Say if I want to find the actual time of 100 jiffies on my linux, how do I do it? Thanks a lot!
c*e
2 楼
As I read it, jiffies are the number of elapsed ticks starting from the system start. It's increment by 1 for every timer interrupt. So that depends on how linux programs the programmable timer. Normally, it's 10ms per tick.
【在 F**e 的大作中提到】 : Say if I want to find the actual time of 100 jiffies on my linux, : how do I do it? : Thanks a lot!
m*e
3 楼
In user space it's ALWAYS 100 jiffies per second (at least on x86). In kernel space it depends. Recent kernels have changed it internally.
【在 c********e 的大作中提到】 : As I read it, jiffies are the number of elapsed ticks starting from : the system start. It's increment by 1 for every timer interrupt. : So that depends on how linux programs the programmable timer. : Normally, it's 10ms per tick.
F*e
4 楼
Thank you, microbe and clarkmouse! Actually my problem was: I was getting process info from /proc//stat One of the properties I am interested in is the usertime(utime) there. The man says utime is "The number of jiffies that this process has been scheduled in user mode". So that means the number I get there divided by 100 will give me the number of seconds? Right? Just want to make sure. Thanks.
【在 m*****e 的大作中提到】 : : In user space it's ALWAYS 100 jiffies per second (at least on x86). : In kernel space it depends. Recent kernels have changed it internally.