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authorHauke Mehrtens <hmehrtens@maxlinear.com>2020-12-03 18:49:12 +0100
committerHauke Mehrtens <hauke@hauke-m.de>2020-12-16 22:11:19 +0100
commit1926ffb5ab3ce15e20445f52e6a44a9d9c2295c5 (patch)
treeda5e13b2a91979f2694420146e6de13c064122b1
parent47f30a566e4e76738464c5c7e6a2f7feb4b48410 (diff)
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build: Add IRQSOFF and PREEMPT TRACER kernel config option
This adds the CONFIG_IRQSOFF_TRACER and the CONFIG_PREEMPT_TRACER kernel configuration option to the OpenWrt menu. This can be used to debug latencies in the system. The CONFIG_PREEMPT_TRACER option needs the CONFIG_PREEMPT option which is supposed to be used for Low-Latency Desktop and not used by many targets in OpenWrt. The help text is copied from the Linux kernel Kconfig. Signed-off-by: Hauke Mehrtens <hmehrtens@maxlinear.com>
-rw-r--r--config/Config-kernel.in34
1 files changed, 34 insertions, 0 deletions
diff --git a/config/Config-kernel.in b/config/Config-kernel.in
index 3f013aa2b2..22e2286b8d 100644
--- a/config/Config-kernel.in
+++ b/config/Config-kernel.in
@@ -266,6 +266,40 @@ config KERNEL_FUNCTION_PROFILER
depends on KERNEL_FUNCTION_TRACER
default n
+config KERNEL_IRQSOFF_TRACER
+ bool "Interrupts-off Latency Tracer"
+ depends on KERNEL_FTRACE
+ help
+ This option measures the time spent in irqs-off critical
+ sections, with microsecond accuracy.
+
+ The default measurement method is a maximum search, which is
+ disabled by default and can be runtime (re-)started
+ via:
+
+ echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
+
+ (Note that kernel size and overhead increase with this option
+ enabled. This option and the preempt-off timing option can be
+ used together or separately.)
+
+config KERNEL_PREEMPT_TRACER
+ bool "Preemption-off Latency Tracer"
+ depends on KERNEL_FTRACE
+ help
+ This option measures the time spent in preemption-off critical
+ sections, with microsecond accuracy.
+
+ The default measurement method is a maximum search, which is
+ disabled by default and can be runtime (re-)started
+ via:
+
+ echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
+
+ (Note that kernel size and overhead increase with this option
+ enabled. This option and the irqs-off timing option can be
+ used together or separately.)
+
config KERNEL_DEBUG_KERNEL
bool
default n