From owner-freebsd-mips@freebsd.org Sun Nov 13 18:42:46 2016 Return-Path: Delivered-To: freebsd-mips@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 9555EC4035B for ; Sun, 13 Nov 2016 18:42:46 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: from mail-it0-x236.google.com (mail-it0-x236.google.com [IPv6:2607:f8b0:4001:c0b::236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 5C18A18F9; Sun, 13 Nov 2016 18:42:46 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: by mail-it0-x236.google.com with SMTP id c20so38939915itb.0; Sun, 13 Nov 2016 10:42:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=rxfnVWjcLFOgPlPSu5DaDj4vaI7UqoDAoLsgrH/QhNw=; b=u2D7rsLIGVCYIxMmDBpjPgib4+4gQQNH8ojh/U2cF+Y+1kt+MlKOG7ZSM7xFf2mXNj +lzSy6CFuuNygf5hhAgUV7jPC/UI2qVAX62PLpr0a7fe4f38qDBwssmGvvWhNH/GuEAO fcSO4x70sV3yWcC3Abx6ddvVbtvkCYOiEEs9uz8FnDaLgsYz1XDR1lMBAbMtZtb+flR0 NapW6zDoqz1ltTcDN155RfcoNYzPKEU5XU9W+lc59V3DauIuMtzGF7N/OYEeauuhXZfV ITSYl0Jtes0x2TmX1ldnLYQKnkY7+neMkNCQHTe12BT5LRIXWCdXLCBzLXpM4cZzCBkn Fs7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=rxfnVWjcLFOgPlPSu5DaDj4vaI7UqoDAoLsgrH/QhNw=; b=lBxrfp7Eyw+QP7LEwD6HiJm5D4qKOTEGb7U3Mfmv61DXgRaZ66/5cX/E7f15FEM2rA NwvLDZgBL0zxi6zWZeiPfSgI9s9G/Vf45H+MD/NmTHutwJWQ31md1LI70j8ECfvvj1bi /MPZxSYO+862HEThQZjvAChJ+uzLBJen09P2v0yUmWRz8SsRsTVGi74qCbKBMmgyEUkG fJis2OkDVLt1NzIN73VD1x+UUu7O71dddTE3jNH5PD7+STTz3WRGKl6AhPfbDVsX4+hV mfLtugYtePsSVpO8Dv08dYTXUHnwNd6dbAiWlwL036oyX470BpBZ6O7MnSB+LTwp4Qbp IzYQ== X-Gm-Message-State: ABUngveTjIlMgkF0lne3kFTV0fi7KFCjfFM8Nl5ehvDQv3DV1hFgYeNegcXDOPEaaKZyF9cvXeJ2UqK4F2VNVw== X-Received: by 10.36.58.85 with SMTP id m82mr702194itm.29.1479062565810; Sun, 13 Nov 2016 10:42:45 -0800 (PST) MIME-Version: 1.0 Received: by 10.36.39.134 with HTTP; Sun, 13 Nov 2016 10:42:44 -0800 (PST) In-Reply-To: <20161113161548.GK54029@kib.kiev.ua> References: <201610191109.u9JB9TTC002727@repo.freebsd.org> <20161113065851.GD54029@kib.kiev.ua> <20161113071911.GF54029@kib.kiev.ua> <20161113075557.GH54029@kib.kiev.ua> <71C512CD-0FB6-40D8-B46C-30467A245693@bsdimp.com> <20161113161548.GK54029@kib.kiev.ua> From: Adrian Chadd Date: Sun, 13 Nov 2016 10:42:44 -0800 Message-ID: Subject: Re: svn commit: r307626 - head/sys/ufs/ffs To: Konstantin Belousov Cc: Juli Mallett , Warner Losh , Warner Losh , "freebsd-mips@freebsd.org" Content-Type: text/plain; charset=UTF-8 X-BeenThere: freebsd-mips@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Porting FreeBSD to MIPS List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 13 Nov 2016 18:42:46 -0000 On 13 November 2016 at 08:15, Konstantin Belousov wrote: > Sparc64 also has the aliasing issue, and AFAIR sparc64 pmap does allow > more than one mapping of the same page at conflicting ('differently > colored') addresses. But indeed, each mapping (not only the managed > mappings) are tracked, and all mappings are demoted to uncached if > conflict is created. Hm, so where's that been happening? Why hasn't this happened in the mips32 world until this commit? >> It'd be neat to see this happen; I'm not sure who would really do it. >> It's tricky to get right. We may support other architectures that >> have complete or partial solutions to this, but I deliberately don't >> know about them. Stare at code dealing with VIPT ARM systems, or pmap >> on other BSDs that have sunk more effort into all the edge cases of >> VIPT MIPS systems. > For arm, only arm v4 pmap deals with VIPT aliasing. Arm v6 assumes that > the system is free from that bug. -adrian