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author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-08-03 10:58:57 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-08-03 10:58:57 -0700 |
commit | ddc5057c1c1fb3e99afeeef45d2b8ff9597e6707 (patch) | |
tree | 801e4842f3a4dce2d777336b54f3caf075975025 /include/linux | |
parent | fcc1d2a9cea4ba97c9800e1de0748003bba07335 (diff) | |
parent | 4e250fdde9be50581c7dd5fed88c9b9960615314 (diff) | |
download | linux-stable-ddc5057c1c1fb3e99afeeef45d2b8ff9597e6707.tar.gz linux-stable-ddc5057c1c1fb3e99afeeef45d2b8ff9597e6707.tar.bz2 linux-stable-ddc5057c1c1fb3e99afeeef45d2b8ff9597e6707.zip |
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/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
Diffstat (limited to 'include/linux')
-rw-r--r-- | include/linux/jiffies.h | 29 | ||||
-rw-r--r-- | include/linux/timex.h | 2 |
2 files changed, 20 insertions, 11 deletions
diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h index 265e2c3cbd1c..82680541576d 100644 --- a/include/linux/jiffies.h +++ b/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 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); |