linux/kernel/trace
Peter Zijlstra 1f8a6a10fb ring-buffer: pass in lockdep class key for reader_lock
On Sun, 7 Jun 2009, Ingo Molnar wrote:
> Testing tracer sched_switch: <6>Starting ring buffer hammer
> PASSED
> Testing tracer sysprof: PASSED
> Testing tracer function: PASSED
> Testing tracer irqsoff:
> =============================================
> PASSED
> Testing tracer preemptoff: PASSED
> Testing tracer preemptirqsoff: [ INFO: possible recursive locking detected ]
> PASSED
> Testing tracer branch: 2.6.30-rc8-tip-01972-ge5b9078-dirty #5760
> ---------------------------------------------
> rb_consumer/431 is trying to acquire lock:
>  (&cpu_buffer->reader_lock){......}, at: [<c109eef7>] ring_buffer_reset_cpu+0x37/0x70
>
> but task is already holding lock:
>  (&cpu_buffer->reader_lock){......}, at: [<c10a019e>] ring_buffer_consume+0x7e/0xc0
>
> other info that might help us debug this:
> 1 lock held by rb_consumer/431:
>  #0:  (&cpu_buffer->reader_lock){......}, at: [<c10a019e>] ring_buffer_consume+0x7e/0xc0

The ring buffer is a generic structure, and can be used outside of
ftrace. If ftrace traces within the use of the ring buffer, it can produce
false positives with lockdep.

This patch passes in a static lock key into the allocation of the ring
buffer, so that different ring buffers will have their own lock class.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1244477919.13761.9042.camel@twins>

[ store key in ring buffer descriptor ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-08 18:50:20 -04:00
..
blktrace.c blktrace: remove debugfs entries on bad path 2009-05-19 10:29:21 +02:00
ftrace.c ftrace: do not profile functions when disabled 2009-06-01 23:26:23 -04:00
Kconfig tracing: combine the default tracers into one config 2009-06-01 23:23:55 -04:00
kmemtrace.c tracing/filters: use ring_buffer_discard_commit() in filter_check_discard() 2009-04-14 00:00:56 +02:00
Makefile Merge branch 'tracing/hw-branch-tracing' into tracing/core 2009-05-07 13:36:22 +02:00
ring_buffer_benchmark.c ring-buffer: check for divide by zero in ring-buffer-benchmark 2009-05-11 13:22:26 -04:00
ring_buffer.c ring-buffer: pass in lockdep class key for reader_lock 2009-06-08 18:50:20 -04:00
trace_boot.c tracing: use macros to denote usec and nsec per second 2009-04-07 14:43:06 +02:00
trace_branch.c Merge branch 'linus' into tracing/core 2009-05-07 11:17:34 +02:00
trace_clock.c tracing: fix four sparse warnings 2009-03-22 18:16:54 +01:00
trace_event_profile.c tracing/events: fix concurrent access to ftrace_events list 2009-05-06 10:38:19 +02:00
trace_event_types.h tracing/filters: distinguish between signed and unsigned fields 2009-04-29 14:06:03 +02:00
trace_events_filter.c tracing/events: introduce __dynamic_array() 2009-06-01 23:25:15 -04:00
trace_events.c ftrace: clean up of using ftrace_event_enable_disable() 2009-05-26 03:30:31 +02:00
trace_export.c tracing/filters: distinguish between signed and unsigned fields 2009-04-29 14:06:03 +02:00
trace_functions_graph.c function-graph: add option to calculate graph time or not 2009-03-24 23:41:11 -04:00
trace_functions.c tracing/core: use appropriate waiting on trace_pipe 2009-02-18 01:40:20 +01:00
trace_hw_branches.c Merge branch 'tracing/hw-branch-tracing' into tracing/core 2009-05-07 13:36:22 +02:00
trace_irqsoff.c tracing: have latency tracers set the latency format 2009-03-04 22:15:30 -05:00
trace_mmiotrace.c tracing: use macros to denote usec and nsec per second 2009-04-07 14:43:06 +02:00
trace_nop.c tracing/ftrace: make nop-tracer use polling wait for events on pipe 2009-03-23 09:22:15 +01:00
trace_output.c tracing: add annotation to what type of stack trace is recorded 2009-06-03 11:10:44 -04:00
trace_output.h tracing: add trace_event_read_lock() 2009-05-25 23:53:41 +02:00
trace_power.c Merge branch 'linus' into tracing/core 2009-05-07 11:17:34 +02:00
trace_printk.c tracing/ftrace: factorize the tracing files creation 2009-04-07 14:43:07 +02:00
trace_sched_switch.c tracing/events: move trace point headers into include/trace/events 2009-04-14 22:05:43 -04:00
trace_sched_wakeup.c tracing/wakeup: move access to wakeup_cpu into spinlock 2009-04-23 23:01:36 -04:00
trace_selftest_dynamic.c ftrace: fix dynamic ftrace selftest 2008-05-23 21:13:23 +02:00
trace_selftest.c x86, hw-branch-tracer: allocate selftest iterator on heap 2009-04-07 13:36:21 +02:00
trace_stack.c tracing/trace_stack: fix the number of entries in the header 2009-06-03 10:24:44 -04:00
trace_stat.c tracing/stat: remove unappropriate safe walk on list 2009-06-02 01:18:33 +02:00
trace_stat.h tracing: add handler to trace_stat 2009-03-24 23:22:58 -04:00
trace_syscalls.c tracing/syscalls: use a dedicated file header 2009-04-09 05:43:32 +02:00
trace_sysprof.c tracing/ftrace: factorize the tracing files creation 2009-04-07 14:43:07 +02:00
trace_workqueue.c trace_workqueue: remove blank line between each cpu 2009-06-02 01:14:26 +02:00
trace.c tracing: make trace pipe recognize latency format flag 2009-06-01 23:26:02 -04:00
trace.h Merge branch 'tracing/hw-branch-tracing' into tracing/core 2009-05-07 13:36:22 +02:00