diff options
Diffstat (limited to 'kernel/time.c')
| -rw-r--r-- | kernel/time.c | 106 |
1 files changed, 12 insertions, 94 deletions
diff --git a/kernel/time.c b/kernel/time.c index 5d4d9a024..27dc71b73 100644 --- a/kernel/time.c +++ b/kernel/time.c @@ -244,41 +244,18 @@ EXPORT_SYMBOL(current_fs_time); /* * Convert jiffies to milliseconds and back. - * - * Avoid unnecessary multiplications/divisions in the - * two most common HZ cases: */ -unsigned int jiffies_to_msecs(const unsigned long j) +unsigned int __jiffies_to_msecs(const unsigned long j) { -#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) - return (MSEC_PER_SEC / HZ) * j; -#elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) - return (j + (HZ / MSEC_PER_SEC) - 1)/(HZ / MSEC_PER_SEC); -#else -# if BITS_PER_LONG == 32 - return (HZ_TO_MSEC_MUL32 * j) >> HZ_TO_MSEC_SHR32; -# else - return (j * HZ_TO_MSEC_NUM) / HZ_TO_MSEC_DEN; -# endif -#endif + return __inline_jiffies_to_msecs(j); } -EXPORT_SYMBOL(jiffies_to_msecs); +EXPORT_SYMBOL(__jiffies_to_msecs); -unsigned int jiffies_to_usecs(const unsigned long j) +unsigned int __jiffies_to_usecs(const unsigned long j) { -#if HZ <= USEC_PER_SEC && !(USEC_PER_SEC % HZ) - return (USEC_PER_SEC / HZ) * j; -#elif HZ > USEC_PER_SEC && !(HZ % USEC_PER_SEC) - return (j + (HZ / USEC_PER_SEC) - 1)/(HZ / USEC_PER_SEC); -#else -# if BITS_PER_LONG == 32 - return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32; -# else - return (j * HZ_TO_USEC_NUM) / HZ_TO_USEC_DEN; -# endif -#endif + return __inline_jiffies_to_usecs(j); } -EXPORT_SYMBOL(jiffies_to_usecs); +EXPORT_SYMBOL(__jiffies_to_usecs); /** * timespec_trunc - Truncate timespec to a granularity @@ -427,76 +404,17 @@ struct timeval ns_to_timeval(const s64 nsec) } EXPORT_SYMBOL(ns_to_timeval); -/* - * When we convert to jiffies then we interpret incoming values - * the following way: - * - * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET) - * - * - 'too large' values [that would result in larger than - * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. - * - * - all other values are converted to jiffies by either multiplying - * the input value by a factor or dividing it with a factor - * - * We must also be careful about 32-bit overflows. - */ -unsigned long msecs_to_jiffies(const unsigned int m) +unsigned long __msecs_to_jiffies(const unsigned int m) { - /* - * Negative value, means infinite timeout: - */ - if ((int)m < 0) - return MAX_JIFFY_OFFSET; - -#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) - /* - * HZ is equal to or smaller than 1000, and 1000 is a nice - * round multiple of HZ, divide with the factor between them, - * but round upwards: - */ - return (m + (MSEC_PER_SEC / HZ) - 1) / (MSEC_PER_SEC / HZ); -#elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) - /* - * HZ is larger than 1000, and HZ is a nice round multiple of - * 1000 - simply multiply with the factor between them. - * - * But first make sure the multiplication result cannot - * overflow: - */ - if (m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) - return MAX_JIFFY_OFFSET; - - return m * (HZ / MSEC_PER_SEC); -#else - /* - * Generic case - multiply, round and divide. But first - * check that if we are doing a net multiplication, that - * we wouldn't overflow: - */ - if (HZ > MSEC_PER_SEC && m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) - return MAX_JIFFY_OFFSET; - - return (MSEC_TO_HZ_MUL32 * m + MSEC_TO_HZ_ADJ32) - >> MSEC_TO_HZ_SHR32; -#endif + return __inline_msecs_to_jiffies(m); } -EXPORT_SYMBOL(msecs_to_jiffies); +EXPORT_SYMBOL(__msecs_to_jiffies); -unsigned long usecs_to_jiffies(const unsigned int u) +unsigned long __usecs_to_jiffies(const unsigned int u) { - if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET)) - return MAX_JIFFY_OFFSET; -#if HZ <= USEC_PER_SEC && !(USEC_PER_SEC % HZ) - return (u + (USEC_PER_SEC / HZ) - 1) / (USEC_PER_SEC / HZ); -#elif HZ > USEC_PER_SEC && !(HZ % USEC_PER_SEC) - return u * (HZ / USEC_PER_SEC); -#else - return (USEC_TO_HZ_MUL32 * u + USEC_TO_HZ_ADJ32) - >> USEC_TO_HZ_SHR32; -#endif + return __inline_usecs_to_jiffies(u); } -EXPORT_SYMBOL(usecs_to_jiffies); +EXPORT_SYMBOL(__usecs_to_jiffies); /* * The TICK_NSEC - 1 rounds up the value to the next resolution. Note |
