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. Changes from v12: In 1/3 remove typecast. In 3/3, Reword Kconfig names, simplify timestamp logic and remove recursive code. Signed-off-by: Prarit Bhargava <prarit@xxxxxxxxxx> Cc: Mark Salyzyn <salyzyn@xxxxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Petr Mladek <pmladek@xxxxxxxx> Cc: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: John Stultz <john.stultz@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Stephen Boyd <sboyd@xxxxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> Cc: Christoffer Dall <cdall@xxxxxxxxxx> Cc: Deepa Dinamani <deepa.kernel@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Joel Fernandes <joelaf@xxxxxxxxxx> Cc: Prarit Bhargava <prarit@xxxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Cc: "Luis R. Rodriguez" <mcgrof@xxxxxxxxxx> Cc: Nicholas Piggin <npiggin@xxxxxxxxx> Cc: "Jason A. Donenfeld" <Jason@xxxxxxxxx> Cc: Olof Johansson <olof@xxxxxxxxx> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Cc: linux-doc@xxxxxxxxxxxxxxx [jstultz: reworked Kconfig settings to avoid defconfig noise] Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx> Prarit Bhargava (2): time: Make fast functions return 0 before timekeeping is initialized printk: Add monotonic, boottime, and realtime timestamps Thomas Gleixner (1): timekeeping: Provide NMI safe access to clock realtime Documentation/admin-guide/kernel-parameters.txt | 6 +- include/linux/timekeeper_internal.h | 6 +- include/linux/timekeeping.h | 1 + kernel/printk/printk.c | 130 +++++++++++++++++++++++- kernel/time/timekeeping.c | 60 +++++++++-- lib/Kconfig.debug | 48 ++++++++- 6 files changed, 233 insertions(+), 18 deletions(-) -- 1.8.5.5 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html