how does filesystem benchmark tools measure time?
Question
I want to measure the running time of a specific system call, for example, I want to know a pread
need how many time on both CPU and I/O.
Which function should I use?
Now I usetimes
, and it works.
gettimeofday
is get the current time, and that may not just calculate the running time of a specific process, right?
clock
is return the CPU time this program used so far, does this include the I/O time? If there are other programs running, will this influence the time of this function? I mean something like switching running process.
getrusage
seems like a ideal one, but it also returns the CPU
time of a specific process.
Does anyone know how benchmark tools like iozone calculate system calls
time? I've read its code, and still have no idea.
No correct solution
OTHER TIPS
You're looking for times(2)
.