Re: larger default page sizes...

[Paul Mackerras <paulus@samba.org>]

David Miller writes:

> From: Paul Mackerras <paulus@samba.org>
> Date: Tue, 25 Mar 2008 14:29:55 +1100
> 
> > The performance advantage of using hardware 64k pages is pretty
> > compelling, on a wide range of programs, and particularly on HPC apps.
> 
> Please read the rest of my responses in this thread, you
> can have your HPC cake and eat it too.

It's not just HPC, as I pointed out, it's pretty much everything,
including kernel compiles.  And "use hugepages" is a pretty inadequate
answer given the restrictions of hugepages and the difficulty of using
them.  How do I get gcc to use hugepages, for instance?  Using 64k
pages gives us a performance boost for almost everything without the
user having to do anything.

If the hugepage stuff was in a state where it enabled large pages to
be used for mapping an existing program, where possible, without any
changes to the executable, then I would agree with you.  But it isn't,
it's a long way from that, and (as I understand it) Linus has in the
past opposed the suggestion that we should move in that direction.

Paul.