Lack of the knowlege about semapore policy

[KCS_1]

Hi,


I tried to change a couple of kernel parameters about semapore that called semmni,semmns to be maximum size ( 65535 ) by SAM. However, there some messages were involved. so want to know why.

Here are current value of Semapore by kmtune

-----------------------------------------
sema 1 - 1
semaem 32767 - 16384
semmap 32767 - (SEMMNI+2)
semmni 32765 - 64
semmns 32767 - 128
semmnu 30 - 30
semmsl 2048 Y 2048
semume 10 - 10
semvmx 65535 - 32767

[RAC_1]

There is no need to set semmni and semmns to 65535. What prompted you to set it so high?

Refer following link to understand what they stand for.
http://docs.hp.com/hpux/onlinedocs/939/KCParms/KCparams.OverviewAll.html

Also what is the error message you get?

[Jakes Louw]

I must admit, I'm also struggling to understand what you need. Some of the params are linked, so you would have probably have caused SAM to tell you to first increase one before the other.

[KCS_1]

yes, I was just curious why these parameter sets are fixed as maximum value.

semmni 32765 <---
isn't not a maximum value according to semvmx description

semmns 32767 <--- Neither

Why I can't extend them to 65535?


I respect to hear more advanced explaination.


Thanks

[Chris Wilshaw]

Presumably, the error you get is

The value specified for tunable parameter "semmns", "65535",
evaluates to "65535" which is more than the maximum allowed value of "32767".

These are limits set on the kernel to prevent over-use of resources, which would (potentially) cripple your system. As far as I know, there is no supported way of increasing these values.