From: Frédéric Weisbecker Date: Wed, 24 Sep 2008 09:36:09 +0000 (+0100) Subject: ftrace/fastboot: disable tracers self-tests when boot tracer is selected X-Git-Tag: firefly_0821_release~17186^2~43 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=3ce2b9200da8b7170cc7463b7ee4212fad7b291e;p=firefly-linux-kernel-4.4.55.git 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: Ingo Molnar Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 81a17ef6b942..4feb3c81f94d 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -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