From d59158162e032917a428704160a2063a02405ec6 Mon Sep 17 00:00:00 2001 From: Joel Fernandes Date: Tue, 10 Oct 2017 15:51:37 -0700 Subject: tracing: Add support for preempt and irq enable/disable events Preempt and irq trace events can be used for tracing the start and end of an atomic section which can be used by a trace viewer like systrace to graphically view the start and end of an atomic section and correlate them with latencies and scheduling issues. This also serves as a prelude to using synthetic events or probes to rewrite the preempt and irqsoff tracers, along with numerous benefits of using trace events features for these events. Link: http://lkml.kernel.org/r/20171006005432.14244-3-joelaf@google.com Link: http://lkml.kernel.org/r/20171010225137.17370-1-joelaf@google.com Cc: Peter Zilstra Cc: kernel-team@android.com Signed-off-by: Joel Fernandes Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/Kconfig | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'kernel/trace/Kconfig') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 434c840e2d82..b8395a020821 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -160,6 +160,17 @@ config FUNCTION_GRAPH_TRACER address on the current task structure into a stack of calls. +config PREEMPTIRQ_EVENTS + bool "Enable trace events for preempt and irq disable/enable" + select TRACE_IRQFLAGS + depends on DEBUG_PREEMPT || !PROVE_LOCKING + default n + help + Enable tracing of disable and enable events for preemption and irqs. + For tracing preempt disable/enable events, DEBUG_PREEMPT must be + enabled. For tracing irq disable/enable events, PROVE_LOCKING must + be disabled. + config IRQSOFF_TRACER bool "Interrupts-off Latency Tracer" default n -- cgit v1.3-8-gc7d7 From c5c1ea75a352c3864c4891f36155287a2ed73928 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Tue, 13 Jun 2017 13:06:59 +0200 Subject: tracing: Kconfig text fixes for CONFIG_HWLAT_TRACER Trivial spelling fixes for Kconfig help text of config HWLAT_TRACER. Fixes: e7c15cd8a113 ("tracing: Added hardware latency tracer") Signed-off-by: Jesper Dangaard Brouer Acked-by: Steven Rostedt Signed-off-by: Jiri Kosina --- kernel/trace/Kconfig | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/trace/Kconfig') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 434c840e2d82..f54b7b6b4a4b 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -224,7 +224,7 @@ config HWLAT_TRACER select GENERIC_TRACER help This tracer, when enabled will create one or more kernel threads, - depening on what the cpumask file is set to, which each thread + depending on what the cpumask file is set to, which each thread spinning in a loop looking for interruptions caused by something other than the kernel. For example, if a System Management Interrupt (SMI) takes a noticeable amount of @@ -239,7 +239,7 @@ config HWLAT_TRACER iteration A kernel thread is created that will spin with interrupts disabled - for "width" microseconds in every "widow" cycle. It will not spin + for "width" microseconds in every "window" cycle. It will not spin for "window - width" microseconds, where the system can continue to operate. -- cgit v1.3-8-gc7d7