From owner-svn-src-all@freebsd.org Fri Oct 13 20:54:35 2017 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id DC697E2CAD7 for ; Fri, 13 Oct 2017 20:54:35 +0000 (UTC) (envelope-from ian@freebsd.org) Received: from pmta2.delivery6.ore.mailhop.org (pmta2.delivery6.ore.mailhop.org [54.200.129.228]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id BDE1074940 for ; Fri, 13 Oct 2017 20:54:35 +0000 (UTC) (envelope-from ian@freebsd.org) X-MHO-User: 9dff4aeb-b058-11e7-b50b-53dc5ecda239 X-Report-Abuse-To: https://support.duocircle.com/support/solutions/articles/5000540958-duocircle-standard-smtp-abuse-information X-Originating-IP: 73.78.92.27 X-Mail-Handler: DuoCircle Outbound SMTP Received: from ilsoft.org (unknown [73.78.92.27]) by outbound2.ore.mailhop.org (Halon) with ESMTPSA id 9dff4aeb-b058-11e7-b50b-53dc5ecda239; Fri, 13 Oct 2017 20:53:51 +0000 (UTC) Received: from rev (rev [172.22.42.240]) by ilsoft.org (8.15.2/8.15.2) with ESMTP id v9DKsRQ7001870; Fri, 13 Oct 2017 14:54:27 -0600 (MDT) (envelope-from ian@freebsd.org) Message-ID: <1507928067.8386.84.camel@freebsd.org> Subject: Re: svn commit: r324609 - head/sys/sys From: Ian Lepore To: Mateusz Guzik , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Date: Fri, 13 Oct 2017 14:54:27 -0600 In-Reply-To: <201710132031.v9DKVueS089009@repo.freebsd.org> References: <201710132031.v9DKVueS089009@repo.freebsd.org> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.18.5.1 FreeBSD GNOME Team Port Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 13 Oct 2017 20:54:36 -0000 On Fri, 2017-10-13 at 20:31 +0000, Mateusz Guzik wrote: > Author: mjg > Date: Fri Oct 13 20:31:56 2017 > New Revision: 324609 > URL: https://svnweb.freebsd.org/changeset/base/324609 > > Log: >   mtx: change MTX_UNOWNED from 4 to 0 >    >   The value is spread all over the kernel and zeroing a register is >   cheaper/shorter than setting it up to an arbitrary value. >    >   Reduces amd64 GENERIC-NODEBUG .text size by 0.4%. >    >   MFC after: 1 week > If you MFC this, won't that break the ABI for modules compiled against earlier versions of the branch? Also, won't this trigger a need to recompile out of tree modules such as video drivers, virtualbox, etc?  Does that need an UPDATING entry? -- Ian