Program Running Time

[cplusplusquestion]

# time ./a.out test.data

the output:

real 0m49.172s
user 0m5.638s
sys 0m4.850s

Why real time and user time have big difference? I've tried to change
a code: for example disable print() function, the real time and user
time closer. How to improve the real time in a program?

[Jerry Coffin]

In article <f7db0716-0e06-4caa-95fc-284130408b44
@l32g2000hse.googlegroups.com>, cp***************@gmail.com says...

# time ./a.out test.data

the output:

real 0m49.172s
user 0m5.638s
sys 0m4.850s

Why real time and user time have big difference? I've tried to change
a code: for example disable print() function, the real time and user
time closer. How to improve the real time in a program?

This basically means your program is I/O bound. Without knowing more
about how that's occurring it's impossible to suggest improvements.
Sometimes, it's just the nature of that particular program (e.g. cat
will almost always be heavily I/O bound).

--
Later,
Jerry.

The universe is a figment of its own imagination.

[jonnyothan]

On Jan 14, 6:18 pm, [e-mail] wrote:

# time ./a.out test.data

the output:

real 0m49.172s
user 0m5.638s
sys 0m4.850s

Why real time and user time have big difference? I've tried to change
a code: for example disable print() function, the real time and user
time closer. How to improve the real time in a program?

http://www.google.com/search?hl=en&q...=Google+Search

The first result would probably be a good place to start.

I wouldn't do anything without a profiler though.

[cplusplusquestion]

On Jan 15, 1:44 pm, [e-mail] wrote:

On Jan 14, 6:18 pm, [e-mail] wrote:

# time ./a.out test.data

the output:

real 0m49.172s
user 0m5.638s
sys 0m4.850s

Why real time and user time have big difference? I've tried to change
a code: for example disable print() function, the real time and user
time closer. How to improve the real time in a program?

http://www.google.com/search?hl=en&q...2B%2B+code&btn...

The first result would probably be a good place to start.

I wouldn't do anything without a profiler though.

Thanks. It's really helpful.