linux-kernel - Re: larger default page sizes...

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <18408.59112.945786.488350@cargo.ozlabs.ibm.com>
Date:	Tue, 25 Mar 2008 22:50:00 +1100
From:	Paul Mackerras <paulus@...ba.org>
To:	David Miller <davem@...emloft.net>
Cc:	clameter@....com, linux-mm@...ck.org, linux-kernel@...r.kernel.org,
	linux-ia64@...r.kernel.org, torvalds@...ux-foundation.org
Subject: Re: larger default page sizes...

David Miller writes:

> From: Paul Mackerras <paulus@...ba.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.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/