From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jesse Barnes Date: Tue, 04 May 2004 22:36:13 +0000 Subject: Re: [RFC] I/O MCA recovery Message-Id: <200405041536.13104.jbarnes@engr.sgi.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 Tuesday, May 4, 2004 11:20 am, David Mosberger wrote: > 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. Wouldn't that mean that on every I/O access we'd have to page fault, do the I/O, and then invalidate the mapping? That seems like a lot of overhead. > 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. Are you describing ia64 as a broken platform here? The problem I'm trying to solve isn't sn2 specific (though part of the X stuff I have to do will be driven by sn2 requirements), it's a generic way to deal with hard fails on PIO reads, which afaik, affects all ia64 platforms. Correct me if I'm wrong here... Thanks, Jesse