# Why all server processess are running with a high priority?

## mitek

Hi,

Sorry, maybe this is an obvious thing, but I don't understand why 2 semi-identical boxes having different processes state. The box with kernel 31-r10 has all process in "S<" state, while 32-r7 has all processes in "S" state.  I've noticed it when Nagios reported that box2 (newer kernel) has 50 processes with STATE = RSZDT.

Is it good or bad? Which state they should be "S" or "S<" ?

Thank you!

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mitek@db1 ~ $ uname -a

Linux db1 2.6.31-gentoo-r10 #1 SMP Sat Apr 10 04:14:46 EST 2010 x86_64 Dual-Core AMD Opteron(tm) Processor 2212 HE AuthenticAMD GNU/Linux

mitek@db1 ~ $ ps aux

USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND

root         1  0.0  0.0   3836   632 ?        Ss   Apr25   0:05 init [3]

root         2  0.0  0.0      0     0 ?        S<   Apr25   0:00 [kthreadd]

root         3  0.0  0.0      0     0 ?        S<   Apr25   0:00 [migration/0]

root         4  0.0  0.0      0     0 ?        S<   Apr25   0:00 [ksoftirqd/0]

root         5  0.0  0.0      0     0 ?        S<   Apr25   0:00 [migration/1]

root         6  0.0  0.0      0     0 ?        S<   Apr25   0:00 [ksoftirqd/1]

root         7  0.0  0.0      0     0 ?        S<   Apr25   0:00 [migration/2]

root         8  0.0  0.0      0     0 ?        S<   Apr25   0:00 [ksoftirqd/2]

root         9  0.0  0.0      0     0 ?        S<   Apr25   0:00 [migration/3]

root        10  0.0  0.0      0     0 ?        S<   Apr25   0:00 [ksoftirqd/3]

root        11  0.0  0.0      0     0 ?        S<   Apr25   0:00 [events/0]

root        12  0.0  0.0      0     0 ?        S<   Apr25   0:38 [events/1]

root        13  0.0  0.0      0     0 ?        S<   Apr25   0:00 [events/2]

root        14  0.0  0.0      0     0 ?        S<   Apr25   0:00 [events/3]

root        15  0.0  0.0      0     0 ?        S<   Apr25   0:00 [cpuset]

root        16  0.0  0.0      0     0 ?        S<   Apr25   0:00 [khelper]

root        19  0.0  0.0      0     0 ?        S<   Apr25   0:00 [netns]

root        22  0.0  0.0      0     0 ?        S<   Apr25   0:00 [async/mgr]

root       195  0.0  0.0      0     0 ?        S<   Apr25   0:00 [kblockd/0]

root       196  0.0  0.0      0     0 ?        S<   Apr25   0:00 [kblockd/1]

root       197  0.0  0.0      0     0 ?        S<   Apr25   0:00 [kblockd/2]

root       198  0.0  0.0      0     0 ?        S<   Apr25   0:00 [kblockd/3]

root       201  0.0  0.0      0     0 ?        S<   Apr25   0:00 [kacpid]

root       202  0.0  0.0      0     0 ?        S<   Apr25   0:00 [kacpi_notify]

root       203  0.0  0.0      0     0 ?        S<   Apr25   0:00 [kacpi_hotplug]

root       308  0.0  0.0      0     0 ?        S<   Apr25   0:00 [ata/0]

root       309  0.0  0.0      0     0 ?        S<   Apr25   0:00 [ata/1]

root       310  0.0  0.0      0     0 ?        S<   Apr25   0:00 [ata/2]

root       311  0.0  0.0      0     0 ?        S<   Apr25   0:00 [ata/3]

root       312  0.0  0.0      0     0 ?        S<   Apr25   0:00 [ata_aux]

root       316  0.0  0.0      0     0 ?        S<   Apr25   0:00 [ksuspend_usbd]

root       320  0.0  0.0      0     0 ?        S<   Apr25   0:00 [khubd]

root       323  0.0  0.0      0     0 ?        S<   Apr25   0:00 [kseriod]

root       408  0.0  0.0      0     0 ?        S    Apr25   0:00 [pdflush]

root       409  0.0  0.0      0     0 ?        S    Apr25   2:44 [pdflush]

root       410  0.0  0.0      0     0 ?        S<   Apr25   0:00 [kswapd0]

root       411  0.0  0.0      0     0 ?        S<   Apr25   0:00 [kswapd1]

root       461  0.0  0.0      0     0 ?        S<   Apr25   0:00 [aio/0]

root       462  0.0  0.0      0     0 ?        S<   Apr25   0:00 [aio/1]

