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To: Julian Elischer <julian@freebsd.org>
Subject: Re: PoC: passive serialization
In-reply-to: <53A7A2D6.30905@freebsd.org>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
References: <539FEBC1.5030501@FreeBSD.org>
 <20140621231853.394A914A2D0@mail.netbsd.org> <53A7A2D6.30905@freebsd.org>
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Date: Mon, 23 Jun 2014 06:08:46 +0000
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In message <53A7A2D6.30905@freebsd.org>, Julian Elischer writes:
>On 6/22/14, 7:18 AM, Mindaugas Rasiukevicius wrote:
>>
>> Just a note on passive serialization in NetBSD: there is a lot of space for
>> optimisations, simplifications or improvements to that code, but it was a
>> deliberate choice to avoid them.  The goal was to carefully implement the
>> logic described in the expired patent (or at least attempt to be as close as
>> our interpretation skills allow us to be).  Any deviation from that logic
>> increases the risk of falling under some other technique, primarily RCU,
>> covered by other patent.
>>
>hopefully the recent ruling on software patents may make the whole 
>thing moot given enough impetus.

Probably not in this case.

This bite from page 3 seems like the gate through which RCU and similar
patents will go:

	"They do not, for example, purport to improve the functioning
	 of the computer itself"

But read for yourself:

	http://www.supremecourt.gov/opinions/13pdf/13-298_7lh8.pdf

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.