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From: Sean Young <sean@mess.org>
To: linux-kernel@vger.kernel.org
Cc: Joern Engel <joern@logfs.org>
Subject: Re: [RFC] B+Tree library
Date: Fri, 31 Oct 2008 20:17:45 +0000	[thread overview]
Message-ID: <20081031201745.GA93714@atlantis.8hz.com> (raw)
In-Reply-To: <20081026124643.GA1328@logfs.org>

On Sun, Oct 26, 2008 at 01:46:44PM +0100, Joern Engel wrote:
> General advantages of btrees are memory density and efficient use of
> cachelines.  Hashtables are either too small and degrade into linked
> list performance, or they are too large and waste memory.  With changing
> workloads, both may be true on the same system.  Rbtrees have a bad
> fanout of less than 2 (they are not actually balanced binary trees),
> hence reading a fairly large number of cachelines to each lookup.

Which reminds me:

find_vma() uses rbtrees. Now I assume find_vma() is called far more than
mmap() and friends. Since avltree are balanced (unlike rbtrees) lookups
will be faster at the expense of extra rotations during updates.

Would patches for avltrees be accepted?

Thanks
Sean

  parent reply	other threads:[~2008-10-31 20:45 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-26 12:46 [RFC] B+Tree library Jörn Engel
2008-10-28  1:25 ` Dave Chinner
2008-10-30 17:43 ` Pavel Machek
2008-10-30 17:58   ` Jörn Engel
2008-10-30 19:14     ` Pavel Machek
2008-10-30 20:20       ` Jörn Engel
2008-10-31  6:38     ` Christian Borntraeger
2008-10-31  7:35       ` Jörn Engel
2008-10-31  9:16         ` Geert Uytterhoeven
2008-10-31  9:20           ` Jörn Engel
2008-10-31 10:35 ` Johannes Berg
2008-10-31 11:26   ` Jörn Engel
2008-10-31 11:32     ` Johannes Berg
2008-10-31 12:54       ` Jörn Engel
2008-10-31 13:07         ` Johannes Berg
2008-10-31 13:15           ` Jörn Engel
2008-11-01 15:59         ` [RFC] B+Tree library V2 Jörn Engel
2008-11-05 19:57           ` Johannes Berg
2008-11-05 20:06             ` Jörn Engel
2008-11-05 20:12               ` Johannes Berg
2008-11-05 20:21                 ` Jörn Engel
2008-11-05 20:25                   ` Johannes Berg
2008-11-07  7:52                     ` Jörn Engel
2009-01-08  0:57           ` Johannes Berg
2009-01-08 16:24             ` Jörn Engel
2009-01-08 16:34               ` Johannes Berg
2009-01-08 19:40                 ` Jörn Engel
2009-01-08 16:50               ` Johannes Berg
2009-01-08 19:46                 ` Jörn Engel
2009-01-08 17:10               ` Johannes Berg
2009-01-08 20:02                 ` Jörn Engel
2009-01-08 20:18                   ` Johannes Berg
2009-01-08 21:09                     ` Jörn Engel
2008-10-31 13:16 ` [RFC] B+Tree library Johannes Berg
2008-10-31 13:29   ` Jörn Engel
2008-10-31 13:45   ` Bert Wesarg
2008-10-31 15:18   ` Tim Gardner
2008-10-31 15:35     ` Jörn Engel
2008-10-31 20:17 ` Sean Young [this message]
2008-10-31 23:36   ` Jörn Engel
2008-11-01 10:17     ` Sean Young

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