---------- 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/$pid/sched) by process in different configurations for my
project work. But I was not able to get the time units for the values
displayed in the file. I tried searching it in source code -
kernel/sched/cputime.c,include/linux/sched.h etc. but it left me more
confused.
Can you please answer me about the measurement units (is it
microseconds, nanoseconds, jiffles ...) ?
Also, I was not able to find proper documentation for /proc/pid/sched.
Please point to me if it's already there. If not, I would love to
contribute toward documenting these variables. It would be very
helpful for newbies (like me) in future.
Thanks,
Best Regards,
Shivank Garg
Hello Shivank,
On Wed, 28 Jul 2021 at 14:59, Shivank Garg [off-list ref] wrote:
---------- Forwarded message ---------
From: Shivank Garg <redacted>
Date: Wed, Jul 28, 2021 at 6:26 PM
Subject: /proc/pid/sched units
To: Linux Kernel Mailing List <redacted>, Linux MM
[off-list ref], [off-list ref]
Hi Everyone,
I'm analyzing the cpu time taken ("se.sum_exec_runtime" in
/proc/$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/
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/