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From: Tom Zanussi <tom.zanussi@linux.intel.com>
To: rostedt@goodmis.org
Cc: tglx@linutronix.de, mhiramat@kernel.org, namhyung@kernel.org,
	vedang.patel@intel.com, bigeasy@linutronix.de,
	joel.opensrc@gmail.com, joelaf@google.com,
	mathieu.desnoyers@efficios.com, baohong.liu@intel.com,
	rajvi.jingar@intel.com, julia@ni.com,
	linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org,
	Tom Zanussi <tom.zanussi@linux.intel.com>
Subject: [PATCH v4 35/37] tracing: Increase trace_recursive_lock() limit for synthetic events
Date: Mon, 30 Oct 2017 15:52:17 -0500	[thread overview]
Message-ID: <b0c2255848f22ab923550f6f19d8802cf3084e64.1509395596.git.tom.zanussi@linux.intel.com> (raw)
In-Reply-To: <cover.1509395595.git.tom.zanussi@linux.intel.com>
In-Reply-To: <cover.1509395595.git.tom.zanussi@linux.intel.com>

Synthetic event generation needs to happen while the current event is
still in progress, so add 1 to the trace_recursive_lock() recursion
limit to account for that.

Because we also want to allow for the possibility of a synthetic event
being generated from another synthetic event, add an additional
increment for that as well.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
---
 kernel/trace/ring_buffer.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index ab7b65d..39f1ca0 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2589,16 +2589,16 @@ static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer,
  *  IRQ context
  *  NMI context
  *
- * If for some reason the ring buffer starts to recurse, we
- * only allow that to happen at most 4 times (one for each
- * context). If it happens 5 times, then we consider this a
- * recusive loop and do not let it go further.
+ * If for some reason the ring buffer starts to recurse, we only allow
+ * that to happen at most 6 times (one for each context, plus possibly
+ * two levels of synthetic event generation). If it happens 7 times,
+ * then we consider this a recusive loop and do not let it go further.
  */
 
 static __always_inline int
 trace_recursive_lock(struct ring_buffer_per_cpu *cpu_buffer)
 {
-	if (cpu_buffer->current_context >= 4)
+	if (cpu_buffer->current_context >= 6)
 		return 1;
 
 	cpu_buffer->current_context++;
-- 
1.9.3

  parent reply	other threads:[~2017-10-30 20:55 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-10-30 20:51 [PATCH v4 00/37] tracing: Inter-event (e.g. latency) support Tom Zanussi
2017-10-30 20:51 ` [PATCH v4 01/37] tracing: Move hist trigger Documentation to histogram.txt Tom Zanussi
2017-10-30 20:51 ` [PATCH v4 02/37] tracing: Add Documentation for log2 modifier Tom Zanussi
2017-10-30 20:51 ` [PATCH v4 03/37] tracing: Add support to detect and avoid duplicates Tom Zanussi
2017-10-30 20:51 ` [PATCH v4 04/37] tracing: Remove code which merges duplicates Tom Zanussi
2017-10-30 20:51 ` [PATCH v4 05/37] ring-buffer: Add interface for setting absolute time stamps Tom Zanussi
2017-10-30 20:51 ` [PATCH v4 06/37] ring-buffer: Redefine the unimplemented RINGBUF_TYPE_TIME_STAMP Tom Zanussi
2017-11-06  5:09   ` Namhyung Kim
2017-11-06 15:52     ` Tom Zanussi
2017-10-30 20:51 ` [PATCH v4 07/37] tracing: Add timestamp_mode trace file Tom Zanussi
2017-10-30 20:51 ` [PATCH v4 08/37] tracing: Give event triggers access to ring_buffer_event Tom Zanussi
2017-10-30 20:51 ` [PATCH v4 09/37] tracing: Add ring buffer event param to hist field functions Tom Zanussi
2017-10-30 20:51 ` [PATCH v4 10/37] tracing: Break out hist trigger assignment parsing Tom Zanussi
2017-10-30 20:51 ` [PATCH v4 11/37] tracing: Add hist trigger timestamp support Tom Zanussi
2017-10-30 20:51 ` [PATCH v4 12/37] tracing: Add per-element variable support to tracing_map Tom Zanussi
2017-10-30 20:51 ` [PATCH v4 13/37] tracing: Add hist_data member to hist_field Tom Zanussi
2017-10-30 20:51 ` [PATCH v4 14/37] tracing: Add usecs modifier for hist trigger timestamps Tom Zanussi
2017-10-30 20:51 ` [PATCH v4 15/37] tracing: Add variable support to hist triggers Tom Zanussi
2017-10-30 20:51 ` [PATCH v4 16/37] tracing: Account for variables in named trigger compatibility Tom Zanussi
2017-10-30 20:51 ` [PATCH v4 17/37] tracing: Move get_hist_field_flags() Tom Zanussi
2017-10-30 20:52 ` [PATCH v4 18/37] tracing: Add simple expression support to hist triggers Tom Zanussi
2017-10-30 20:52 ` [PATCH v4 19/37] tracing: Generalize per-element hist trigger data Tom Zanussi
2017-10-30 20:52 ` [PATCH v4 20/37] tracing: Pass tracing_map_elt to hist_field accessor functions Tom Zanussi
2017-10-30 20:52 ` [PATCH v4 21/37] tracing: Add hist_field 'type' field Tom Zanussi
2017-10-30 20:52 ` [PATCH v4 22/37] tracing: Add variable reference handling to hist triggers Tom Zanussi
2017-10-30 20:52 ` [PATCH v4 23/37] tracing: Add hist trigger action hook Tom Zanussi
2017-10-30 20:52 ` [PATCH v4 24/37] tracing: Add support for 'synthetic' events Tom Zanussi
2017-10-30 20:52 ` [PATCH v4 25/37] tracing: Add support for 'field variables' Tom Zanussi
2017-10-30 20:52 ` [PATCH v4 26/37] tracing: Add 'onmatch' hist trigger action support Tom Zanussi
2017-10-30 20:52 ` [PATCH v4 27/37] tracing: Add 'onmax' " Tom Zanussi
2017-10-30 20:52 ` [PATCH v4 28/37] tracing: Allow whitespace to surround hist trigger filter Tom Zanussi
2017-10-30 20:52 ` [PATCH v4 29/37] tracing: Add cpu field for hist triggers Tom Zanussi
2017-10-30 20:52 ` [PATCH v4 30/37] tracing: Add hist trigger support for variable reference aliases Tom Zanussi
2017-10-30 20:52 ` [PATCH v4 31/37] tracing: Add 'last error' error facility for hist triggers Tom Zanussi
2017-10-30 20:52 ` [PATCH v4 32/37] tracing: Add inter-event hist trigger Documentation Tom Zanussi
2017-10-30 20:52 ` [PATCH v4 33/37] tracing: Make tracing_set_clock() non-static Tom Zanussi
2017-10-30 20:52 ` [PATCH v4 34/37] tracing: Add a clock attribute for hist triggers Tom Zanussi
2017-10-30 20:52 ` Tom Zanussi [this message]
2017-10-30 20:52 ` [PATCH v4 36/37] tracing: Add inter-event blurb to HIST_TRIGGERS config option Tom Zanussi
2017-10-30 20:52 ` [PATCH v4 37/37] selftests: ftrace: Add inter-event hist triggers testcases Tom Zanussi
2017-10-31 14:29   ` Masami Hiramatsu
2017-10-31 20:40     ` Jingar, Rajvi

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