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From: "Michael K. Edwards" <medwards.linux@gmail.com>
To: "Zach Brown" <zab@zabbo.net>
Cc: "Nick Piggin" <npiggin@suse.de>,
	"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
	"Davide Libenzi" <davidel@xmailserver.org>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: Re: [rfc][patch] dynamic resizing dentry hash using RCU
Date: Fri, 23 Feb 2007 17:31:30 -0800	[thread overview]
Message-ID: <f2b55d220702231731l10d36e66h67dd185feb52e8a5@mail.gmail.com> (raw)
In-Reply-To: <5FD7605C-E132-4893-86FA-F76DDFB16389@zabbo.net>

On 2/23/07, Zach Brown <zab@zabbo.net> wrote:
> I'd love to see a generic implementation of RCU hashing that
> subsystems can then take advantage of.  It's long been on the fun
> side of my todo list.  The side I never get to :/.

There's an active thread on netdev about implementing an RCU hash.
I'd suggest a 2-left (or possibly even k-left) hash for statistical
reasons discussed briefly there, and in greater depth in a paper by
Michael Mitzenmacher at
www.eecs.harvard.edu/~michaelm/NEWWORK/postscripts/iproute.ps.
Despite his paper's emphasis on hardware parallelism, there's a bigger
win associated with Poisson statistics and decreasing occupation
fraction (and therefore collision probability) in successive hashes.

Cheers,
- Michael

  parent reply	other threads:[~2007-02-24  1:31 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-02-23 15:37 Nick Piggin
2007-02-23 16:31 ` Eric Dumazet
2007-02-24  1:08   ` Nick Piggin
2007-02-23 17:25 ` Zach Brown
2007-02-24  1:26   ` Nick Piggin
2007-02-24  2:07     ` Nick Piggin
2007-02-24  1:31   ` Michael K. Edwards [this message]
2007-02-24  1:52     ` Nick Piggin
2007-02-24  4:07 ` KAMEZAWA Hiroyuki
2007-02-24  5:15   ` Nick Piggin
2007-02-24  4:24 ` William Lee Irwin III
2007-02-24  5:09   ` Nick Piggin
2007-02-24 22:56     ` William Lee Irwin III
2007-02-25  0:56       ` David Miller
2007-02-25  2:15         ` William Lee Irwin III
2007-02-25  6:21 ` Paul E. McKenney
2007-03-05  4:11 ` David Miller
2007-03-05  4:27   ` Nick Piggin
2007-03-05  4:38     ` David Miller
2007-03-05  4:42     ` Nick Piggin

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