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From: "Stephen C. Tweedie" <sct@redhat.com>
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Date: Fri, 12 Nov 1999 17:33:35 +0000 (GMT)
To: Ingo Molnar <mingo@chiara.csoma.elte.hu>
Cc: Linus Torvalds <torvalds@transmeta.com>, linux-kernel@vger.rutgers.edu, "Stephen C. Tweedie" <sct@redhat.com>, Alan Cox <number6@the-village.bc.nu>
Subject: Re: [patch] zoned-2.3.27-E0
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Hi,

On Fri, 12 Nov 1999 15:02:31 +0100 (CET), Ingo Molnar
<mingo@chiara.csoma.elte.hu> said:

> Stephen noticed that 2.3.27 doesnt boot on <=16MB boxes due to the zoned
> allocator changes. The attached patch should fix this. Unfortunately i
> found no way to prevent introducing the runtime 'nr_zones' variable.

A quick special-case check on zones known to be empty would allow you to
maintain performance even if you have zones which will never have any
pages in them on a given machine.

You need this anyway --- Alan pointed out that it is a significant hit
on benchmarks if, during normal running, one zone fills up and you start
falling back routinely to a lower zone.

--Stephen

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