From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russ Anderson Date: Sun, 20 Jul 2008 17:50:04 +0000 Subject: Re: [PATCH 0/2] Migrate data off physical pages with corrected memory errors (Version 7) Message-Id: <20080720175004.GB9409@sgi.com> List-Id: References: <20080718203514.GD29621@sgi.com> <87prpa88iw.fsf@basil.nowhere.org> <20080719121328.GA20138@parisc-linux.org> In-Reply-To: <20080719121328.GA20138@parisc-linux.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Matthew Wilcox Cc: Andi Kleen , mingo@elte.hu, tglx@linutronix.de, Tony Luck , linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org On Sat, Jul 19, 2008 at 06:13:28AM -0600, Matthew Wilcox wrote: > On Sat, Jul 19, 2008 at 12:37:11PM +0200, Andi Kleen wrote: > > Russ Anderson writes: > > > > > [PATCH 0/2] Migrate data off physical pages with corrected memory errors (Version 7) > > > > FWIW I discussed this with some hardware people and the general > > opinion was that it was way too aggressive to disable a page on the > > first corrected error like this patchkit currently does. > > I think it's reasonable to take a page out of service on the first error. > Then a user program needs to be notified of which bit is suspected. > It can then subject that page to an intense set of tests (I'd start > by stealing the ones from memtest86+) and if no more errors are found, > it could return the page to service. In general I agree with that approach. One concern is that in the process of testing the memory the diagnostic may hit an uncorrectable error. That is not a problem with Itanium, which is designed to handle uncorrected/poisoned data going into and out of the processor core, but can be a system fatal error (requiring a reboot) on other processor types. Just something to be aware of. -- Russ Anderson, OS RAS/Partitioning Project Lead SGI - Silicon Graphics Inc rja@sgi.com