From owner-freebsd-arch@FreeBSD.ORG Mon Nov 24 23:22:29 2014 Return-Path: Delivered-To: arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 074DFDD9 for ; Mon, 24 Nov 2014 23:22:29 +0000 (UTC) Received: from mail-pd0-f174.google.com (mail-pd0-f174.google.com [209.85.192.174]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id C0342267 for ; Mon, 24 Nov 2014 23:22:28 +0000 (UTC) Received: by mail-pd0-f174.google.com with SMTP id w10so10610409pde.5 for ; Mon, 24 Nov 2014 15:22:27 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:sender:subject:mime-version:content-type:from :in-reply-to:date:cc:message-id:references:to; bh=w8qZvWxjpbySHjEowuHNHKPEJBoHoFak+k9s+Qx8ErA=; b=STEE2zQJd1EfP1kS4PKmJ+FQdmVqS/WyN9/4j7eDtIdMGg2iEm4qQJTAPv34UbSU4I ggXowN1FRyA4UxmG/4DezgXWFK6FexmJ0ubmbr9dp51JsWcBEemtkALP5aObXbpNjTjQ djSF+knfsMcPXtEkGu6cUsf2Kwk3xnasA6PHFTV2XM037sZ7/yuZrf40q+SoU/z66zue Zps7rVZXq64+Zifl4VO4onlo8sW4fywCqmyeGiiPz8Btycd3Ng/U6t1K60iNee/mgqg+ RcbBMRStbpPk6ElZ1GIkm6Jh3utcyQZlIqOHlsjZ4MPMINPvNY9C+zCovng3iYLs+Ijs fgBw== X-Gm-Message-State: ALoCoQmG6O5vZQRaPSYpVYJrSxqixUyjS+qpQwy1FcNtJTF8k9W0+eyA/hd/uqHoy7HgRrypv515 X-Received: by 10.66.189.101 with SMTP id gh5mr37599476pac.56.1416871347793; Mon, 24 Nov 2014 15:22:27 -0800 (PST) Received: from [10.64.26.139] ([69.53.236.236]) by mx.google.com with ESMTPSA id y10sm13406931pdq.15.2014.11.24.15.22.26 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 24 Nov 2014 15:22:26 -0800 (PST) Sender: Warner Losh Subject: Re: svn commit: r274739 - head/sys/mips/conf Mime-Version: 1.0 (Mac OS X Mail 8.1 \(1993\)) Content-Type: multipart/signed; boundary="Apple-Mail=_3450DD1C-F153-4F44-8384-982126E9CCBB"; protocol="application/pgp-signature"; micalg=pgp-sha512 X-Pgp-Agent: GPGMail 2.5b2 From: Warner Losh In-Reply-To: <86wq6k9okk.fsf@nine.des.no> Date: Mon, 24 Nov 2014 16:22:23 -0700 Message-Id: <4C2BD093-BEA2-47F9-B575-90342712E9B2@bsdimp.com> References: <201411200552.sAK5qnXP063073@svn.freebsd.org> <20141120084832.GE24601@funkthat.com> <20141121092245.GI99957@funkthat.com> <1416582989.1147.250.camel@revolution.hippie.lan> <026FEB8A-CA8C-472F-A8E4-DA3D0AC44B34@grondar.org> <1416596266.1147.290.camel@revolution.hippie.lan> <1416598889.1147.297.camel@revolution.hippie.lan> <86egsvueqk.fsf@nine.des.no> <1416691274.1147.339.camel@revolution.hippie.lan> <398A380D-49AF-480C-8842-8835F81EF641@grondar.org> <1416806894.1147.362.camel@revolution.hippie.lan> <18B8A926-59C0-49B4-ADA3-A11688609852@grondar.org> <1416841268.1147.386.camel@revolution.hippie.lan> <86wq6k9okk.fsf@nine.des.no> To: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= X-Mailer: Apple Mail (2.1993) Cc: arch@freebsd.org, Ian Lepore , Mark R V Murray