diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/jiffies.h | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h index 9527ddbb0f1b..5e75af6cf1bc 100644 --- a/include/linux/jiffies.h +++ b/include/linux/jiffies.h @@ -343,12 +343,24 @@ static inline unsigned long _msecs_to_jiffies(const unsigned int m) * handling any 32-bit overflows. * for the details see __msecs_to_jiffies() * - * the HZ range specific helpers _msecs_to_jiffies() are called from - * __msecs_to_jiffies(). + * msecs_to_jiffies() checks for the passed in value being a constant + * via __builtin_constant_p() allowing gcc to eliminate most of the + * code, __msecs_to_jiffies() is called if the value passed does not + * allow constant folding and the actual conversion must be done at + * runtime. + * the HZ range specific helpers _msecs_to_jiffies() are called both + * directly here and from __msecs_to_jiffies() in the case where + * constant folding is not possible. */ static inline unsigned long msecs_to_jiffies(const unsigned int m) { - return __msecs_to_jiffies(m); + if (__builtin_constant_p(m)) { + if ((int)m < 0) + return MAX_JIFFY_OFFSET; + return _msecs_to_jiffies(m); + } else { + return __msecs_to_jiffies(m); + } } extern unsigned long usecs_to_jiffies(const unsigned int u); |
