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Commit 02ab20ae authored by John Stultz's avatar John Stultz Committed by Ingo Molnar
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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: default avatarJohn 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: default avatarIngo Molnar <mingo@kernel.org>
parent a7ea3bbf

include/linux/jiffies.h

+13 −8
Original line number Diff line number Diff line
@@ -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

include/linux/timex.h

+1 −1
Original line number Diff line number Diff line
@@ -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

+1 −1
Original line number Diff line number Diff line
@@ -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

+1 −1
Original line number Diff line number Diff line
@@ -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;