From 9c5b9d3d65e485826fb935453f01171b1a337aa8 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Sat, 11 Jan 2020 01:06:17 +0900 Subject: tracing/boot: Add boot-time tracing Setup tracing options via extra boot config in addition to kernel command line. This adds following commands support. These are applied to the global trace instance. - ftrace.options = OPT1[,OPT2...] Enable given ftrace options. - ftrace.trace_clock = CLOCK Set given CLOCK to ftrace's trace_clock. - ftrace.buffer_size = SIZE Configure ftrace buffer size to SIZE. You can use "KB" or "MB" for that SIZE. - ftrace.events = EVENT[, EVENT2...] Enable given events on boot. You can use a wild card in EVENT. - ftrace.tracer = TRACER Set TRACER to current tracer on boot. (e.g. function) Note that this is NOT replacing the kernel parameters, because this boot config based setting is later than that. If you want to trace earlier boot events, you still need kernel parameters. Link: http://lkml.kernel.org/r/157867237723.17873.17494943526320587488.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/Kconfig | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'kernel/trace/Kconfig') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 25a0fcfa7a5d..75326d8ab1af 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -814,6 +814,15 @@ config GCOV_PROFILE_FTRACE Note that on a kernel compiled with this config, ftrace will run significantly slower. +config BOOTTIME_TRACING + bool "Boot-time Tracing support" + depends on BOOT_CONFIG && TRACING + default y + help + Enable developer to setup ftrace subsystem via supplemental + kernel cmdline at boot time for debugging (tracing) driver + initialization and boot process. + endif # FTRACE endif # TRACING_SUPPORT -- cgit