From 77372afbe06d60c8700c5466824396c72e312cb1 Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Mon, 29 Jul 2019 23:47:04 +0900
Subject: [PATCH] time-util: introduce jiffies_to_usec()

---
 src/basic/time-util.c | 16 +++++++++++++---
 src/basic/time-util.h |  3 ++-
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/src/basic/time-util.c b/src/basic/time-util.c
index 434159f41ce..e13361463be 100644
--- a/src/basic/time-util.c
+++ b/src/basic/time-util.c
@@ -1414,8 +1414,8 @@ struct tm *localtime_or_gmtime_r(const time_t *t, struct tm *tm, bool utc) {
         return utc ? gmtime_r(t, tm) : localtime_r(t, tm);
 }
 
-unsigned long usec_to_jiffies(usec_t u) {
-        static thread_local unsigned long hz = 0;
+static uint32_t sysconf_clock_ticks_cached(void) {
+        static thread_local uint32_t hz = 0;
         long r;
 
         if (hz == 0) {
@@ -1425,7 +1425,17 @@ unsigned long usec_to_jiffies(usec_t u) {
                 hz = r;
         }
 
-        return DIV_ROUND_UP(u , USEC_PER_SEC / hz);
+        return hz;
+}
+
+uint32_t usec_to_jiffies(usec_t u) {
+        uint32_t hz = sysconf_clock_ticks_cached();
+        return DIV_ROUND_UP(u, USEC_PER_SEC / hz);
+}
+
+usec_t jiffies_to_usec(uint32_t j) {
+        uint32_t hz = sysconf_clock_ticks_cached();
+        return DIV_ROUND_UP(j * USEC_PER_SEC, hz);
 }
 
 usec_t usec_shift_clock(usec_t x, clockid_t from, clockid_t to) {
diff --git a/src/basic/time-util.h b/src/basic/time-util.h
index e3a529d9709..4c371257e33 100644
--- a/src/basic/time-util.h
+++ b/src/basic/time-util.h
@@ -136,7 +136,8 @@ int get_timezone(char **timezone);
 time_t mktime_or_timegm(struct tm *tm, bool utc);
 struct tm *localtime_or_gmtime_r(const time_t *t, struct tm *tm, bool utc);
 
-unsigned long usec_to_jiffies(usec_t usec);
+uint32_t usec_to_jiffies(usec_t usec);
+usec_t jiffies_to_usec(uint32_t jiffies);
 
 bool in_utc_timezone(void);