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  1. 06 8月, 2009 2 次提交
    • S
      ring-buffer: do not disable ring buffer on oops_in_progress · 464e85eb
      由 Steven Rostedt 提交于 
      The commit:

  commit e0fdace1
  Author: David Miller <davem@davemloft.net>
  Date:   Fri Aug 1 01:11:22 2008 -0700

    debug_locks: set oops_in_progress if we will log messages.

    Otherwise lock debugging messages on runqueue locks can deadlock the
    system due to the wakeups performed by printk().
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Will permanently set oops_in_progress on any lockdep failure.
When this triggers it will cause any read from the ring buffer to
permanently disable the ring buffer (not to mention no locking of
printk).

This patch removes the check. It keeps the print in NMI which makes
sense. This is probably OK, since the ring buffer should not cause
something to set oops_in_progress anyway.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      464e85eb
    • S
      ring-buffer: fix check of try_to_discard result · 0f2541d2
      由 Steven Rostedt 提交于 
      The function ring_buffer_discard_commit inversed the code path
of the result of try_to_discard. It should skip incrementing the
entry counter if try_to_discard succeeded. But instead, it increments
the entry conder if it succeeded to discard, and does not increment
it if it fails.

The result of this bug is that filtering will make the stat counters
incorrect.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      0f2541d2
  3. 04 8月, 2009 1 次提交
  5. 29 7月, 2009 2 次提交
    • L
      tracing: Fix missing function_graph events when we splice_read from trace_pipe · 74e7ff8c
      由 Lai Jiangshan 提交于 
      About a half events are missing when we splice_read
from trace_pipe. They are unexpectedly consumed because we ignore
the TRACE_TYPE_NO_CONSUME return value used by the function graph
tracer when it needs to consume the events by itself to walk on
the ring buffer.

The same problem appears with ftrace_dump()

Example of an output before this patch:

1)               |      ktime_get_real() {
1)   2.846 us    |          read_hpet();
1)   4.558 us    |        }
1)   6.195 us    |      }

After this patch:

0)               |      ktime_get_real() {
0)               |        getnstimeofday() {
0)   1.960 us    |          read_hpet();
0)   3.597 us    |        }
0)   5.196 us    |      }

The fix also applies on 2.6.30
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: stable@kernel.org
LKML-Reference: <4A6EEC52.90704@cn.fujitsu.com>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      74e7ff8c
    • L
      tracing: Fix invalid function_graph entry · 38ceb592
      由 Lai Jiangshan 提交于 
      When print_graph_entry() computes a function call entry event, it needs
to also check the next entry to guess if it matches the return event of
the current function entry.
In order to look at this next event, it needs to consume the current
entry before going ahead in the ring buffer.

However, if the current event that gets consumed is the last one in the
ring buffer head page, the ring_buffer may reuse the page for writers.
The consumed entry will then become invalid because of possible
racy overwriting.

Me must then handle this entry by making a copy of it.

The fix also applies on 2.6.30
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: stable@kernel.org
LKML-Reference: <4A6EEAEC.3050508@cn.fujitsu.com>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      38ceb592
  7. 28 7月, 2009 21 次提交
  9. 27 7月, 2009 14 次提交