From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Mosberger Date: Tue, 04 May 2004 18:20:11 +0000 Subject: Re: [RFC] I/O MCA recovery Message-Id: <16535.57051.469403.11537@napali.hpl.hp.com> List-Id: References: <200405040954.09524.jbarnes@engr.sgi.com> In-Reply-To: <200405040954.09524.jbarnes@engr.sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org >>>>> On Tue, 4 May 2004 11:07:41 -0700, Jesse Barnes said: Jesse> On Tuesday, May 4, 2004 10:43 am, David Mosberger wrote: >> Eh, I/O space is required to soft-fail, isn't it? Jesse> I thought so too, but I haven't been able to find the spec Jesse> that contains that requirement. It's certainly implied. >> Why can't you hide this in the platform-specific inX/outX routines? I >> suppose it would be very slow to drain MCAs after every inX/outX, but >> you'd have to do the slow part only once, until you know whether or >> not the given I/O address is safe. Jesse> This is I/O initiated by userspace loads/stores, so unless I Jesse> wrap every in/out with some sort of ioctl or something, those Jesse> won't help me. User-level accesses are mapped via the MMU so you could always intercept the page-faults. Jesse> Also, with this scheme, we could potentially recover from Jesse> regular read/writes too. _If_ there is an infrastructure what you can hook into, fine. But I'm highly suspicious of using broken platforms as a justification for new infrastructure. --david