Re: [Lhms-devel] [PATCH 0/7] Fragmentation Avoidance V19

Nick Piggin
2005-11-04T01:22:18Z

Linus Torvalds wrote:
>
> On Fri, 4 Nov 2005, Nick Piggin wrote:
>
>>Looks like ppc64 is getting 64K page support, at which point higher
>>order allocations (eg. for stacks) basically disappear don't they?
>
>
> Yes and no, HOWEVER, nobody sane will ever use 64kB pages on a
> general-purpose machine.
>
> 64kB pages are _only_ usable for databases, nothing else.
>
> Why? Do the math. Try to cache the whole kernel source tree in 4kB pages
> vs 64kB pages. See how the memory usage goes up by a factor of _four_.
>

Yeah that's true. But Martin's worried about future machines
with massive memories - so maybe it is safe to assume those will
be using big pages, I don't know.

Maybe the solution is to bloat the kernel sources enough to make
64KB pages worthwhile?

--
SUSE Labs, Novell Inc.

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