From owner-svn-src-head@FreeBSD.ORG Fri Jan 18 04:03:44 2013 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 5047890A; Fri, 18 Jan 2013 04:03:44 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) by mx1.freebsd.org (Postfix) with ESMTP id AACF1A52; Fri, 18 Jan 2013 04:03:43 +0000 (UTC) Received: from tom.home (kostik@localhost [127.0.0.1]) by kib.kiev.ua (8.14.6/8.14.6) with ESMTP id r0I43WwW054686; Fri, 18 Jan 2013 06:03:32 +0200 (EET) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.7.4 kib.kiev.ua r0I43WwW054686 Received: (from kostik@localhost) by tom.home (8.14.6/8.14.6/Submit) id r0I43WKx054685; Fri, 18 Jan 2013 06:03:32 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Fri, 18 Jan 2013 06:03:32 +0200 From: Konstantin Belousov To: John Baldwin Subject: Re: svn commit: r245577 - in head/sys: amd64/amd64 i386/i386 x86/x86 Message-ID: <20130118040332.GT2522@kib.kiev.ua> References: <201301172132.r0HLWQHD004835@svn.freebsd.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="zpd1bWBxfrI+71+6" Content-Disposition: inline In-Reply-To: <201301172132.r0HLWQHD004835@svn.freebsd.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-Spam-Status: No, score=-2.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on tom.home Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.14 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: Fri, 18 Jan 2013 04:03:44 -0000 --zpd1bWBxfrI+71+6 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jan 17, 2013 at 09:32:26PM +0000, John Baldwin wrote: > Author: jhb > Date: Thu Jan 17 21:32:25 2013 > New Revision: 245577 > URL: http://svnweb.freebsd.org/changeset/base/245577 >=20 > Log: > Don't attempt to use clflush on the local APIC register window. Various > CPUs exhibit bad behavior if this is done (Intel Errata AAJ3, hangs on > Pentium-M, and trashing of the local APIC registers on a VIA C7). The > local APIC is implicitly mapped UC already via MTRRs, so the clflush is= n't > necessary anyway. > =20 > MFC after: 2 weeks I am curious, was there a case where the clflush was really executed on the LAPIC register window with the pristine HEAD code ? I think that there is no Intel processors which support clflush instruction and do not have self-snoop. On the other hand, please note that the same change could be due for the pmap_invalidate_cache_pages(). Unlike pmap_invalidate_cache_range(), _pages() uses clflush unconditionally on purpose, since it is intended for devices which do not snoop. --zpd1bWBxfrI+71+6 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (FreeBSD) iQIcBAEBAgAGBQJQ+MmTAAoJEJDCuSvBvK1BYCgQAJq2wMsms/Y/j8FjwWynSp0n LL+4XHq6fVH8wQEr27Y2poVmqjPGb38SprQDzzA/bk7/ihF1KX8UeYYRKo4J2PvI j9wErfFOpvoLh8RmXXHsjW0rnVmENnvKv3V7ylRSfVxCSolivIoTBfOLnPaW6ZCC GT8WrDmyWWMp5BLl+6uvLkCYSpowIPRA+TGEIqJ59iKFFpoM8X+00mi6lBe1jLH6 U5g1HPcFG+s+1K5P1gfNM5FARxq30rku2pZtbhP6xoGrNbIPYoEFynJNUXYz5wsM WfubWKhmqWrIAYdgLoMAdtV3Op9847LHo8k+QX+quUHM3sQpDc7EpUAHDl37dwgN vUp3KbiYNUpPO4Y15wPfTCtSJuYB5zletPHPSRkwB5wIsqtcBLZszUkEBHX4rE64 8FyyPei5F43RWv4VphMWRX+xCrAvYMkrUb81p4q24i5drmDUmrnEzUyKmnJHPmpO 8pbcEfrkog2WdmN512jeEg/0fHl7G2PQROpK6+cgad0U1I7sIt5mqbgrfg7nY8a0 bdLQL6KCCZP2hSkyUIiQ1S+RdPemYsknnq1vEc43z5ecBXEdw++pAzXp98DhEKWv cANU7sR5cDCTrdhkxPNV74T1VsgjMGXnkp/8g2usAdSCVFvHzGZWySwRXKFi+eV8 wlsg7NGTR2D9ZtbyHz8n =PmLn -----END PGP SIGNATURE----- --zpd1bWBxfrI+71+6--