_write:traceon:count=4
Reviewed-by: NLiming Wang <liming.wang@windriver.com>
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A41874B.4090507@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      694ce0a5
    • L
      ftrace: Don't increment @pos in g_start() · 85951842
      由 Li Zefan 提交于 
      It's wrong to increment @pos in g_start(). It causes some entries
lost when reading set_graph_function, if the output of the file
is larger than PAGE_SIZE.
Reviewed-by: NLiming Wang <liming.wang@windriver.com>
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A418738.7090401@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      85951842
  29. 20 6月, 2009 1 次提交
  31. 03 6月, 2009 4 次提交
    • S
      function-graph: always initialize task ret_stack · 84047e36
      由 Steven Rostedt 提交于 
      On creating a new task while running the function graph tracer, if
we fail to allocate the ret_stack, and then fail the fork, the
code will free the parent ret_stack. This is because the child
duplicated the parent and currently points to the parent's ret_stack.

This patch always initializes the task's ret_stack to NULL.

[ Impact: prevent crash of parent on low memory during fork ]
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      84047e36
    • S
      function-graph: add memory barriers for accessing task's ret_stack · 26c01624
      由 Steven Rostedt 提交于 
      The code that handles the tasks ret_stack allocation for every task
assumes that only an interrupt can cause issues (even though interrupts
are disabled).

In reality, the code is allocating the ret_stack for tasks that may be
running on other CPUs and there are not efficient memory barriers to
handle this case.

[ Impact: prevent crash due to using of uninitialized ret_stack variables ]
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      26c01624
    • S
      function-graph: enable the stack after initialization of other variables · 82310a32
      由 Steven Rostedt 提交于 
      The function graph tracer checks if the task_struct has ret_stack defined
to know if it is OK or not to use it. The initialization is done for
all tasks by one process, but the idle tasks use the same initialization
used by new tasks.

If an interrupt happens on an idle task that just had the ret_stack
created, but before the rest of the initialization took place, then
we can corrupt the return address of the functions.

This patch moves the setting of the task_struct's ret_stack to after
the other variables have been initialized.

[ Impact: prevent kernel panic on idle task when starting function graph ]
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      82310a32
    • S
      function-graph: only allocate init tasks if it was not already done · 179c498a
      由 Steven Rostedt 提交于 
      When the function graph tracer is enabled, it calls the initialization
needed for the init tasks that would be called on all created tasks.

The problem is that this is called every time the function graph tracer
is enabled, and the ret_stack is allocated for the idle tasks each time.
Thus, the old ret_stack is lost and a memory leak is created.

This is also dangerous because if an interrupt happened on another CPU
with the init task and the ret_stack is replaced, we then lose all the
return pointers for the interrupt, and a crash would take place.

[ Impact: fix memory leak and possible crash due to race ]
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      179c498a
  33. 02 6月, 2009 2 次提交
    • S
      ftrace: do not profile functions when disabled · 0f6ce3de
      由 Steven Rostedt 提交于 
      A race was found that if one were to enable and disable the function
profiler repeatedly, then the system can panic. This was because a profiled
function may be preempted just before disabling interrupts. While
the profiler is disabled and then reenabled, the preempted function
could start again, and access the hash as it is being initialized.

This just adds a check in the irq disabled part to check if the profiler
is enabled, and if it is not then it will just exit.

When the system is disabled, the profile_enabled variable is cleared
before calling the unregistering of the function profiler. This
unregistering calls stop machine which also acts as a synchronize schedule.

[ Impact: fix panic in enabling/disabling function profiler ]
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      0f6ce3de
    • S
      ftrace: add kernel command line function filtering · 2af15d6a
      由 Steven Rostedt 提交于 
      When using ftrace=function on the command line to trace functions
on boot up, one can not filter out functions that are commonly called.

This patch adds two new ftrace command line commands.

  ftrace_notrace=function-list
  ftrace_filter=function-list

Where function-list is a comma separated list of functions to filter.
The ftrace_notrace will make the functions listed not be included
in the function tracing, and ftrace_filter will only trace the functions
listed.

These two act the same as the debugfs/tracing/set_ftrace_notrace and
debugfs/tracing/set_ftrace_filter respectively.

The simple glob expressions that are allowed by the filter files can also
be used by the command line interface.

	ftrace_notrace=rcu*,*lock,*spin*

Will not trace any function that starts with rcu, ends with lock, or has
the word spin in it.

