From owner-svn-src-all@FreeBSD.ORG Tue Jan 8 17:21:44 2013 Return-Path: Delivered-To: svn-src-all@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id DDD536DF; Tue, 8 Jan 2013 17:21:44 +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 555BCE50; Tue, 8 Jan 2013 17:21:44 +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 r08HLZfQ023555; Tue, 8 Jan 2013 19:21:35 +0200 (EET) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.7.4 kib.kiev.ua r08HLZfQ023555 Received: (from kostik@localhost) by tom.home (8.14.6/8.14.6/Submit) id r08HLZlh023554; Tue, 8 Jan 2013 19:21:35 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Tue, 8 Jan 2013 19:21:35 +0200 From: Konstantin Belousov To: Ian Lepore Subject: Re: svn commit: r245147 - head/sys/arm/include Message-ID: <20130108172135.GA2561@kib.kiev.ua> References: <201301080240.r082eKVq080302@svn.freebsd.org> <20130108030022.GC82219@kib.kiev.ua> <50EBA947.1030902@freebsd.org> <20130108155641.GG82219@kib.kiev.ua> <1357664471.1088.131.camel@revolution.hippie.lan> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="uAKRQypu60I7Lcqm" Content-Disposition: inline In-Reply-To: <1357664471.1088.131.camel@revolution.hippie.lan> 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, Oleksandr Tymoshenko , svn-src-all@FreeBSD.org, src-committers@FreeBSD.org X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.14 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: Tue, 08 Jan 2013 17:21:44 -0000 --uAKRQypu60I7Lcqm Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jan 08, 2013 at 10:01:11AM -0700, Ian Lepore wrote: > I'm just learning the armv6/v7 stuff myself right now, but I can answer > your question for our current armv4/v5 implementation... >=20 > When there is more than one mapping of a page in v4/v5 and any one of > those mappings is writable, then the pmap.c code changes all existing > mappings to be uncacheable to maintain coherency. If the writable > mapping is removed and all that remains are read/exec mappings, the > existing mappings are made cacheable again. Yes, that's just as > inefficient and expensive as it sounds. :) Interesting, so the arm/pmap.c in fact maintain pv entries even for the unmanaged pages and kernel mappings ? But this approach, requiring pv entries for the kernel mappings, makes kernel pv entries non-reclamable on the low memory condition. In fact, I cannot find any traces of the pv reclaim in the arm/pmap.c. --uAKRQypu60I7Lcqm Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (FreeBSD) iQIcBAEBAgAGBQJQ7FWeAAoJEJDCuSvBvK1B2QIP/RjN9Fome0N2bCdPF1iPpHdo 61hXwZuKgOf24W8EVKf19vJxd9OXrLiCBN/gAqx5fXStF2u3F8wjHN2Kfjsqh030 44ar2ccg2wuQ2rK1fHU9/rBryC2J4L9XyY6GReDW92T84QOevyDm9oY8k3nNW12t AVB3sqde6jdNvpYp9wzR8k6FRDUX3nRT9rsaEBO10YxIzDJvRiJuZoAGTidkIxeg Me2geRSGYJnq82Ot8ev8kRVsqOSAGWqSf+04jRoPx0etHa42gcWBdFEAfjogiZHp xRvyf0wnLlke+3rAllJRQWBTRv9KgPwkjVFdaID5JaS6XcgvHkd3Er2arUv2qpdI rZRk2Pbgo2N36r+dFY5WtY+p8sB193WwhZy5dPpzE6NDkVSF+dkhCMrNzsdmorpS 8K/dETIkTiMe3enGuHZLophS0wlUXBEJqoRX09lHzZpxtqpFn8JvMCxNn1bKfp+W gxbEOdSz12jgXzd7idUv4tsR5z24afjVv7QZZpp9JvBccNP037Qa7tQ36a7ZpO6L tKjcAHQ6zKDRWF78QUVOwb4c/v4xRjrfRFd1+DTbyj3LdzzyBrtyhh67mNku+yhb glbVuXuLHmmK6h9Hf1gI05oBCr7rti+22Siuq5nJlVB7EhOBdEMBVnfsEeiGqfx9 PYPp+8UGHC2avldRqV7u =4a0+ -----END PGP SIGNATURE----- --uAKRQypu60I7Lcqm--