RE: Large SGA in Solaris
Date: Fri, 8 May 2009 15:44:00 +0300
Message-ID: <41DE6ACE4DDE436A9D31BCAE98F84932_at_porgand>
That's what I said in my post too ;-)
When you use DISM it means you are using pageable memory for SGA. Non-dynamic ISM will use non-pageable memory pages, which are locked into physical RAM. When a page is not pageable, it can't be paged out, thus it doesn't need swap space to back that allocation.
And yes, I do have a blog entry describing this ;-)
http://blog.tanelpoder.com/2007/08/28/operating-systems-are-lazy-allocating-
memory/
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Regards,
Tanel Poder
http://blog.tanelpoder.com <http://blog.tanelpoder.com/>
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org]
On Behalf Of Charles Schultz
Sent: 08 May 2009 15:16
To: exriscer_at_gmail.com
Cc: oracle-l-freelists
Subject: Re: Large SGA in Solaris
Just to add to that, the swap space for DISM has to be backed by disk. We found this through trial and testing. =) Just throwing up some ramfs is not good enough. I am not exactly sure why this is, as I have not yet fully understood the whitepapers that Sun and Oracle both provided.
On Fri, May 8, 2009 at 06:37, Tanel Poder <tanel_at_poderc.com> wrote:
Oracle uses large pages (ISM) by default on solaris, so you'll get 4MB or larger pages on SPARC. ISM/DISM pagetables are sharable so you shouldn't have any kernel memory overhead problems.
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Received on Fri May 08 2009 - 07:44:00 CDT