Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/sc…

…m/linux/kernel/git/tip/tip

Pull timer fixes from Ingo Molnar:
 "One regression fix, and a couple of cleanups that clean up the code
  flow in areas that had high-profile bugs recently."

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: Remove all direct references to timekeeper
  time: Clean up offs_real/wall_to_mono and offs_boot/total_sleep_time updates
  time: Clean up stray newlines
  time/jiffies: Rename ACTHZ to SHIFTED_HZ
  time/jiffies: Allow CLOCK_TICK_RATE to be undefined
  time: Fix casting issue in tk_set_xtime and tk_xtime_add

include/linux/jiffies.h

@@ -39,9 +39,6 @@
 # error Invalid value of HZ.
 #endif
 
-/* LATCH is used in the interval timer and ftape setup. */
-#define LATCH  ((CLOCK_TICK_RATE + HZ/2) / HZ)	/* For divider */
-
 /* Suppose we want to divide two numbers NOM and DEN: NOM/DEN, then we can
  * improve accuracy by shifting LSH bits, hence calculating:
  *     (NOM << LSH) / DEN
@@ -54,18 +51,30 @@
 #define SH_DIV(NOM,DEN,LSH) (   (((NOM) / (DEN)) << (LSH))              \
                              + ((((NOM) % (DEN)) << (LSH)) + (DEN) / 2) / (DEN))
 
-/* HZ is the requested value. ACTHZ is actual HZ ("<< 8" is for accuracy) */
-#define ACTHZ (SH_DIV (CLOCK_TICK_RATE, LATCH, 8))
+#ifdef CLOCK_TICK_RATE
+/* LATCH is used in the interval timer and ftape setup. */
+# define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ)	/* For divider */
+
+/*
+ * HZ is the requested value. However the CLOCK_TICK_RATE may not allow
+ * for exactly HZ. So SHIFTED_HZ is high res HZ ("<< 8" is for accuracy)
+ */
+# define SHIFTED_HZ (SH_DIV(CLOCK_TICK_RATE, LATCH, 8))
+#else
+# define SHIFTED_HZ (HZ << 8)
+#endif
 
-/* TICK_NSEC is the time between ticks in nsec assuming real ACTHZ */
-#define TICK_NSEC (SH_DIV (1000000UL * 1000, ACTHZ, 8))
+/* TICK_NSEC is the time between ticks in nsec assuming SHIFTED_HZ */
+#define TICK_NSEC (SH_DIV(1000000UL * 1000, SHIFTED_HZ, 8))
 
 /* TICK_USEC is the time between ticks in usec assuming fake USER_HZ */
 #define TICK_USEC ((1000000UL + USER_HZ/2) / USER_HZ)
 
-/* TICK_USEC_TO_NSEC is the time between ticks in nsec assuming real ACTHZ and	*/
-/* a value TUSEC for TICK_USEC (can be set bij adjtimex)		*/
-#define TICK_USEC_TO_NSEC(TUSEC) (SH_DIV (TUSEC * USER_HZ * 1000, ACTHZ, 8))
+/*
+ * TICK_USEC_TO_NSEC is the time between ticks in nsec assuming SHIFTED_HZ and
+ * a value TUSEC for TICK_USEC (can be set bij adjtimex)
+ */
+#define TICK_USEC_TO_NSEC(TUSEC) (SH_DIV(TUSEC * USER_HZ * 1000, SHIFTED_HZ, 8))
 
 /* some arch's have a small-data section that can be accessed register-relative
  * but that can only take up to, say, 4-byte variables. jiffies being part of

include/linux/timex.h

@@ -232,7 +232,7 @@ struct timex {
  * estimated error = NTP dispersion.
  */
 extern unsigned long tick_usec;		/* USER_HZ period (usec) */
-extern unsigned long tick_nsec;		/* ACTHZ          period (nsec) */
+extern unsigned long tick_nsec;		/* SHIFTED_HZ period (nsec) */
 
 extern void ntp_init(void);
 extern void ntp_clear(void);

kernel/time/jiffies.c

@@ -37,7 +37,7 @@
  * requested HZ value. It is also not recommended
  * for "tick-less" systems.
  */
-#define NSEC_PER_JIFFY	((u32)((((u64)NSEC_PER_SEC)<<8)/ACTHZ))
+#define NSEC_PER_JIFFY	((u32)((((u64)NSEC_PER_SEC)<<8)/SHIFTED_HZ))
 
 /* Since jiffies uses a simple NSEC_PER_JIFFY multiplier
  * conversion, the .shift value could be zero. However

kernel/time/ntp.c

@@ -28,7 +28,7 @@ DEFINE_SPINLOCK(ntp_lock);
 /* USER_HZ period (usecs): */
 unsigned long			tick_usec = TICK_USEC;
 
-/* ACTHZ period (nsecs): */
+/* SHIFTED_HZ period (nsecs): */
 unsigned long			tick_nsec;
 
 static u64			tick_length;