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From: Dave Taht <dave@taht.net>
To: Jonathan Morton <chromatix99@gmail.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>,
	codel@lists.bufferbloat.net, bloat <bloat@lists.bufferbloat.net>
Subject: Re: [Bloat] [Codel]   found another good use for a queue today, possibly
Date: Wed, 28 Nov 2018 20:37:52 -0800	[thread overview]
Message-ID: <87ftvkzefz.fsf@taht.net> (raw)
In-Reply-To: <5CA2D845-508D-421C-AF38-E2B5AE0E54B2@gmail.com> (Jonathan Morton's message of "Tue, 27 Nov 2018 06:17:19 +0200")

Jonathan Morton <chromatix99@gmail.com> writes:

>>> "polylog(n)-wise Independent Hash Function". OK, my google-foo fails
>>> me: The authors use sha1, would something lighter weight suit?
>
>> The current favorite in DPDK land seems to be Cuckoo hashing.
>> It has better cache behavior than typical chaining.
>
> That paper describes an improved variant of cuckoo hashing, using a
> queue to help resolve collisions with better time complexity.  The
> proof relies on (among other things) a particular grade of hash
> function being used.  SHA1 is described as being suitable since it
> offers cryptographic-level performance… We actually need two hashes
> with independent behaviour on the same input, one for each table.
>
> If we were to assume table sizes up to 64K, using both halves of a
> good 32-bit hash might be suitable.  It may be that plain old Jenkins
> hash would work in that context.  Supplement that with a 64-entry
> queue with linear search (in software) or constant-time CAM search (in
> hardware).

I was aiming for 2million routes.

I gave up trying to wade through it and pinged the authors.

fiddling with blake at the moment

>
>  - Jonathan Morton
>
> _______________________________________________
> Codel mailing list
> Codel@lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/codel

  reply	other threads:[~2018-11-29  4:38 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-27  2:17 [Bloat] " Dave Taht
2018-11-27  4:08 ` [Bloat] [Codel] " Stephen Hemminger
2018-11-27  4:17   ` Jonathan Morton
2018-11-29  4:37     ` Dave Taht [this message]
2018-11-29 17:17 ` [Bloat] " Dave Taht

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