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authorJohn Stultz <john.stultz@linaro.org>2012-07-27 22:48:10 +0400
committerIngo Molnar <mingo@kernel.org>2012-07-31 19:09:12 +0400
commit02ab20ae38337b99b5c29c81090f594b8fd61283 (patch)
treec64ac720c8af5230e4f9e2aa7c56ede8f86b31f3 /include
parenta7ea3bbf5d58f4df2265d312f91d5769eabc8144 (diff)
downloadlinux-02ab20ae38337b99b5c29c81090f594b8fd61283.tar.xz
time/jiffies: Rename ACTHZ to SHIFTED_HZ
Ingo noted that ACTHZ is a confusing name, and requested it be renamed, so this patch renames ACTHZ to SHIFTED_HZ to better describe it. Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Prarit Bhargava <prarit@redhat.com> Link: http://lkml.kernel.org/r/1343414893-45779-3-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/jiffies.h21
-rw-r--r--include/linux/timex.h2
2 files changed, 14 insertions, 9 deletions
diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h
index 7d24466fb80b..82680541576d 100644
--- a/include/linux/jiffies.h
+++ b/include/linux/jiffies.h
@@ -55,21 +55,26 @@
/* 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. ACTHZ is actual HZ ("<< 8" is for accuracy) */
-# define ACTHZ (SH_DIV(CLOCK_TICK_RATE, LATCH, 8))
+/*
+ * 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 ACTHZ (HZ << 8)
+# 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
diff --git a/include/linux/timex.h b/include/linux/timex.h
index 99bc88b1fc02..7c5ceb20e03a 100644
--- a/include/linux/timex.h
+++ b/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);