From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from fallback.mail.elte.hu (fallback.mail.elte.hu [157.181.151.13]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 3E99DB6FAB for ; Wed, 16 Mar 2011 23:51:30 +1100 (EST) Date: Wed, 16 Mar 2011 13:50:53 +0100 From: Ingo Molnar To: Anton Blanchard Subject: Re: [PATCH] powerpc: perf: Handle events that raise an exception without overflowing Message-ID: <20110316125053.GA7387@elte.hu> References: <20110309143842.6c22845e@kryten> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20110309143842.6c22845e@kryten> Cc: linuxppc-dev@lists.ozlabs.org, paulus@samba.org, a.p.zijlstra@chello.nl, acme@ghostprotocols.net List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , * Anton Blanchard wrote: > > Events on POWER7 can roll back if a speculative event doesn't > eventually complete. Unfortunately in some rare cases they will > raise a performance monitor exception. We need to catch this to > ensure we reset the PMC. In all cases the PMC will be 256 or less > cycles from overflow. > > Signed-off-by: Anton Blanchard > Cc: stable@kernel.org > --- > > I would prefer not to add the PVR check, but I think we want to limit > this workaround to POWER7. Would a cpu feature be preferable? There was no objection from the PowerPC folks so i'll send this fix Linuswards, ok? Thanks, Ingo