Re: Changing SEMVMX to a tunable parameter

[Manfred Spraul <manfred@colorfullife.com>]

Arvind Kandhare wrote:

>1. Most of the IPC parameters (e.g. msgmni, msgmax, 
>msgmnb , shmmni, shmmax) are tunables. 
>
>(Please refer : 
>http://web.gnu.walfield.org/mail-archive/linux-kernel-digest/1999-November/0020.html)
>
>Was there any specific reason why semvmx was not made a tunable with the 
>above set??  
>  
>
Because I didn't see the need for making it tunable.

>2. By having semvmx as tunable, administrator gets more flexibility 
>in controlling the resource usage on the system:
>        a. By increasing this, it is possible to allow more     
>        processes to use the system resources controlled by a
>        semaphore concurrently.
>  
>
Changing semvmx has no effect on the resource usage: An integer occupies 
4 bytes, a short 2 bytes, independant of it's value.

>Because of problems with dynamic tuning (ref first mail on the subject), 
>static tuning (boot time) is proposed.
>
>Please let us know your comments.
>  
>
Review everything for signed/unsigned problems, then post your findings 
and a patch that increases the limit to 64k. The whole patch will be 
shorter than the "confidential" disclaimer at the end of your mails.

--
    Manfred