X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 24 Nov 2014 23:22:29 -0000 --Apple-Mail=_3450DD1C-F153-4F44-8384-982126E9CCBB Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 > On Nov 24, 2014, at 4:16 PM, Dag-Erling Sm=C3=B8rgrav = wrote: >=20 > Mark R V Murray writes: >=20 >>> On 24 Nov 2014, at 15:01, Ian Lepore wrote: >>>=20 >>>=20 >>> The logging change was pretty simple: >>>=20 >>> Index: kern/subr_bus.c >>=20 >> Thanks. >>=20 >>> The low number of devices is pretty typical. Sometimes there'll be >>> another uart. Sometimes an i2c eeprom. >>=20 >> OK - a good example of a low-entropy system then. >>=20 >>> I have no idea what's up with the first 3 unchanging numbers, but I >>> suspect a big part of the explanation for the other numbers is the = 32KHz >>> clock it's getting the numbers from. There used to be a clock = running >>> at about 2.8MHz, but the source code for that driver seems to have >>> disappeared from FreeBSD at some point between 8.x and -current. >>=20 >> What really bothers me is that these should be the difference between >> 2 essentially similar numbers; times not all that far apart, yet some >> of the numbers are truly massive. >=20 > They're not just massive, they're preposterous, as is the fact that = most > of them are absolutely identical, or just one bit off, from one run to > the next. My best guess is that get_cyclecount() is broken. What=E2=80=99s the minimum specs required for get_cyclecount()? Not all = of the boxes that Ian was posting about have high-resolution time-keeping = counters in hardware=E2=80=A6 Maybe there=E2=80=99s some underlying expectation = for this function that these systems either aren=E2=80=99t providing or can=E2=80=99t = provide. Warner --Apple-Mail=_3450DD1C-F153-4F44-8384-982126E9CCBB Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP using GPGMail -----BEGIN PGP SIGNATURE----- Comment: GPGTools - https://gpgtools.org iQIcBAEBCgAGBQJUc72wAAoJEGwc0Sh9sBEAeE8P/ibUhZZbEF1MhrNTZ0YbuDvf kLlRnnjz+UKUMSN9cQZQD2m+L1Y+rmHV7BLdcAFH2CiRF2pBXvkM/gnR8CWLSulC mFSyLWE77k56ko2cEOX/xTyyKV9laZGABtwts78GxXFAIhbvW1pqvqMGWMGJwZ4W Q6F6dr8PRCBCIKclK1jz1uV/3wRVPSxORRvmeL6N8deyeWtTE6G1qpAOlrk6A/DU aneDmOxZ48WVUie2u8NVPoGxLirTNK9kV/QojmYU93nWY2Jh+kLWy+2w6xd1wP/N G2kuCD8hxoQA6yRdov2KlvamSzeIgvmkPQCzN+WMWm5/bk0LbA5bEsjGAWtNm9BN cdEP3RjOBFmnSX5Sqq9Yrys0gaIVFvGzrG2v4IoZYvpgdB/Bg+y7IZ71hYPqfLWq Ck0ZbFY8rQavds7ZyxShbVrWGYnBWsmUAtmoWCMQCxgvWIl+ebSx5O5qg7b8h1fg Uqc2rPx7oEV1At2NyPut5a691tNMdlOQG9TUo0tAq4ptBKJMhXeH84JR8E3621IM /6qz9GqfNPmdg8v4IV7GtfPY+tQaaRIGsknsZWeyI0zvLBlR6B5JBOAYz7Nr+hYs ukAQvYl8G2IdQsZQqo6ZYfo78dSMTWf25Y+YEzabEnpNtz1BQ7YABTDERBxV10tm no5xGOcsGB1lq2stdg+A =9can -----END PGP SIGNATURE----- --Apple-Mail=_3450DD1C-F153-4F44-8384-982126E9CCBB--