root       463  0.0  0.0      0     0 ?        S<   Apr25   0:00 [aio/2]

root       464  0.0  0.0      0     0 ?        S<   Apr25   0:00 [aio/3]

root       483  0.0  0.0      0     0 ?        S<   Apr25   0:00 [nfsiod]

root       488  0.0  0.0      0     0 ?        S<   Apr25   0:00 [crypto/0]

root       489  0.0  0.0      0     0 ?        S<   Apr25   0:00 [crypto/1]

root       490  0.0  0.0      0     0 ?        S<   Apr25   0:00 [crypto/2]

root       491  0.0  0.0      0     0 ?        S<   Apr25   0:00 [crypto/3]

root       709  0.0  0.0      0     0 ?        S<   Apr25   0:00 [bond0]

root       724  0.0  0.0      0     0 ?        S<   Apr25   0:00 [mpt_poll_0]

root       725  0.0  0.0      0     0 ?        S<   Apr25   0:00 [mpt/0]

root       726  0.0  0.0      0     0 ?        S<   Apr25   0:00 [scsi_eh_0]

root       804  0.0  0.0      0     0 ?        S<   Apr25   0:00 [kpsmoused]

root       811  0.0  0.0      0     0 ?        S<   Apr25   0:00 [kstriped]

root       815  0.0  0.0      0     0 ?        S<   Apr25   0:00 [kondemand/0]

root       816  0.0  0.0      0     0 ?        S<   Apr25   0:00 [kondemand/1]

root       817  0.0  0.0      0     0 ?        S<   Apr25   0:00 [kondemand/2]

root       818  0.0  0.0      0     0 ?        S<   Apr25   0:00 [kondemand/3]

root       846  0.0  0.0      0     0 ?        S<   Apr25   0:00 [usbhid_resumer]

root       859  0.0  0.0      0     0 ?        S<   Apr25   0:00 [rpciod/0]

root       860  0.0  0.0      0     0 ?        S<   Apr25   0:00 [rpciod/1]

root       861  0.0  0.0      0     0 ?        S<   Apr25   0:00 [rpciod/2]

root       862  0.0  0.0      0     0 ?        S<   Apr25   0:00 [rpciod/3]

root       870  0.0  0.0      0     0 ?        S<   Apr25   0:00 [reiserfs/0]

root       871  0.0  0.0      0     0 ?        S<   Apr25   0:00 [reiserfs/1]

root       872  0.0  0.0      0     0 ?        S<   Apr25   0:00 [reiserfs/2]

root       873  0.0  0.0      0     0 ?        S<   Apr25   0:00 [reiserfs/3]

=========================================================

mitek@db2 ~ $ uname -a

Linux db2 2.6.32-gentoo-r7 #2 SMP Sun May 9 12:25:29 EST 2010 x86_64 Dual-Core AMD Opteron(tm) Processor 2212 AuthenticAMD GNU/Linux

mitek@db2 ~ $ ps aux

USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND

root         1  0.0  0.0   3724   632 ?        Ss   12:40   0:00 init [3]

root         2  0.0  0.0      0     0 ?        S    12:40   0:00 [kthreadd]

root         3  0.0  0.0      0     0 ?        S    12:40   0:00 [migration/0]

root         4  0.0  0.0      0     0 ?        S    12:40   0:00 [ksoftirqd/0]

root         5  0.0  0.0      0     0 ?        S    12:40   0:00 [migration/1]

root         6  0.0  0.0      0     0 ?        S    12:40   0:00 [ksoftirqd/1]

root         7  0.0  0.0      0     0 ?        S    12:40   0:00 [events/0]

root         8  0.0  0.0      0     0 ?        S    12:40   0:00 [events/1]

root         9  0.0  0.0      0     0 ?        S    12:40   0:00 [cpuset]

root        10  0.0  0.0      0     0 ?        S    12:40   0:00 [khelper]

root        13  0.0  0.0      0     0 ?        S    12:40   0:00 [netns]

root        16  0.0  0.0      0     0 ?        S    12:40   0:00 [async/mgr]

root       185  0.0  0.0      0     0 ?        S    12:40   0:00 [sync_supers]

root       187  0.0  0.0      0     0 ?        S    12:40   0:00 [bdi-default]

root       189  0.0  0.0      0     0 ?        S    12:40   0:00 [kblockd/0]

root       190  0.0  0.0      0     0 ?        S    12:40   0:00 [kblockd/1]

root       193  0.0  0.0      0     0 ?        S    12:40   0:00 [kacpid]

root       194  0.0  0.0      0     0 ?        S    12:40   0:00 [kacpi_notify]

