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  1. 20 4月, 2016 13 次提交
  3. 19 4月, 2016 1 次提交
    • S
      tracing: Add infrastructure to allow set_event_pid to follow children · c37775d5
      由 Steven Rostedt 提交于 
      Add the infrastructure needed to have the PIDs in set_event_pid to
automatically add PIDs of the children of the tasks that have their PIDs in
set_event_pid. This will also remove PIDs from set_event_pid when a task
exits

This is implemented by adding hooks into the fork and exit tracepoints. On
fork, the PIDs are added to the list, and on exit, they are removed.

Add a new option called event_fork that when set, PIDs in set_event_pid will
automatically get their children PIDs added when they fork, as well as any
task that exits will have its PID removed from set_event_pid.

This works for instances as well.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      c37775d5
  5. 23 3月, 2016 2 次提交
  7. 19 3月, 2016 1 次提交
  9. 18 3月, 2016 1 次提交
  11. 09 3月, 2016 1 次提交
    • C
      tracing: Make tracer_flags use the right set_flag callback · d39cdd20
      由 Chunyu Hu 提交于 
      When I was updating the ftrace_stress test of ltp. I encountered
a strange phenomemon, excute following steps:

echo nop > /sys/kernel/debug/tracing/current_tracer
echo 0 > /sys/kernel/debug/tracing/options/funcgraph-cpu
bash: echo: write error: Invalid argument

check dmesg:
[ 1024.903855] nop_test_refuse flag set to 0: we refuse.Now cat trace_options to see the result

The reason is that the trace option test will randomly setup trace
option under tracing/options no matter what the current_tracer is.
but the set_tracer_option is always using the set_flag callback
from the current_tracer. This patch adds a pointer to tracer_flags
and make it point to the tracer it belongs to. When the option is
setup, the set_flag of the right tracer will be used no matter
what the the current_tracer is.

And the old dummy_tracer_flags is used for all the tracers which
doesn't have a tracer_flags, having issue to use it to save the
pointer of a tracer. So remove it and use dynamic dummy tracer_flags
for tracers needing a dummy tracer_flags, as a result, there are no
tracers sharing tracer_flags, so remove the check code.

And save the current tracer to trace_option_dentry seems not good as
it may waste mem space when mount the debug/trace fs more than one time.

Link: http://lkml.kernel.org/r/1457444222-8654-1-git-send-email-chuhu@redhat.comSigned-off-by: NChunyu Hu <chuhu@redhat.com>
[ Fixed up function tracer options to work with the change ]
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      d39cdd20
  13. 14 1月, 2016 1 次提交
    • S
      tracing: Fix stacktrace skip depth in trace_buffer_unlock_commit_regs() · 7717c6be
      由 Steven Rostedt (Red Hat) 提交于 
      While cleaning the stacktrace code I unintentially changed the skip depth of
trace_buffer_unlock_commit_regs() from 0 to 6. kprobes uses this function,
and with skipping 6 call backs, it can easily produce no stack.

Here's how I tested it:

 # echo 'p:ext4_sync_fs ext4_sync_fs ' > /sys/kernel/debug/tracing/kprobe_events
 # echo 1 > /sys/kernel/debug/tracing/events/kprobes/enable
 # cat /sys/kernel/debug/trace
            sync-2394  [005]   502.457060: ext4_sync_fs: (ffffffff81317650)
            sync-2394  [005]   502.457063: kernel_stack:         <stack trace>
            sync-2394  [005]   502.457086: ext4_sync_fs: (ffffffff81317650)
            sync-2394  [005]   502.457087: kernel_stack:         <stack trace>
            sync-2394  [005]   502.457091: ext4_sync_fs: (ffffffff81317650)

After putting back the skip stack to zero, we have:

            sync-2270  [000]   748.052693: ext4_sync_fs: (ffffffff81317650)
            sync-2270  [000]   748.052695: kernel_stack:         <stack trace>
 => iterate_supers (ffffffff8126412e)
 => sys_sync (ffffffff8129c4b6)
 => entry_SYSCALL_64_fastpath (ffffffff8181f0b2)
            sync-2270  [000]   748.053017: ext4_sync_fs: (ffffffff81317650)
            sync-2270  [000]   748.053019: kernel_stack:         <stack trace>
 => iterate_supers (ffffffff8126412e)
 => sys_sync (ffffffff8129c4b6)
 => entry_SYSCALL_64_fastpath (ffffffff8181f0b2)
            sync-2270  [000]   748.053381: ext4_sync_fs: (ffffffff81317650)
            sync-2270  [000]   748.053383: kernel_stack:         <stack trace>
 => iterate_supers (ffffffff8126412e)
 => sys_sync (ffffffff8129c4b6)
 => entry_SYSCALL_64_fastpath (ffffffff8181f0b2)

Cc: stable@vger.kernel.org # v4.4+
Fixes: 73dddbb5 "tracing: Only create stacktrace option when STACKTRACE is configured"
Reported-by: NBrendan Gregg <brendan.d.gregg@gmail.com>
Tested-by: NBrendan Gregg <brendan.d.gregg@gmail.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      7717c6be
  15. 10 11月, 2015 1 次提交
  17. 08 11月, 2015 1 次提交
  19. 06 11月, 2015 1 次提交
  21. 04 11月, 2015 3 次提交
  23. 03 11月, 2015 1 次提交
  25. 01 10月, 2015 6 次提交
  27. 30 9月, 2015 7 次提交
    • S
      tracing: Remove access to trace_flags in trace_printk.c · b9f9108c
      由 Steven Rostedt (Red Hat) 提交于 
      In the effort to move the global trace_flags to the tracing instances, the
direct access to trace_flags must be removed from trace_printk.c

