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  1. 09 8月, 2011 1 次提交
  3. 08 8月, 2011 5 次提交
  5. 03 8月, 2011 1 次提交
  7. 26 7月, 2011 1 次提交
  9. 25 7月, 2011 1 次提交
  11. 22 7月, 2011 5 次提交
  13. 21 7月, 2011 8 次提交
  15. 16 7月, 2011 11 次提交
  17. 15 7月, 2011 5 次提交
    • S
      ftrace: Fix regression where ftrace breaks when modules are loaded · f7bc8b61
      由 Steven Rostedt 提交于 
      Enabling function tracer to trace all functions, then load a module and
then disable function tracing will cause ftrace to fail.

This can also happen by enabling function tracing on the command line:

  ftrace=function

and during boot up, modules are loaded, then you disable function tracing
with 'echo nop > current_tracer' you will trigger a bug in ftrace that
will shut itself down.

The reason is, the new ftrace code keeps ref counts of all ftrace_ops that
are registered for tracing. When one or more ftrace_ops are registered,
all the records that represent the functions that the ftrace_ops will
trace have a ref count incremented. If this ref count is not zero,
when the code modification runs, that function will be enabled for tracing.
If the ref count is zero, that function will be disabled from tracing.

To make sure the accounting was working, FTRACE_WARN_ON()s were added
to updating of the ref counts.

If the ref count hits its max (> 2^30 ftrace_ops added), or if
the ref count goes below zero, a FTRACE_WARN_ON() is triggered which
disables all modification of code.

Since it is common for ftrace_ops to trace all functions in the kernel,
instead of creating > 20,000 hash items for the ftrace_ops, the hash
count is just set to zero, and it represents that the ftrace_ops is
to trace all functions. This is where the issues arrise.

If you enable function tracing to trace all functions, and then add
a module, the modules function records do not get the ref count updated.
When the function tracer is disabled, all function records ref counts
are subtracted. Since the modules never had their ref counts incremented,
they go below zero and the FTRACE_WARN_ON() is triggered.

The solution to this is rather simple. When modules are loaded, and
their functions are added to the the ftrace pool, look to see if any
ftrace_ops are registered that trace all functions. And for those,
update the ref count for the module function records.
Reported-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      f7bc8b61
    • M
      tracing/kprobes: Rename probe_* to trace_probe_* · 7143f168
      由 Masami Hiramatsu 提交于 
      Rename probe_* to trace_probe_* for avoiding namespace
confliction. This also fixes improper names of find_probe_event()
and cleanup_all_probes() to find_trace_probe() and
release_all_trace_probes() respectively.
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20110627072636.6528.60374.stgit@fedora15Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      7143f168
    • C
      perf, x86: P4 PMU - Introduce event alias feature · f9129870
      由 Cyrill Gorcunov 提交于 
      Instead of hw_nmi_watchdog_set_attr() weak function
and appropriate x86_pmu::hw_watchdog_set_attr() call
we introduce even alias mechanism which allow us
to drop this routines completely and isolate quirks
of Netburst architecture inside P4 PMU code only.

The main idea remains the same though -- to allow
nmi-watchdog and perf top run simultaneously.

Note the aliasing mechanism applies to generic
PERF_COUNT_HW_CPU_CYCLES event only because arbitrary
event (say passed as RAW initially) might have some
additional bits set inside ESCR register changing
the behaviour of event and we can't guarantee anymore
that alias event will give the same result.

P.S. Thanks a huge to Don and Steven for for testing
     and early review.
Acked-by: NDon Zickus <dzickus@redhat.com>
Tested-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
CC: Ingo Molnar <mingo@elte.hu>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Stephane Eranian <eranian@google.com>
CC: Lin Ming <ming.m.lin@intel.com>
CC: Arnaldo Carvalho de Melo <acme@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20110708201712.GS23657@sunSigned-off-by: NSteven Rostedt <rostedt@goodmis.org>
      f9129870
    • S
      tracing: Have dynamic size event stack traces · 4a9bd3f1
      由 Steven Rostedt 提交于 
      Currently the stack trace per event in ftace is only 8 frames.
This can be quite limiting and sometimes useless. Especially when
the "ignore frames" is wrong and we also use up stack frames for
the event processing itself.

Change this to be dynamic by adding a percpu buffer that we can
write a large stack frame into and then copy into the ring buffer.

For interrupts and NMIs that come in while another event is being
process, will only get to use the 8 frame stack. That should be enough
as the task that it interrupted will have the full stack frame anyway.
Requested-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      4a9bd3f1
    • S
      perf: Robustify proc and debugfs file recording · 259032bf
      由 Sonny Rao 提交于 
      While attempting to create a timechart of boot up I found perf didn't
tolerate modules being loaded/unloaded.  This patch fixes this by
reading the file once and then writing the size read at the correct
point in the file.  It also simplifies the code somewhat.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: NSonny Rao <sonnyrao@chromium.org>
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Link: http://lkml.kernel.org/r/10011.1310614483@neuling.orgSigned-off-by: NSteven Rostedt <rostedt@goodmis.org>
      259032bf
  19. 14 7月, 2011 2 次提交
    • S
      ftrace: Fix dynamic selftest failure on some archs · 6331c28c
      由 Steven Rostedt 提交于 
      Archs that do not implement CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST, will
fail the dynamic ftrace selftest.

The function tracer has a quick 'off' variable that will prevent
the call back functions from being called. This variable is called
function_trace_stop. In x86, this is implemented directly in the mcount
assembly, but for other archs, an intermediate function is used called
ftrace_test_stop_func().

In dynamic ftrace, the function pointer variable ftrace_trace_function is
used to update the caller code in the mcount caller. But for archs that
do not have CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST set, it only calls
ftrace_test_stop_func() instead, which in turn calls __ftrace_trace_function.

When more than one ftrace_ops is registered, the function it calls is
ftrace_ops_list_func(), which will iterate over all registered ftrace_ops
and call the callbacks that have their hash matching.

The issue happens when two ftrace_ops are registered for different functions
and one is then unregistered. The __ftrace_trace_function is then pointed
to the remaining ftrace_ops callback function directly. This mean it will
be called for all functions that were registered to trace by both ftrace_ops
that were registered.

This is not an issue for archs with CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST,
because the update of ftrace_trace_function doesn't happen until after all
functions have been updated, and then the mcount caller is updated. But
for those archs that do use the ftrace_test_stop_func(), the update is
immediate.

The dynamic selftest fails because it hits this situation, and the
ftrace_ops that it registers fails to only trace what it was suppose to
and instead traces all other functions.

The solution is to delay the setting of __ftrace_trace_function until
after all the functions have been updated according to the registered
ftrace_ops. Also, function_trace_stop is set during the update to prevent
function tracing from calling code that is caused by the function tracer
itself.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      6331c28c
    • S
      ftrace: Update filter when tracing enabled in set_ftrace_filter() · 072126f4
      由 Steven Rostedt 提交于 
      Currently, if set_ftrace_filter() is called when the ftrace_ops is
active, the function filters will not be updated. They will only be updated
when tracing is disabled and re-enabled.

Update the functions immediately during set_ftrace_filter().
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      072126f4