Linux内核中有个全局变量jiffies,用来记录系统自启动以来的运行的节拍数,系统在启动时会将jiffies初始化为0,变量会根据节拍率自增。jiffies的定义在内核文件include/linux/jiffies.h中 extern u64 __jiffy_data jiffies_64; extern unsigned long volatile __jiffy_data jiffies; 可以从数据类型看出来,其中第一个是...
函数名称:Convert jiffies to milliseconds and back.* Avoid unnecessary multiplications/divisions in the* two most common HZ cases: 返回类型:unsigned int 参数: 类型参数名称 const unsigned longj 377返回:Parameters used to convert the timespec values:除HZ乘j ...
由于jiffies是一个无符号长整型(unsigned long),它有一个最大值(MAX_JIFFY_OFFSET),因此msecs_to_jiffies函数可能会对非常大的毫秒数进行截断。 HZ是内核中的一个配置选项,表示每秒的时钟中断次数。HZ的值会影响jiffies的精度,从而影响msecs_to_jiffies的转换结果。 在进行时间相关的编程时,了解jiffies和msecs_to_j...
Name: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: Proto:static inline unsigned long _msecs_to_jiffies(const unsigned int m) Type:unsigned long Parameter: TypeParameterName const unsigned int m 311...
+ >> MSEC_TO_HZ_SHR32; +#endif + } else + return __msecs_to_jiffies(m); +} + extern unsigned long usecs_to_jiffies(const unsigned int u); extern unsigned long timespec_to_jiffies(const struct timespec *value); extern void jiffies_to_timespec(const unsigned long jiffies, ...
函数名称:msecs_to_jiffies: - convert milliseconds to jiffies*@m: time in milliseconds* conversion is done as follows:* - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET)* - 'too large' values [that would result in larger than ...