printk: use ktime_get()

printk timestamps: use ktime_get().

Some platforms have a functioning clocksource function only after
they are done with early bootup, so delay this until out of
SYSTEM_BOOTING state.

it's also inherently safe now, as any bugs in this area will be
caught by the printk recursion checks.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 3 insertions, 1 deletions

diff --git a/kernel/printk.c b/kernel/printk.c
index 3b7c968d0ef9..423a8c765a57 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -702,7 +702,9 @@ asmlinkage int vprintk(const char *fmt, va_list args)
                                         loglev_char = default_message_loglevel
                                                 + '0';
                                 }
-                                t = cpu_clock(printk_cpu);
+                                t = 0;
+                                if (system_state != SYSTEM_BOOTING)
+                                        t = ktime_to_ns(ktime_get());
                                 nanosec_rem = do_div(t, 1000000000);
                                 tlen = sprintf(tbuf,
                                                 "<%c>[%5lu.%06lu] ",