Instead, add a new trace_printk_enabled boolean that is set by a new access
function trace_printk_control(), that will enable or disable trace_printk.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      b9f9108c
    • S
      tracing: Add build bug if we have more trace_flags than bits · b5e87c05
      由 Steven Rostedt (Red Hat) 提交于 
      Add a enum that denotes the last bit of the trace_flags and have a
BUILD_BUG_ON(last_bit > 32).

If we add more bits than we have in trace_flags, the kernel wont build.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      b5e87c05
    • S
      tracing: Always show all tracer options in the options directory · 41d9c0be
      由 Steven Rostedt (Red Hat) 提交于 
      There are options that are unique to a specific tracer (like function and
function graph). Currently, these options are only visible in the options
directory when the tracer is enabled.

This has been a pain, especially for something like the func_stack_trace
option that if used inappropriately, could bring the system to a crawl. But
the only way to see it, is to enable the function tracer.

For example, if one had done:

 # cd /sys/kernel/tracing
 # echo __schedule > set_ftrace_filter
 # echo 1 > options/func_stack_trace
 # echo function > current_tracer

The __schedule call will be traced and a stack trace will also be recorded
there. Now when you were done, you may do...

 # echo nop > current_tracer
 # echo > set_ftrace_filter

But you forgot to disable the func_stack_trace. The only way to disable it
is to re-enable function tracing first. If you do not add a filter to
set_ftrace_filter and just do:

 # echo function > current_tracer

Now you would be performing a stack trace on *every* function! On some
systems, that causes a live lock. Others may take a few minutes to fix your
mistake.

Having the func_stack_trace option visible allows you to check it and
disable it before enabling the funtion tracer.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      41d9c0be
    • S
      tracing: Only create stacktrace option when STACKTRACE is configured · 73dddbb5
      由 Steven Rostedt (Red Hat) 提交于 
      Only create the stacktrace trace option when CONFIG_STACKTRACE is
configured.

Cleaned up the ftrace_trace_stack() function call a little to allow better
encapsulation of the stacktrace trace flag.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      73dddbb5
    • S
      tracing: Do not create function tracer options when not compiled in · 8179e8a1
      由 Steven Rostedt (Red Hat) 提交于 
      When the function tracer is not compiled in, do not create the option files
for it.

Fix up both the sched_wakeup and irqsoff tracers to handle the change.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      8179e8a1
    • S
      tracing: Only create function graph options when it is compiled in · 729358da
      由 Steven Rostedt (Red Hat) 提交于 
      Do not create fuction graph tracer options when function graph tracer is not
even compiled in.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      729358da
    • S
      tracing: Use TRACE_FLAGS macro to keep enums and strings matched · a3418a36
      由 Steven Rostedt (Red Hat) 提交于 
      Use a cute little macro trick to keep the names of the trace flags file
guaranteed to match the corresponding masks.

The macro TRACE_FLAGS is defined as a serious of enum names followed by
the string name of the file that matches it. For example:

 #define TRACE_FLAGS						\
		C(PRINT_PARENT,		"print-parent"),	\
		C(SYM_OFFSET,		"sym-offset"),		\
		C(SYM_ADDR,		"sym-addr"),		\
		C(VERBOSE,		"verbose"),

Now we can define the following:

 #undef C
 #define C(a, b) TRACE_ITER_##a##_BIT
 enum trace_iterator_bits { TRACE_FLAGS };

The above creates:

 enum trace_iterator_bits {
	TRACE_ITER_PRINT_PARENT_BIT,
	TRACE_ITER_SYM_OFFSET_BIT,
	TRACE_ITER_SYM_ADDR_BIT,
	TRACE_ITER_VERBOSE_BIT,
 };

Then we can redefine C as:

 #undef C
 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
 enum trace_iterator_flags { TRACE_FLAGS };

Which creates:

 enum trace_iterator_flags {
	TRACE_ITER_PRINT_PARENT	= (1 << TRACE_ITER_PRINT_PARENT_BIT),
	TRACE_ITER_SYM_OFFSET	= (1 << TRACE_ITER_SYM_OFFSET_BIT),
	TRACE_ITER_SYM_ADDR	= (1 << TRACE_ITER_SYM_ADDR_BIT),
	TRACE_ITER_VERBOSE	= (1 << TRACE_ITER_VERBOSE_BIT),
 };

Then finally we can create the list of file names:

 #undef C
 #define C(a, b) b
 static const char *trace_options[] = {
	TRACE_FLAGS
	NULL
 };

Which creates:
 static const char *trace_options[] = {
	"print-parent",
	"sym-offset",
	"sym-addr",
	"verbose",
	NULL
 };

The importance of this is that the strings match the bit index.

	trace_options[TRACE_ITER_SYM_ADDR_BIT] == "sym-addr"
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      a3418a36