Date: Mon, 14 Jul 2014 21:47:25 +0300 From: Konstantin Belousov <kostikbel@gmail.com> To: Nathan Whitehorn <nwhitehorn@freebsd.org> Cc: svn-src-head@FreeBSD.org, svn-src-all@FreeBSD.org, src-committers@FreeBSD.org Subject: Re: svn commit: r268624 - head/sys/dev/vt/hw/efifb Message-ID: <20140714184725.GL93733@kib.kiev.ua> In-Reply-To: <53C424B7.7070403@freebsd.org> References: <201407141742.s6EHgMNt094168@svn.freebsd.org> <20140714175345.GK93733@kib.kiev.ua> <53C424B7.7070403@freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
--qt/8o3zVjmkHzDiC Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Jul 14, 2014 at 11:43:03AM -0700, Nathan Whitehorn wrote: >=20 > On 07/14/14 10:53, Konstantin Belousov wrote: > > On Mon, Jul 14, 2014 at 05:42:22PM +0000, Nathan Whitehorn wrote: > >> + info->fb_vbase =3D (intptr_t)pmap_mapdev_attr(info->fb_pbase, > >> + info->fb_size, VM_MEMATTR_WRITE_COMBINING); > >> +} > >> + > > Could you use pmap_change_attr() ? This would save some KVA. >=20 > Does that work with the direct map? I'm pretty hesitant to muck with the= =20 > direct map region this way... Yes, it works on direct map. Note that Intel explicitely states that the behaviour is undefined if the same physical page is mapped with differrent caching attributes. At least some revisions of Pentium IV hang in this situation. We keep direct map mapping attributes consistent with other mappings. --qt/8o3zVjmkHzDiC Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBAgAGBQJTxCW9AAoJEJDCuSvBvK1B5i8P/0Mmj5xRf9mpoIIJ2DVNWcff WycF2aPOtfwqFkWsnGphyAHedRdXTY2mPXfrTGdaSejKhGJ/wVZ+MCAehqKlk9RP voUuoJO6EQcfzkl7QmipJFJuIhg5Pj8oOxYEXFrEG16yfDKOlI1NMGeks5ryQnT2 B4BJi15PG4F0sYFSARDaTqkmY0RYeN/2gCxge5mutfLkfk2sDwiQC2Ds8R94zW8p ToYJ1P4MROzw8bE1AMZuM0g/wVMql55jL/TSDd8k50HfRQTQbTK1hvENocFL4dsK FY9tLNjGhMBjk0tAsgqd0Pwy3ded0MNlJ2cfDCshf0fP3PBzuNTNfIuo4d+o01ZH jwp4q16vPyJLFH6YnsWBI+KvFttrzOvFqDe7h+fDuFY8woZ6IUvcuqEQ/oivy3OO Ot+3mqYKIAZoFlg/4PKHhco2lfeKri8ggtESJhbhjwvSUdw+u1MzeeLrPmomVUg+ jeUdSnVuFvvVx2z0qYrZn6PVL2thEqOJ5nyt8W5ziIwxvtA/0AHpvoYI8DKlzT7V EHI6FTHG1Ym/KKybbroZ8XXGbATjDXpdDDez8o7bya8iNoQcIofdIutDp9aoKA51 HyaC6HQlMn3Oud1/jQJRGDzR3YJz25qBONit8mnK1ER6BS8UaG1dgdDxgbEAWiH8 JKuWZQOVsajGoTdz7Oau =vSHF -----END PGP SIGNATURE----- --qt/8o3zVjmkHzDiC--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20140714184725.GL93733>