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From: Cyrill Gorcunov <gorcunov@gmail.com>
To: Ingo Molnar <mingo@elte.hu>
Subject: lockdep hashes
Date: Mon, 17 Dec 2007 16:01:07 +0300	[thread overview]
Message-ID: <20071217130107.GA7389@cvg.cvg> (raw)

Hi Ingo,

i'm quite sorry for annoying you with my stupid question but
i don't know whom to ask about lockdep hashes (you're the
author right?). Ingo look the code has

#define iterate_chain_key(key1, key2) \
	(((key1) << MAX_LOCKDEP_KEYS_BITS) ^ \
	((key1) >> (64-MAX_LOCKDEP_KEYS_BITS)) ^ \
	(key2))

but from where this function math is taken? How dod you find
it? (I read Knuth about hash functions and about prime numbers).
Or this is an experience who shows you the right hashing formula?
Could you point me in which direction i shoul to digg to understand this?

		Cyrill


                 reply	other threads:[~2007-12-17 13:06 UTC|newest]

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