topic Re: I seee many process in sleep mode what does it mean in Operating System - HP-UX

I seee many process in sleep mode what does it mean

arun khatwani — Wed, 27 May 2009 14:10:04 GMT

mql 12253 matrix1 34.5 15 0.7 87.4mb 431.3mb STRMS
java 25718 matrix1 21.7 55 0.0 1.29gb 1.90gb SLEEP
java 12588 matrix1 19.4 78 0.3 1.21gb 1.56gb SLEEP
java 12576 matrix1 18.9 74 0.3 1.18gb 1.53gb SLEEP
java 3617 matrix1 17.3 33 0.0 902.2mb 1.50gb SLEEP
java 12584 matrix1 11.0 79 0.0 1.19gb 1.53gb SLEEP
java 1166 matrix1 7.4 32 0.0 1.24gb 1.86gb SLEEP
mql 6359 matrix1 3.6 15 0.0 91.3mb 434.5mb SLEEP

i see many processes in sleep mode wat does it mean.

Re: I seee many process in sleep mode what does it mean

Ganesan R — Wed, 27 May 2009 14:44:51 GMT

Hi,

if a process is sleeping mode, it means that the process is not being executed at that moment and waiting for some resources like i/o, cpu cycles, etc...

Re: I seee many process in sleep mode what does it mean

Steven E. Protter — Wed, 27 May 2009 14:45:26 GMT

Shalom,

You have an awful lot of processes with a large amount of memory in sleep mode.

Sleep mode means they are not active.

You probably have a java application and if the users are all idle, the processes are put to sleep by the OS because no work is being demanded.

So it could be quite innocent.

I think you might want to ask the application developers or provider why there is a need for so much memory to be in these processes.

SEP

Re: I seee many process in sleep mode what does it mean

James R. Ferguson — Wed, 27 May 2009 15:12:46 GMT

Hi:

As noted, a sleeping process is one that is waiting on an event.

In fact, you may want to impose a periodic sleep in simple loops to give other processes a chance to gain the processor.

while true do
[ -f myfile_available ] && break
sleep 1
done

...In the above loop, it would be "unkind" to others _not_ to sleep(). If you removed the sleep() you have written what is sometimes called a "buzz-loop".

Regards!

...JRF...

Re: I seee many process in sleep mode what does it mean

Laurent Menase — Wed, 27 May 2009 20:12:41 GMT

In fact SLEEPy process are not waiting for CPU ressources, but only IO, timeouts, synchronisation.
a process waiting for CPU is READY, waiting for the scheduler to RUN it.

So your process is waiting for IO like read()/select()/poll()/write() ... over sockets, diskIO, ttys
memory pagin/pageout like on memory map files
or timeout, like in a sleep(), sigwait(),
or synchronisations like mutexes ops, messagequeue operations, semaphores,

to understand on what they are waiting you can for instance use tusc.