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authorSteven Rostedt (Red Hat)2013-03-05 07:30:24 -0500
committerSteven Rostedt2013-03-15 00:34:57 -0400
commit22cffc2bb4a50d8c56f03c56f9f19dea85b78e30 (patch)
tree39f6127ad367843e1a9bc36d8f2efbe00b3072fe
parent873c642f5964b260480850040dec21e42d0ae4e4 (diff)
tracing: Enable snapshot when any latency tracer is enabled
The snapshot utility is extremely useful, and does not add any more overhead in memory when another latency tracer is enabled. They use the snapshot underneath. There's no reason to hide the snapshot file when a latency tracer has been enabled in the kernel. If any of the latency tracers (irq, preempt or wakeup) is enabled then also select the snapshot facility. Note, snapshot can be enabled without the latency tracers enabled. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--kernel/trace/Kconfig3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index b516a8e19d51..590a27fc212f 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -191,6 +191,7 @@ config IRQSOFF_TRACER
select GENERIC_TRACER
select TRACER_MAX_TRACE
select RING_BUFFER_ALLOW_SWAP
+ select TRACER_SNAPSHOT
help
This option measures the time spent in irqs-off critical
sections, with microsecond accuracy.
@@ -213,6 +214,7 @@ config PREEMPT_TRACER
select GENERIC_TRACER
select TRACER_MAX_TRACE
select RING_BUFFER_ALLOW_SWAP
+ select TRACER_SNAPSHOT
help
This option measures the time spent in preemption-off critical
sections, with microsecond accuracy.
@@ -232,6 +234,7 @@ config SCHED_TRACER
select GENERIC_TRACER
select CONTEXT_SWITCH_TRACER
select TRACER_MAX_TRACE
+ select TRACER_SNAPSHOT
help
This tracer tracks the latency of the highest priority task
to be scheduled in, starting from the point it has woken up.