From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <452F03AB.7030505@us.ibm.com> Date: Thu, 12 Oct 2006 20:10:35 -0700 From: Haren Myneni MIME-Version: 1.0 To: Michael Ellerman Subject: Re: [PATCH 1/2] Add support for stopping spus from xmon References: <20061012120310.6B5A967BD5@ozlabs.org> In-Reply-To: <20061012120310.6B5A967BD5@ozlabs.org> Content-Type: text/plain; charset=us-ascii; format=flowed Cc: linuxppc-dev@ozlabs.org, Arnd Bergmann , cbe-oss-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Michael Ellerman wrote: >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. > > > I think, kdump also need stop_spus() functionality when the dump support is included on cell. If so, how about both stop_spus() and start_spus() in platforms/cell/. Thanks Haren