RE: Large SGA in Solaris
- From: "Tanel Poder" <tanel@xxxxxxxxxx>
- To: <sacrophyte@xxxxxxxxx>, <exriscer@xxxxxxxxx>
- Date: Fri, 8 May 2009 15:44:00 +0300
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/
--
Regards,
Tanel Poder
http://blog.tanelpoder.com <http://blog.tanelpoder.com/>
_____
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of Charles Schultz
Sent: 08 May 2009 15:16
To: exriscer@xxxxxxxxx
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@xxxxxxxxxx> 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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