Re: Hugepages - benefits / drawbacks

ipcs probably won't show anything interesting. Can you check truss output when you do a big sort (select count(*) from dba_source order by 1)? Filter on calls such as brk, mmap (get args of this). Also pmap -x | grep shmid. See if the mapped size increases when you do big sorting. And, pmap -s <your shadow process> to see which page size segment increases its size.

Yong Huang

• On Tue, 10/7/08, Roman Podshivalov <roman.podshivalov_at_gmail.com> wrote:

> From: Roman Podshivalov <roman.podshivalov_at_gmail.com>
> Subject: Re: Hugepages - benefits / drawbacks
> To: yong321_at_yahoo.com
> Cc: "Christo Kutrovsky" <kutrovsky.oracle_at_gmail.com>, oracle-l_at_freelists.org, krishmanoh_at_gmail.com
> Date: Tuesday, October 7, 2008, 1:59 PM
>
> Yep that parameter caught my attention too. I just did a
> quick test and
> started database with this parameter set to true and false.
> No difference in
> ipcs -ma output was found....Could that be related to MTS
> configuration ?
>
> --romas
>
> On Tue, Oct 7, 2008 at 2:55 PM, Yong Huang
> <yong321_at_yahoo.com> wrote:
>
> > > On Tue, Oct 7, 2008 at 1:26 PM, Yong Huang
> > > <yong321_at_yahoo.com> wrote:
> > > > Hi Krishna,
> > > >
> > > >> on Solaris PGA uses ISM
> > > >
> > > > Wouldn't that cause PGA to be shared?
> >
> > Tanel Poder's presentation "Memory Management
> and Latching Improvements in
> > Oracle9i and 10g" mentions the parameter
> _use_ism_for_pga. It didn't
> > register in my mind when I read it some time ago. I
> don't have access to
> > Oracle on Solaris right now. Why does Oracle do this?
> It would be
> > interesting to see the effect.
> >
> > Yong Huang
      

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