diff options
| -rw-r--r-- | kernel/trace/Kconfig | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 590a27fc212f..f78eab251897 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -192,6 +192,7 @@ config IRQSOFF_TRACER select TRACER_MAX_TRACE select RING_BUFFER_ALLOW_SWAP select TRACER_SNAPSHOT + select TRACER_SNAPSHOT_PER_CPU_SWAP help This option measures the time spent in irqs-off critical sections, with microsecond accuracy. @@ -215,6 +216,7 @@ config PREEMPT_TRACER select TRACER_MAX_TRACE select RING_BUFFER_ALLOW_SWAP select TRACER_SNAPSHOT + select TRACER_SNAPSHOT_PER_CPU_SWAP help This option measures the time spent in preemption-off critical sections, with microsecond accuracy. @@ -266,6 +268,27 @@ config TRACER_SNAPSHOT echo 1 > /sys/kernel/debug/tracing/snapshot cat snapshot +config TRACER_SNAPSHOT_PER_CPU_SWAP + bool "Allow snapshot to swap per CPU" + depends on TRACER_SNAPSHOT + select RING_BUFFER_ALLOW_SWAP + help + Allow doing a snapshot of a single CPU buffer instead of a + full swap (all buffers). If this is set, then the following is + allowed: + + echo 1 > /sys/kernel/debug/tracing/per_cpu/cpu2/snapshot + + After which, only the tracing buffer for CPU 2 was swapped with + the main tracing buffer, and the other CPU buffers remain the same. + + When this is enabled, this adds a little more overhead to the + trace recording, as it needs to add some checks to synchronize + recording with swaps. But this does not affect the performance + of the overall system. This is enabled by default when the preempt + or irq latency tracers are enabled, as those need to swap as well + and already adds the overhead (plus a lot more). + config TRACE_BRANCH_PROFILING bool select GENERIC_TRACER |