printk: Add sleep time to timestamps

cpu_clock() uses monotonic time, which skews when the system suspends, making it difficult to interpret kmsg timestamps. Add the sleep time offset to cpu_clock() in order to make kmsg timestamps reflect the actual boot time. Change-Id: I642cc458b4aba8c78e64dbca8febdf8190a328bc Signed-off-by: Sultanxda <[email protected]> Signed-off-by: Nathan Chancellor <[email protected]> Signed-off-by: Danny Lin <[email protected]> Signed-off-by: NotZeetaa <[email protected]>
TIMISONG-dev · Dec 13, 2023 · e9eb5ab · e9eb5ab
1 parent 35f0629
commit e9eb5ab
Show file tree

Hide file tree

Showing 3 changed files with 13 additions and 0 deletions.
diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h
@@ -316,4 +316,6 @@ static inline struct timespec64 get_monotonic_coarse64(void)
 	return ts;
 }
 
+s64 get_total_sleep_time_nsec(void);
+
 #endif
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
@@ -1265,6 +1265,7 @@ static size_t print_time(u64 ts, char *buf)
 	if (!buf)
 		return snprintf(NULL, 0, "[%5lu.000000] ", (unsigned long)ts);
 
+	ts += get_total_sleep_time_nsec();
 	return sprintf(buf, "[%5lu.%06lu] ",
 		       (unsigned long)ts, rem_nsec / 1000);
 }

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
@@ -2417,3 +2417,13 @@ void xtime_update(unsigned long ticks)
 	write_sequnlock(&jiffies_lock);
 	update_wall_time();
 }
+
+/**
+ * get_total_sleep_time_nsec() - returns total sleep time in nanoseconds
+ */
+s64 get_total_sleep_time_nsec(void)
+{
+	struct timekeeper *tk = &tk_core.timekeeper;
+
+	return ktime_to_ns(tk->offs_boot);
+}
-Original file line number
+Diff line change
@@ Expand Up @@
     	return ts;
     }
+    s64 get_total_sleep_time_nsec(void);
     #endif