From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mtagate2.de.ibm.com ([195.212.29.151]:40673 "EHLO mtagate2.de.ibm.com") by vger.kernel.org with ESMTP id S262125AbULCJnc (ORCPT ); Fri, 3 Dec 2004 04:43:32 -0500 Received: from d12nrmr1507.megacenter.de.ibm.com (d12nrmr1507.megacenter.de.ibm.com [9.149.167.1]) by mtagate2.de.ibm.com (8.12.10/8.12.10) with ESMTP id iB39hSbP170660 for ; Fri, 3 Dec 2004 09:43:29 GMT Received: from d12av02.megacenter.de.ibm.com (d12av02.megacenter.de.ibm.com [9.149.165.228]) by d12nrmr1507.megacenter.de.ibm.com (8.12.10/NCO/VER6.6) with ESMTP id iB39hNG8123056 for ; Fri, 3 Dec 2004 10:43:23 +0100 Received: from d12av02.megacenter.de.ibm.com (loopback [127.0.0.1]) by d12av02.megacenter.de.ibm.com (8.12.11/8.12.11) with ESMTP id iB39hRRG001645 for ; Fri, 3 Dec 2004 10:43:27 +0100 From: Arnd Bergmann Subject: Re: other platforms interested in in-kernel unwinder? Date: Fri, 3 Dec 2004 10:37:22 +0100 References: <16815.21943.55627.572012@napali.hpl.hp.com> In-Reply-To: <16815.21943.55627.572012@napali.hpl.hp.com> MIME-Version: 1.0 Message-Id: <200412031037.22445.arnd@arndb.de> Content-Type: multipart/signed; protocol="application/pgp-signature"; micalg=pgp-sha1; boundary="Boundary-02=_SPDsBzsg0ImUR7c"; charset="iso-8859-15" Content-Transfer-Encoding: 7bit To: davidm@hpl.hp.com Cc: linux-arch@vger.kernel.org, davidm@napali.hpl.hp.com, Wolfgang Gellerich List-ID: --Boundary-02=_SPDsBzsg0ImUR7c Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Dunnersdag 02 Dezember 2004 18:49, David Mosberger wrote: > So, how does this sound? =A0Any interest from say, x86{-64}, PPC, SPARC, > or any other arch maintainer? I think it doesn't make much sense for unwinding s390 kernel stacks, since they already have reliable back traces trough the backchain pointers. In particular, those pointers are needed anyway for easy unwinding by hand when debugging in z/VM. My limited experience on ppc64 suggests that the situation there is very similar. OTOH, I've heard that oprofile is unwinding user stacks to get call graph information. For that purpose, a kernel unwinder might turn out very valuable on many architectures, including those that use a backchain pointer in kernel but not in user space. Arnd <>< --Boundary-02=_SPDsBzsg0ImUR7c Content-Type: application/pgp-signature Content-Description: signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) iD8DBQBBsDPS5t5GS2LDRf4RAv5dAJ9SpQGAmqDh1ud5jgn3nMdmA86pCACbBgwp 17kDQlJku4ljOuEQCO/lrHk= =ZcbE -----END PGP SIGNATURE----- --Boundary-02=_SPDsBzsg0ImUR7c--