From owner-freebsd-arch@FreeBSD.ORG Mon Nov 24 03:13:17 2014 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 958583A3 for ; Mon, 24 Nov 2014 03:13:17 +0000 (UTC) Received: from mail-wi0-x22d.google.com (mail-wi0-x22d.google.com [IPv6:2a00:1450:400c:c05::22d]) (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 260FFDC6 for ; Mon, 24 Nov 2014 03:13:17 +0000 (UTC) Received: by mail-wi0-f173.google.com with SMTP id r20so4295998wiv.12 for ; Sun, 23 Nov 2014 19:13:15 -0800 (PST) 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=SCckZKqaNoYMPNu37JdlD/OKaIPRXg7kznvqKOa91Uo=; b=ylIiRJ9/ymmAkESxsVWZ4wPnoXDAqAIyppLWuCa5F7RNTo44FzQNeWm5h4iWwhRaVI CfKZewxf0g6Iu53R7eK7OK+iSM6wV6IvXlq4jXP3MRYdtN0GJtcXNxcypUd32pH5WdXW e7Zcvq5NBE8konbIS/WLcZNcyDjzxBDPmZ9hTGReEjWYFEND9GHvdfn40E7bEAQi0xz+ 7DSk7Y16WViFlHBjsGRaz3qVc6IzkRCqovbSvOtQFdfvvjNYEG3XlTVKsjW3fIniuVzH Mp0zHMP+H95QRWE2k+GUAunbs5mkH5Lx/AdNYJPBoVzNyNm8ITQTQ9vmyflSjwtWnqkm zrvw== X-Received: by 10.180.102.135 with SMTP id fo7mr17871443wib.79.1416798795558; Sun, 23 Nov 2014 19:13:15 -0800 (PST) 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 u9sm11859201wjy.37.2014.11.23.19.13.14 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Sun, 23 Nov 2014 19:13:14 -0800 (PST) Date: Mon, 24 Nov 2014 04:13:12 +0100 From: Mateusz Guzik To: Rui Paulo Subject: Re: rarely changing process-wide data vs threads Message-ID: <20141124031312.GA6985@dft-labs.eu> References: <20141123231435.GA32084@dft-labs.eu> <7683D4D1-9458-48D1-A4DF-602E2C4D13C2@me.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <7683D4D1-9458-48D1-A4DF-602E2C4D13C2@me.com> User-Agent: Mutt/1.5.21 (2010-09-15) Cc: freebsd-arch@freebsd.org X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 24 Nov 2014 03:13:17 -0000 On Sun, Nov 23, 2014 at 06:15:58PM -0800, Rui Paulo wrote: > On Nov 23, 2014, at 15:14, Mateusz Guzik wrote: > > There is also a note on filedescs shared between processes. In such > > cases we would abandon this optimisation (dir struct can have a flag to > > note cow is not suitable and lookups need to vref like they do now). > > Are you talking about your optimisation or something that's already there? > I'm saying if the table is shared between processes just vrefing like we do now is the simplest way to go. This feature has to remain operational and there are no problems ensuring so. -- Mateusz Guzik