Meaning of entries in /proc/pid/cpu

sun_sun · 11-21-2007, 11:20 PM

hi,

can anyone tell me the meaning of entries in /proc/pid/cpu.

i see something like:
cpu 176787 14
cpu0 16732 7
cpu1 3542 3

Please tel me how to read this lines.

need this ASAP..

thanks in advance..
sun

ta0kira · 11-21-2007, 11:38 PM

man proc is about as ASAP as you can get.
ta0kira

EDIT: That path doesn't exist on my system or in the proc manual.

sun_sun · 11-22-2007, 12:47 AM

Quote:

Originally Posted by ta0kira

man proc is about as ASAP as you can get.
ta0kira

EDIT: That path doesn't exist on my system or in the proc manual.

Yeah..
but man proc doesn't quite clearly explain the meaning of these entries,
i want to know what is cpu0/1/2 and the nos in front of them...

PS : u'll not find this path in ur sytem..as pid has to be some no of the process running ...u can see this like ..when u run something like ..pid = 897 ..then there'll be an entry in /proc/897/..

b0uncer · 11-22-2007, 01:15 AM

Quote:

Originally Posted by sun_sun

PS : u'll not find this path in ur sytem..as pid has to be some no of the process running ...u can see this like ..when u run something like ..pid = 897 ..then there'll be an entry in /proc/897/..

There are always some processes running (check 'top' or 'ps'), so it can't be that.

I guess cpu0 and cpu1 could refer to two processing units, do you have a dualcore cpu or something? I could be wrong, though.. The whole /proc filesystem is a peek hole into the kernel, so if it's not present on somebody's system, it could be that functionality is disabled in that kernel then, and enabled in yours. Guesses, but still.

sun_sun · 11-22-2007, 06:20 AM

Quote:

Originally Posted by b0uncer

There are always some processes running (check 'top' or 'ps'), so it can't be that.

I guess cpu0 and cpu1 could refer to two processing units, do you have a dualcore cpu or something? I could be wrong, though.. The whole /proc filesystem is a peek hole into the kernel, so if it's not present on somebody's system, it could be that functionality is disabled in that kernel then, and enabled in yours. Guesses, but still.

what do the nos mean ??
want to know that too..

ta0kira · 11-22-2007, 09:00 AM

Quote:

Originally Posted by sun_sun

PS : u'll not find this path in ur sytem..as pid has to be some no of the process running ...u can see this like ..when u run something like ..pid = 897 ..then there'll be an entry in /proc/897/..

Yes, I took that into account. I don't have a cpu entry in any process folder, and in fact don't have any entry named cpu anywhere in /proc.
ta0kira

sun_sun · 11-22-2007, 11:19 AM

Quote:

Originally Posted by ta0kira

Yes, I took that into account. I don't have a cpu entry in any process folder, and in fact don't have any entry named cpu anywhere in /proc.
ta0kira

boss..when a process with pid=897 runs, then during the run, you'll see /proc/897/cpu..if you do "cat /proc/897/cpu" -- then you'll see the nos as i mentioned above...only during the process is running..

ta0kira · 11-22-2007, 02:12 PM

Yes, I'm aware of the fact that all processes have their directories in /proc, but even if I do ls /proc/self/cpu, ls /proc/*/cpu, or find /proc -name cpu I get nothing. There are literally no entries in my entire /proc tree which are labeled "cpu".
ta0kira

Alien_Hominid · 11-22-2007, 04:15 PM

Which distro are you running?

ta0kira · 11-22-2007, 05:09 PM

Slackware 12.0, kernel 2.6.21.5.
ta0kira

osor · 11-22-2007, 10:23 PM

Okay, let’s clear some things up…

It’s quite rude of anyone with any problem to go to a free forum and demand an answer ASAP.
There are very few situations where the need to know the information provided by /proc entries could be considered urgent at all.
If the OP did think this was such an urgent problem, the OP could have given more information (e.g., kernel version).
/proc/$PID/cpu is an entry on 2.4 kernels with CONFIG_SMP enabled

Upon reading from /proc/$PID/cpu on such kernels, the output is as follows:

Code:

cpu total_user_time total_system_time
cpu0 user_time_on_cpu0 system_time_on_cpu0
cpu1 user_time_on_cpu1 system_time_on_cpu1
cpu2 user_time_on_cpu2 system_time_on_cpu2
⋮

for as many “cpus” recognized by the kernel.

Alien_Hominid · 11-22-2007, 11:02 PM

Quote:

Originally Posted by ta0kira

Slackware 12.0, kernel 2.6.21.5.
ta0kira

I was asking sun_sun. I can see yours.

Probably sun_sun's distro has made some more options to proc filesystem. I don't have cpu entry either.

EDIT: Now I've read Osor's post.

sun_sun · 11-24-2007, 11:11 PM

Quote:

Originally Posted by Alien_Hominid

I was asking sun_sun. I can see yours.

Probably sun_sun's distro has made some more options to proc filesystem. I don't have cpu entry either.

EDIT: Now I've read Osor's post.

ok ok ...
you can skip the word ASAP...but then i needed it at the earliest..i thought to post it..by the time..i was trying to figure that out on my own..
nyways..
thanks