Re: Hugetables question - Mailing list pgsql-hackers

From Radosław Smogura
Subject Re: Hugetables question
Date
Msg-id 201106191246.17577.rsmogura@softperience.eu
Whole thread Raw
In response to Re: Hugetables question  (Martijn van Oosterhout <kleptog@svana.org>)
List pgsql-hackers
Martijn van Oosterhout <kleptog@svana.org> Sunday 19 of June 2011 12:35:18
> On Sun, Jun 19, 2011 at 11:56:15AM +0200, Rados??aw Smogura wrote:
> > I want to implement hugepages for shared memory, to make it transparent I
> > want to do in this fashion:
> > 1. Reserve memory M of size s
> > 2. Try to allocate hugepage memory of as big size as possible (hs),
> > attach at M.
> > 3. Allocate normal shared memory of size hs - s, and attach it at M+hs.
> > This soulution should work for Linux and Windows, and make no difference
> > for usage of such shared memory in application.
> 
> At least in Linux they're trying to make hugepages transparent, so I'm
> wondering if this is going to make a difference for Linux in the long
> term.
> 
> As for your other problem, Perhaps you can put the shmem block first,
> before the hugemem block? Would require some pointer fiddling, but
> seems doable.
> 
> Habe a nice day,
> 
> > Patriotism is when love of your own people comes first; nationalism,
> > when hate for people other than your own comes first.
> > 
> >                                       - Charles de Gaulle
Yes shmem will be transparent in Linux, but in any case, currently is only for 
anonymous memory, and has some disadvantages over explicit hugepages.

Regards,
Radek


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