From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932519AbWEVG5W (ORCPT ); Mon, 22 May 2006 02:57:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932523AbWEVG5V (ORCPT ); Mon, 22 May 2006 02:57:21 -0400 Received: from ozlabs.org ([203.10.76.45]:62593 "EHLO ozlabs.org") by vger.kernel.org with ESMTP id S932519AbWEVG5V (ORCPT ); Mon, 22 May 2006 02:57:21 -0400 Subject: Re: [RFC/PATCH] Make printk work for really early debugging From: Michael Ellerman Reply-To: michael@ellerman.id.au To: Andi Kleen Cc: linux-kernel@vger.kernel.org, Benjamin Herrenschmidt , Andrew Morton In-Reply-To: References: <20060518091410.CC527679F4@ozlabs.org> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-kYuyyCaLr3kuUPtuIXca" Date: Mon, 22 May 2006 16:57:23 +1000 Message-Id: <1148281043.24345.34.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --=-kYuyyCaLr3kuUPtuIXca Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Thu, 2006-05-18 at 15:55 +0200, Andi Kleen wrote: > Michael Ellerman writes: >=20 > > Currently printk is no use for early debugging because it refuses to ac= tually > > print anything to the console unless cpu_online(smp_processor_id()) is = true. >=20 > On x86-64 this is simply solved by setting the boot processor online very= early. I had a closer look at this, and we could actually fudge it so that cpu_online() is true in our early boot code, even though we don't know what cpu we're on. But that kind of begs the question, what does "cpu_online(x)" actually mean? If it doesn't mean percpu data is allocated, what does it mean? cheers --=20 Michael Ellerman IBM OzLabs wwweb: http://michael.ellerman.id.au phone: +61 2 6212 1183 (tie line 70 21183) We do not inherit the earth from our ancestors, we borrow it from our children. - S.M.A.R.T Person --=-kYuyyCaLr3kuUPtuIXca Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2.2 (GNU/Linux) iD8DBQBEcWDTdSjSd0sB4dIRAgpKAJ9HUXsG57lE6PGzs82FVaLHQADRRQCgrN8N GYXBlTCAbLoubF6hbG9GuBc= =rtHC -----END PGP SIGNATURE----- --=-kYuyyCaLr3kuUPtuIXca--