On Mon, 20 Mar 2000, Helge Hafting wrote:
>You don't understand overcommitting. The problem is that some
>techniques, particularly fork() tries to allocate much more memory than
>it will ever need. So preventing fork() when there isn't memory to back
>it will severely restrict the number of processes you may run, or force
>you to install many gigabytes of swap that won't ever be used. This
>would effectively make linux unusable for some tasks on small machines.
>(I.e. hobbyist machines and those money-saving old machines corporations
>use with linux) You can run your machine that way though, take a look
>at /proc/sys/vm/overcommit_memory
But "echo 0 > /proc/sys/vm/overcommit_memory" does not prevent memory
overcommit in a global sense, it just prevents any one program from using
more VM than is currently free. Since memory is still not allocated until
pages are touched, you can still be heavily overcommitted.
Dave
David Whysong dwhysong@physics.ucsb.edu
Astrophysics graduate student University of California, Santa Barbara
My public PGP keys are on my web page - http://www.physics.ucsb.edu/~dwhysong
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This archive was generated by hypermail 2b29 : Thu Mar 23 2000 - 21:00:29 EST