From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH 1/2] Add support for stopping spus from xmon From: Michael Ellerman To: Haren Myneni In-Reply-To: <452F03AB.7030505@us.ibm.com> References: <20061012120310.6B5A967BD5@ozlabs.org> <452F03AB.7030505@us.ibm.com> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-7vXhKxOwSFwg9z838oWG" Date: Wed, 18 Oct 2006 17:16:33 +1000 Message-Id: <1161155793.7906.21.camel@localhost.localdomain> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, Arnd Bergmann , cbe-oss-dev@ozlabs.org Reply-To: michael@ellerman.id.au List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --=-7vXhKxOwSFwg9z838oWG Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Thu, 2006-10-12 at 20:10 -0700, Haren Myneni wrote: > Michael Ellerman wrote: >=20 > >This patch adds support for stopping, and restarting, spus > >from xmon. We use the spu master runcntl bit to stop execution, > >this is apparently the "right" way to control spu execution and > >spufs will be changed in the future to use this bit. > > > >Testing has shown that to restart execution we have to turn the > >master runcntl bit on and also rewrite the spu runcntl bit, even > >if it is already set to 1 (running). > > > >Stopping spus is triggered by the xmon command 'ss' - "spus stop" > >perhaps. Restarting them is triggered via 'sr'. Restart doesn't > >start execution on spus unless they were running prior to being > >stopped by xmon. > > > >Walking the spu->full_list in xmon after a panic, would mean > >corruption of any spu struct would make all the others > >inaccessible. To avoid this, and also to make the next patch > >easier, we cache pointers to all spus during boot. > > > >We attempt to catch and recover from errors while stopping and > >restarting the spus, but as with most xmon functionality there are > >no guarantees that performing these operations won't crash xmon > >itself. > > > > =20 > > > I think, kdump also need stop_spus() functionality when the dump support=20 > is included on cell. If so, how about both stop_spus() and start_spus()=20 > in platforms/cell/. Good point. We haven't got that far with kdump on cell so I hadn't thought of it. We won't need start_spus(), but we will need something to stop spus for kdump. I'll leave it for now, but keep it in mind for when we get kdump going on cell. cheers --=20 Michael Ellerman OzLabs, IBM Australia Development Lab 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 --=-7vXhKxOwSFwg9z838oWG 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) iD8DBQBFNdTRdSjSd0sB4dIRAu3FAKC6yTh1pw1nUVpm/XyK6egcqbWbHwCgq5we BJIhMQFWWcoti6Q57KLuDbE= =aq6k -----END PGP SIGNATURE----- --=-7vXhKxOwSFwg9z838oWG--