From owner-svn-src-head@FreeBSD.ORG Wed Sep 30 13:43:41 2009 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EB261106568F; Wed, 30 Sep 2009 13:43:41 +0000 (UTC) (envelope-from ivoras@gmail.com) Received: from mail-ew0-f209.google.com (mail-ew0-f209.google.com [209.85.219.209]) by mx1.freebsd.org (Postfix) with ESMTP id 0B9588FC0A; Wed, 30 Sep 2009 13:43:39 +0000 (UTC) Received: by ewy5 with SMTP id 5so505081ewy.36 for ; Wed, 30 Sep 2009 06:43:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:from:date:x-google-sender-auth:message-id:subject:to:cc :content-type:content-transfer-encoding; bh=uKf6lMKnBOu8mFg6Svt7Hf4FQp9nT1JUpxHViSAqaXU=; b=nDYlnPkFltzItPjvvHPr/qxHWLo1uEBZSDrhjqRFb4T/7rk/9HRw99V/6VvVAq+Lz+ 9YVrNgHnqGKX9HotuDFoNF/F6DG2m+Vva4es+snHC0QXL5MZsDY53mg3PyZxp9bhbyMh tKLOo2y/mBHZVoU1EhqcNsYUvQKYsDGcCy0p8= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:from:date :x-google-sender-auth:message-id:subject:to:cc:content-type :content-transfer-encoding; b=MnEG4CwbLlhz0tTCRDKKba9Qy5Ap+d4flEwTLSZ6lKA0HBZp/QhEcI2bUZlg/40bV7 SSWKx8vwfligySZ7ipbCmfCHaM0ZnSFfGuWOTcg7Hqs1yCGkBKFcCd5awLiuexvxoZem BGADYCJHAqVj6IMq/zMZvPZ0pkKyyu1+aNGK0= MIME-Version: 1.0 Sender: ivoras@gmail.com Received: by 10.216.6.142 with SMTP id 14mr1449895wen.142.1254318219107; Wed, 30 Sep 2009 06:43:39 -0700 (PDT) In-Reply-To: <200909301326.n8UDQVB1016396@svn.freebsd.org> References: <200909301326.n8UDQVB1016396@svn.freebsd.org> From: Ivan Voras Date: Wed, 30 Sep 2009 15:43:19 +0200 X-Google-Sender-Auth: 43ff06b6ff1f0a53 Message-ID: <9bbcef730909300643k56e40be9xc8b8287dc2971ac3@mail.gmail.com> To: Attilio Rao Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r197643 - in head/sys: kern sys X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 30 Sep 2009 13:43:42 -0000 2009/9/30 Attilio Rao : > Author: attilio > Date: Wed Sep 30 13:26:31 2009 > New Revision: 197643 > URL: http://svn.freebsd.org/changeset/base/197643 > > Log: > =C2=A0When releasing a read/shared lock we need to use a write memory bar= rier > =C2=A0in order to avoid, on architectures which doesn't have strong order= ed > =C2=A0writes, CPU instructions reordering. Will this influence performance on those architecture that do?