Clearing memory?

Huntsinger, Reid reid_huntsinger at merck.com
Tue Mar 26 10:52:31 EST 2002


To add to the previous response, the early 2.4 kernels didn't give up memory
used as cache easily enough. If you ran a process which allocated and used
lots of memory, then ran it again upon termination, you would see it swap
heavily the second time, and take much longer. This doesn't happen with
later kernels as far as I've seen. 

Red Hat 7.1 uses a very early kernel; you should certainly get a newer one.

Reid Huntsinger 



Date: Mon, 25 Mar 2002 20:02:25 -0500 (EST)
From: Qiang Cui <qiang at tammy.harvard.edu>
To: beowulf at beowulf.org
Subject: Clearing memory?

Dear all,

	We are using an Athlon based beowulf cluster to perform CHARMM
type of calculations (OS: Redhat 7.1). One issue that we noticed is that
the memory available to use seems to be decreasing all the time: our
machines come with 1GB of memory, but "top" tells us that the available
memory is only on the order of several hundred MBs even without any
serious calculations - it looks like that some blocks of memory were not
fully released after previous calculations. This problem forces us to
reboot the machine from time to time for large-memory calculations. 

	Any suggestions on how to cope with this problem? Thanks!

___________________________________________________________________________

Qiang Cui                   
Dept. of Chem.                   _ __..-;''`--/'/ /.',-`-.
Harvard Univ.                  (`/' ` |  \ \ \\ / / / / .-'/`,_
12 Oxford St.,                /'`\ \   |  \ | \| // // / -.,/_,'-,
Cambridge, MA 02138          /<7' ;  \ \  | ; ||/ /| | \/    |`-/,/-.,_,/')
(617)-495-8997              /  _.-, `,-\,__|  _-| / \ \/|_/  |    '-/.;.\'
(617)-495-1775              `-`  f/ ;      / __/ \__ `/ |__/ |
Fax: (617)-496-3204              `-'      |  -| =|\_  \  |-' |
     (617)-496-4793                    __/   /_..-' `  ),'  //
                                      ((__.-'((___..-'' \__.'

http://yuri.harvard.edu/~qiang/wisc/research.html
http://yuri.harvard.edu/~qiang

32 Whites Ave. #4408          
Watertown, MA 02472
(617)-926-6027

------------------------------------------------------------------------------
Notice: This e-mail message, together with any attachments, contains information of Merck & Co., Inc. (Whitehouse Station, New Jersey, USA) that may be confidential, proprietary copyrighted and/or legally privileged, and is intended solely for the use of the individual or entity named on this message. If you are not the intended recipient, and have received this message in error, please immediately return this by e-mail and then delete it.

==============================================================================

_______________________________________________
Beowulf mailing list, Beowulf at beowulf.org
To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf



More information about the Beowulf mailing list