printk.time=1/CONFIG_PRINTK_TIME=1 adds a unmodified local hardware clock timestamp to printk messages. The local hardware clock loses time each day making it difficult to determine exactly when an issue has occurred in the kernel log, and making it difficult to determine how kernel and hardware issues relate to each other in real time.
Add monotonic, boottime, and real clock timestamps in addition to the existing local hardware clock timestamp. Signed-off-by: Prarit Bhargava <[email protected]> Cc: Mark Salyzyn <[email protected]> Cc: Jonathan Corbet <[email protected]> Cc: Petr Mladek <[email protected]> Cc: Sergey Senozhatsky <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: John Stultz <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Stephen Boyd <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: "Paul E. McKenney" <[email protected]> Cc: Christoffer Dall <[email protected]> Cc: Deepa Dinamani <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Joel Fernandes <[email protected]> Cc: Prarit Bhargava <[email protected]> Cc: Kees Cook <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: "Luis R. Rodriguez" <[email protected]> Cc: Nicholas Piggin <[email protected]> Cc: "Jason A. Donenfeld" <[email protected]> Cc: Olof Johansson <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: [email protected] [jstultz: reworked Kconfig settings to avoid defconfig noise] Signed-off-by: John Stultz <[email protected]> Prarit Bhargava (2): time: Make fast functions return 0 before timekeeping is initialized printk: Add monotonic, boottime, and realtime timestamps Documentation/admin-guide/kernel-parameters.txt | 6 +- include/linux/timekeeping.h | 1 + kernel/printk/printk.c | 142 +++++++++++++++++++++++- kernel/time/timekeeping.c | 54 +++++++-- lib/Kconfig.debug | 65 ++++++++++- 5 files changed, 249 insertions(+), 19 deletions(-) -- 1.8.5.5
