From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: Does there exists any 32bit-only PARISC SMP machines? Date: Fri, 30 Aug 2013 06:42:21 +0400 Message-ID: <1377830541.2331.5.camel@dabdike> References: <521F9848.4010404@gmx.de> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-15" Cc: linux-parisc To: Helge Deller Return-path: In-Reply-To: <521F9848.4010404@gmx.de> List-ID: List-Id: linux-parisc.vger.kernel.org On Thu, 2013-08-29 at 20:51 +0200, Helge Deller wrote: > Hi all, > > I was asked by the debian kernel team to drop on parisc the UP kernels > and only provide SMP kernels even for UP-machines. > For 64bit it might make sense to only ship a 64bit SMP kernel, but I'm > not sure if it makes sense for 32bit kernels. > One major question would be, if there exists any 32bit parisc machines > which support multiple CPUs at all? > If not, then it would make sense to drop the 32bit SMP kernels > instead. > > So, are there any 32bit SMP machines out there? Yes, the J class systems have some 32 bit only SMP boxes (well one, the J210XC, I think) ... mostly with 7200 and above processors. > Any other thoughts on this topic? SMP will certainly work. The main problem with SMP on UP is the unnecessary spinlock cost. I think given there's very few owners of J class SMP 32 bit systems, 32 bit UP and 64 bit SMP is OK. James