lkml.org 
[lkml]   [2000]   [Mar]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Overcommitable memory??

[CC list trimmed again, I doubt Stephen Tweedie or Rik van Riel are
interested in this discussion.]

On Tue, 21 Mar 2000, James Sutherland wrote:

>>Preventing system OOM using resource limits is equivalent to disabling
>>overcommit. You have to restrict each of N users to 1/N of the total
>>system memory.
>
>No. That is NOT overcommit. Overcommit, in this context, is when a
>process calls malloc() and is given unpopulated address space, which
>will be populated on use.

In the quota case, in order to prevent a system-wide OOM you must give
each of N users an average of 1/N of the total system memory (ignoring
kernel overhead). The side effect is that overcommittment is now
impossible, because the system can only be overcommitted if a user has
exceeded their quota, which is not allowed...

Unless you don't count COW pages against a user's quota?

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
DSS PGP Key 0x903F5BD6 : FE78 91FE 4508 106F 7C88 1706 B792 6995 903F 5BD6
D-H PGP key 0x5DAB0F91 : BC33 0F36 FCCD E72C 441F 663A 72ED 7FB7 5DAB 0F91



-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:57    [W:0.150 / U:0.100 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site