Date: Thu, 10 Nov 2005 16:30:19 +0800
From: Wu Fengguang <wfg@mail.ustc.edu.cn>
To: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: linux-kernel@vger.kernel.org, Andrew Morton <akpm@osdl.org>
Subject: Re: [PATCH 04/16] radix-tree: look-aside cache
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On Thu, Nov 10, 2005 at 05:50:09PM +1100, Nick Piggin wrote:
> But it isn't *really* constant time lookups? I mean you'll
> always have the O(logn) lookup. Amortised I guess that
> becomes insignificant?

For sequential scan, I get 64*O(1) + 1*O(logn), that's pretty much gain.

> Briefly: is there a reason why you couldn't use gang lookups
> instead? (Sorry I haven't been able to read and understand your
> actual readahead code).

Because they have different semantics, one cannot replace the another.

> Profile numbers would be great for the cached / non-cached cases.

Ok, I'll do it, but at some time later. Currently I have several tasks that
need immediate handling, and that will take about a week. See you then :)

Regards,
Wu
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