APLawrence.com -  Resources for Unix and Linux Systems, Bloggers and the self-employed

linux shmmax

© December 2004 (various authors)
From: Graham Brereton <exit_music_ok@yahoo.co.uk>
Newsgroups: comp.os.linux.misc
Subject: Re: How to modify the value of SHMMAX?
Date: Sat, 16 Sep 2000 01:19:48 +0100
Message-ID: <39C2BCA4.BE9EB5AC@yahoo.co.uk> 
References: <8psmgs$2789$1@news.cz.js.cn> 

David wrote:
> How to do it?
> Thanks

echo VAL > /proc/sys/kernel/shmmax (or something similar)

sysctl -w sys.kernel.shmmax=VAL (or something similar)

Don't get my sympathy hanging out the 15th floor...

And also you can set this with (for example)

echo "kernel.shmmax=2147483648" >> /etc/sysctl.conf

Got something to add? Send me email.

(OLDER)    <- More Stuff -> (NEWER)    (NEWEST)   

Printer Friendly Version

-> linux shmmax ––>Re: How to modify the value ofSHMMAX?


Inexpensive and informative Apple related e-books:

Take Control of Apple Mail, Third Edition

Take Control of iCloud, Fifth Edition

iOS 8: A Take Control Crash Course

Take Control of Numbers

Take Control of Upgrading to El Capitan

Wed Mar 30 12:04:08 2005: 248   anonymous

what is shared memory segment of a shmmax

Wed Mar 30 12:29:46 2005: 250   TonyLawrence

Not sure what you mean - SHMMAX sets the maximumum size of a shared memory segment - it's a kernel variable. Are you asking what it would like like in proc?
You can ses them in /proc/sysvipc/shm or use ipcs.. or do you mean where it would be in the map of a process? You can see that in /proc/(pid)/maps - and there's not a lot more I can tell you; I'm no kernel expert..

I can show you a shared segment as it looks on my system. Here's /proc/sysvipc/shm
 key      shmid perms       size  cpid  lpid nattch   uid   gid  cuid  cgid      atime      dtime      ctime
   0    1048576  1600     524288  7124  7124      1     0     0     0     0 1112173371          0 1112173371

and here's the line from /proc/7124/maps:
b6668000-b66e8000 rwxs 00000000 00:04 1048576    /SYSV00000000 (deleted)


Printer Friendly Version

Have you tried Searching this site?

This is a Unix/Linux resource website. It contains technical articles about Unix, Linux and general computing related subjects, opinion, news, help files, how-to's, tutorials and more.

Contact us

Printer Friendly Version

If Linux can skate by the patent and copyright issues, its growth in the corporate world will continue no matter what business dislikes about the GPL. (Tony Lawrence)

Linux posts

Troubleshooting posts

This post tagged:



Unix/Linux Consultants

Skills Tests

Unix/Linux Book Reviews

My Unix/Linux Troubleshooting Book

This site runs on Linode