Re: Overcommitable memory??

From: Rask Ingemann Lambertsen (
Date: Wed Mar 15 2000 - 13:22:52 EST

Den 15-Mar-00 11:49:45 skrev James Sutherland fĝlgende om "Re: Overcommitable memory??":
> On Wed, 15 Mar 2000, David Whysong wrote:

>> The only possibilities are to (a) enforce hard memory limits with no
>> overcommit, thereby wasting large amounts of swap space that will never
>> get used while not really solving the problem,

> As well as *destroying* performance (you'd effectively eliminate COW
> capability on fork - if your 500Mb simulation wants to fork a 100k mailer
> process to send you an update, the kernel has to allocate and copy 500Mb
> of RAM/swap first, then discard it all again.)

   Not at all. COW is a performance optimisation which does not depend on
overcommitment of memory in any way. Why would you want to turn it off?


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