From owner-freebsd-arch@FreeBSD.ORG Sun Jun 22 12:35:03 2014 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 899988BC; Sun, 22 Jun 2014 12:35:03 +0000 (UTC) Received: from mail-we0-x22c.google.com (mail-we0-x22c.google.com [IPv6:2a00:1450:400c:c03::22c]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id F25622269; Sun, 22 Jun 2014 12:35:02 +0000 (UTC) Received: by mail-we0-f172.google.com with SMTP id u57so5709095wes.17 for ; Sun, 22 Jun 2014 05:35:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=IX/jmEMpxXZUhkgH87iebJV6jPgfS5yiyDtpOD2yrpM=; b=wgZMldyNHWqeinF3/BtpJkBl0Qn6OemMsGHuvELBS3QXD3C/38O7Dxn6Rc7YFHvWN2 UDHtIPwlvFmfGuY+orhE6SRekR0EQe95lN4Es6Tw2HOJsxsxjCjEPVw5UUkVBqafOz2+ 5FVlW9XFgxuiV+BwPnmwEAZSBNl/uheNv38hR/zgwZduh8zjRPaACTN8fB83Q8+bQvPc oS7wE8Ev3OigoUnkO5nA/oDbLp/xiCMgttkiEqSfHIAPIrVoiuwua92cIlJUaGMklr/f i/UU1uHKFvO/wcCvNXW4+2zgZDqY7A1YZYVrjoOdO7FNMeibxmDZm6gsjqW11EDvtxjf 0+xQ== X-Received: by 10.194.77.177 with SMTP id t17mr18769661wjw.55.1403440500871; Sun, 22 Jun 2014 05:35:00 -0700 (PDT) Received: from dft-labs.eu (n1x0n-1-pt.tunnel.tserv5.lon1.ipv6.he.net. [2001:470:1f08:1f7::2]) by mx.google.com with ESMTPSA id ww4sm1324556wjc.4.2014.06.22.05.34.59 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Sun, 22 Jun 2014 05:35:00 -0700 (PDT) Date: Sun, 22 Jun 2014 14:34:57 +0200 From: Mateusz Guzik To: Mindaugas Rasiukevicius Subject: Re: PoC: passive serialization Message-ID: <20140622123457.GA20525@dft-labs.eu> References: <539FEBC1.5030501@FreeBSD.org> <20140621231853.394A914A2D0@mail.netbsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20140621231853.394A914A2D0@mail.netbsd.org> User-Agent: Mutt/1.5.21 (2010-09-15) Cc: Andrey Zonov , freebsd-arch@FreeBSD.org X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 22 Jun 2014 12:35:03 -0000 On Sun, Jun 22, 2014 at 12:18:52AM +0100, 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. > Cursory look suggests passive serialization got very limited use in NetBSD, I was also unable to find any benchmarks. I do understand and appreciate your cautious approach, but it also limits the potential. Do you have any materials which would show gains of using the concept as implemented in your code? Right now it is unclear if the implementation limited to this patent can yield benefits which would justify added complexity. Thanks, -- Mateusz Guzik