From f7b382b988233b5851eddf4531651ffe4133e88c Mon Sep 17 00:00:00 2001 From: Abhilash Jindal Date: Sun, 31 Jan 2016 14:29:01 -0500 Subject: [PATCH] PM/freezer: y2038, use boottime to compare tstamps Wall time obtained from do_gettimeofday gives 32 bit timeval which can only represent time until January 2038. This patch moves to ktime_t, a 64-bit time. Also, wall time is susceptible to sudden jumps due to user setting the time or due to NTP. Boot time is constantly increasing time better suited for subtracting two timestamps. Signed-off-by: Abhilash Jindal Acked-by: Pavel Machek Signed-off-by: Rafael J. Wysocki --- kernel/power/process.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/kernel/power/process.c b/kernel/power/process.c index 564f786df470..df058bed53ce 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -30,13 +30,12 @@ static int try_to_freeze_tasks(bool user_only) unsigned long end_time; unsigned int todo; bool wq_busy = false; - struct timeval start, end; - u64 elapsed_msecs64; + ktime_t start, end, elapsed; unsigned int elapsed_msecs; bool wakeup = false; int sleep_usecs = USEC_PER_MSEC; - do_gettimeofday(&start); + start = ktime_get_boottime(); end_time = jiffies + msecs_to_jiffies(freeze_timeout_msecs); @@ -78,10 +77,9 @@ static int try_to_freeze_tasks(bool user_only) sleep_usecs *= 2; } - do_gettimeofday(&end); - elapsed_msecs64 = timeval_to_ns(&end) - timeval_to_ns(&start); - do_div(elapsed_msecs64, NSEC_PER_MSEC); - elapsed_msecs = elapsed_msecs64; + end = ktime_get_boottime(); + elapsed = ktime_sub(end, start); + elapsed_msecs = ktime_to_ms(elapsed); if (todo) { pr_cont("\n"); -- 2.20.1