Hi,

Thanks for the help. My confusion is clear now.

On Sat, Jul 31, 2021 at 3:11 AM Michael Kerrisk (man-pages)
[off-list ref] wrote:

Hello Shivank,

On Wed, 28 Jul 2021 at 14:59, Shivank Garg [off-list ref] wrote:

quoted

---------- Forwarded message ---------
From: Shivank Garg <redacted>
Date: Wed, Jul 28, 2021 at 6:26 PM
Subject: /proc/pid/sched units
To: Linux Kernel Mailing List <redacted>, Linux MM
[off-list ref], [off-list ref]


Hi Everyone,

I'm analyzing the cpu time taken ("se.sum_exec_runtime" in
/proc/$pid/sched) by process in different configurations for my
project work. But I was not able to get the time units for the values
displayed in the file. I tried searching it in source code -
kernel/sched/cputime.c,include/linux/sched.h etc. but it left me more
confused.

Can you please answer me about the measurement units (is it
microseconds, nanoseconds, jiffles ...) ?

Also, I was not able to find proper documentation for /proc/pid/sched.
Please point to me if it's already there. If not, I would love to
contribute toward documenting these variables. It would be very
helpful for newbies (like me) in future.

It looks like se.sum_exec_runtime is milliseconds. In
kernel/sched/debug.c, see proc_sched_show_task(), the definition of
the PN() PNS(), and SPLIT_NS() macros, and the nsec_high(x) and
nsec_low(x) functions.

Thanks,

Michael


--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/