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Date: Thu, 26 Apr 2012 12:00:31 +0200
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Subject: Re: [PATCH 1/3] Range tree implementation
From: Dmitry Adamushko <dmitry.adamushko@gmail.com>
To: John Stultz <john.stultz@linaro.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Android Kernel Team <kernel-team@android.com>,
        Robert Love <rlove@google.com>, Mel Gorman <mel@csn.ul.ie>,
        Hugh Dickins <hughd@google.com>, Dave Hansen <dave@linux.vnet.ibm.com>,
        Rik van Riel <riel@redhat.com>, Dave Chinner <david@fromorbit.com>,
        Neil Brown <neilb@suse.de>, Andrea Righi <andrea@betterlinux.com>,
        "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
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>> [ ... ]
>>
>> Almost everything is common rb_tree-handling code that can be found in
>> any place where rb-trees are used (hard-coded for flexibility,
>> performance or whatever other reasons). So my feeling is that it
>> should not be different here.
>>
> Sorry, not sure I quite understand what you're suggesting. Are you saying it
> doesn't make sense to have a generic range tree implementation, since really
> its just a small shim over the rbtree code?  So instead range-tree users
> should just implment them themselves?

Exactly. It's not much different from other rbtree
search-insert-delete implementations out there.

What are the generic use cases that we want to support with this interface?

Is the current notion of the 'overlapping range' as taken by
range_tree_in_range() common enough? What if another use-case requires
_only_ the ranges that are strictly inside the [ start, end ] range?
In this case, we might be better off sticking to the same
'implement-your-own-search' approach taken by the generic rbtree
interface.

-- Dmitry