Commit 3ce2b920 authored by Frédéric Weisbecker's avatar Frédéric Weisbecker Committed by Ingo Molnar
Browse files

ftrace/fastboot: disable tracers self-tests when boot tracer is selected 



The tracing engine resets the ring buffer and the tracers touch it
too during self-tests. These self-tests happen during tracers registering
and work against boot tracing which is logging initcalls.

We have to disable tracing self-tests if the boot-tracer is selected.

Reported-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 3bf77af6

kernel/trace/Kconfig

+4 −3
Original line number Diff line number Diff line
@@ -126,7 +126,9 @@ config BOOT_TRACER 
	  the timings of the initcalls. Its aim is to be parsed by the

	  /scripts/bootgraph.pl tool to produce pretty graphics about

	  boot inefficiencies, giving a visual representation of the

	  delays during initcalls.

	  delays during initcalls. Note that tracers self tests can't

	  be enabled if this tracer is selected since only one tracer

	  should touch the tracing buffer at a time.



config STACK_TRACER

	bool "Trace max stack"
@@ -168,8 +170,7 @@ config FTRACE_SELFTEST 


config FTRACE_STARTUP_TEST

	bool "Perform a startup test on ftrace"

	depends on TRACING

	depends on DEBUG_KERNEL

	depends on TRACING && DEBUG_KERNEL && !BOOT_TRACER

	select FTRACE_SELFTEST

	help

	  This option performs a series of startup tests on ftrace. On bootup

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