root       195  0.0  0.0      0     0 ?        S    12:40   0:00 [kacpi_hotplug]

root       308  0.0  0.0      0     0 ?        S    12:40   0:00 [ata/0]

root       309  0.0  0.0      0     0 ?        S    12:40   0:00 [ata/1]

root       310  0.0  0.0      0     0 ?        S    12:40   0:00 [ata_aux]

root       314  0.0  0.0      0     0 ?        S    12:40   0:00 [ksuspend_usbd]

root       318  0.0  0.0      0     0 ?        S    12:40   0:00 [khubd]

root       321  0.0  0.0      0     0 ?        S    12:40   0:00 [kseriod]

root       356  0.0  0.0      0     0 ?        S    12:40   0:00 [rpciod/0]

root       357  0.0  0.0      0     0 ?        S    12:40   0:00 [rpciod/1]

root       394  0.0  0.0      0     0 ?        S    12:40   0:00 [kswapd0]

root       446  0.0  0.0      0     0 ?        S    12:40   0:00 [aio/0]

root       447  0.0  0.0      0     0 ?        S    12:40   0:00 [aio/1]

root       466  0.0  0.0      0     0 ?        S    12:40   0:00 [nfsiod]

root       471  0.0  0.0      0     0 ?        S    12:40   0:00 [crypto/0]

root       472  0.0  0.0      0     0 ?        S    12:40   0:00 [crypto/1]

root       680  0.0  0.0      0     0 ?        S    12:40   0:00 [bond0]

root       690  0.0  0.0      0     0 ?        S    12:40   0:00 [mpt_poll_0]

root       691  0.0  0.0      0     0 ?        S    12:40   0:00 [mpt/0]

root       692  0.0  0.0      0     0 ?        S    12:40   0:00 [scsi_eh_0]

root       769  0.0  0.0      0     0 ?        S    12:40   0:00 [kpsmoused]

root       776  0.0  0.0      0     0 ?        S    12:40   0:00 [kstriped]

root       780  0.0  0.0      0     0 ?        S    12:40   0:00 [kondemand/0]

root       781  0.0  0.0      0     0 ?        S    12:40   0:00 [kondemand/1]

root       810  0.0  0.0      0     0 ?        S    12:40   0:00 [usbhid_resumer]

root       826  0.0  0.0      0     0 ?        S    12:40   0:00 [reiserfs/0]

root       827  0.0  0.0      0     0 ?        S    12:40   0:00 [reiserfs/1]

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## mitek

anyone?

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## krinn

unsure, just guessing there.

both are sleeping but the < is higher priority, i have plenty on my server, and few on my desktop. I think it's the low latency profile vs server profile, low latency scheduling should gave a fairer priority to everyone, so all applications should respond better but won't get a better usage of cpu ressource while the server one should gave a fewer response while applications get more cpu power.

maybe you use different scheduling on your two kernel.

or it might just be difference from kernel version made by dev choices.

but just a guess.

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## mitek

Thank you, krinn!

I think you are right, I'll start digging in that direction.

I briefly checked, both servers were in Desktop Preemption Model, but I'll check other parameters.

Cheers!

 *krinn wrote:*   

> unsure, just guessing there.
> 
> both are sleeping but the < is higher priority, i have plenty on my server, and few on my desktop. I think it's the low latency profile vs server profile, low latency scheduling should gave a fairer priority to everyone, so all applications should respond better but won't get a better usage of cpu ressource while the server one should gave a fewer response while applications get more cpu power.
> 
> maybe you use different scheduling on your two kernel.
> ...

 

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## widremann

 *krinn wrote:*   

> unsure, just guessing there.
> 
> both are sleeping but the < is higher priority, i have plenty on my server, and few on my desktop. I think it's the low latency profile vs server profile, low latency scheduling should gave a fairer priority to everyone, so all applications should respond better but won't get a better usage of cpu ressource while the server one should gave a fewer response while applications get more cpu power.
> 
> maybe you use different scheduling on your two kernel.
> ...

 

That's can't be it, because the '<' indicates the explicit priority set to the process via, e.g., nice and renice.  It doesn't have anything to do with dynamic priority and whatever little tricks the kernel might use to do a good job scheduling.

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## mitek

Hi wirdemann,

I have not found any differences in kernel configs, what is doing this?

Thanks!

 *widremann wrote:*   

> 
> 
> That's can't be it, because the '<' indicates the explicit priority set to the process via, e.g., nice and renice.  It doesn't have anything to do with dynamic priority and whatever little tricks the kernel might use to do a good job scheduling.

 

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