Note, if the self tests are enabled, they may interfere with the filtering
set by the command lines.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      2af15d6a
  35. 18 5月, 2009 1 次提交
  37. 17 4月, 2009 1 次提交
    • S
      ftrace: use module notifier for function tracer · 93eb677d
      由 Steven Rostedt 提交于 
      The hooks in the module code for the function tracer must be called
before any of that module code runs. The function tracer hooks
modify the module (replacing calls to mcount to nops). If the code
is executed while the change occurs, then the CPU can take a GPF.

To handle the above with a bit of paranoia, I originally implemented
the hooks as calls directly from the module code.

After examining the notifier calls, it looks as though the start up
notify is called before any of the module's code is executed. This makes
the use of the notify safe with ftrace.

Only the startup notify is required to be "safe". The shutdown simply
removes the entries from the ftrace function list, and does not modify
any code.

This change has another benefit. It removes a issue with a reverse dependency
in the mutexes of ftrace_lock and module_mutex.

[ Impact: fix lock dependency bug, cleanup ]

Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      93eb677d
  39. 15 4月, 2009 1 次提交
    • S
      tracing/events: move trace point headers into include/trace/events · ad8d75ff
      由 Steven Rostedt 提交于 
      Impact: clean up

Create a sub directory in include/trace called events to keep the
trace point headers in their own separate directory. Only headers that
declare trace points should be defined in this directory.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      ad8d75ff
  41. 07 4月, 2009 2 次提交
  43. 01 4月, 2009 1 次提交
    • S
      function-graph: allow unregistering twice · 2aad1b76
      由 Steven Rostedt 提交于 
      Impact: fix to permanent disabling of function graph tracer

There should be nothing to prevent a tracer from unregistering a
function graph callback more than once. This can simplify error paths.

But currently, the counter does not account for mulitple unregistering
of the function graph callback. If it happens, the function graph
tracer will be permanently disabled.
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      2aad1b76
  45. 30 3月, 2009 1 次提交
  47. 26 3月, 2009 4 次提交
  49. 25 3月, 2009 4 次提交
    • S
      function-graph: add option to calculate graph time or not · a2a16d6a
      由 Steven Rostedt 提交于 
      graph time is the time that a function is executing another function.
Thus if function A calls B, if graph-time is set, then the time for
A includes B. This is the default behavior. But if graph-time is off,
then the time spent executing B is subtracted from A.
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
      a2a16d6a
    • S
      tracing: make the function profiler per cpu · cafb168a
      由 Steven Rostedt 提交于 
      Impact: speed enhancement

By making the function profiler record in per cpu data we not only
get better readings, avoid races, we also do not have to take any
locks.
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
      cafb168a
    • S
      tracing: adding function timings to function profiler · 0706f1c4
      由 Steven Rostedt 提交于 
      If the function graph trace is enabled, the function profiler will
use it to take the timing of the functions.

 cat /debug/tracing/trace_stat/functions

  Function                               Hit    Time
  --------                               ---    ----
  mwait_idle                             127    183028.4 us
  schedule                                26    151997.7 us
  __schedule                              31    151975.1 us
  sys_wait4                                2    74080.53 us
  do_wait                                  2    74077.80 us
  sys_newlstat                           138    39929.16 us
  do_path_lookup                         179    39845.79 us
  vfs_lstat_fd                           138    39761.97 us
  user_path_at                           153    39469.58 us
  path_walk                              179    39435.76 us
  __link_path_walk                       189    39143.73 us
[...]

Note the times are skewed due to the function graph tracer not taking
into account schedules.
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
      0706f1c4
    • S
      tracing: move function profiler data out of function struct · 493762fc
      由 Steven Rostedt 提交于 
      Impact: reduce size of memory in function profiler

The function profiler originally introduces its counters into the
function records itself. There is 20 thousand different functions on
a normal system, and that is adding 20 thousand counters for profiling
event when not needed.

A normal run of the profiler yields only a couple of thousand functions
executed, depending on what is being profiled. This means we have around
18 thousand useless counters.

This patch rectifies this by moving the data out of the function
records used by dynamic ftrace. Data is preallocated to hold the functions
when the profiling begins. Checks are made during profiling to see if
more recorcds should be allocated, and they are allocated if it is safe
to do so.

This also removes the dependency from using dynamic ftrace, and also
removes the overhead by having it enabled.
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
      493762fc