This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


Re: [Xen-devel] crashes

On Jul 31, 2004, at 7:48 AM, Ian Pratt wrote:

The "Failed MMU update" messages are very interesting, and I've
never seen them before -- xen is refusing to transfer the page to
dom1 for some reason. Please can you try doing the same with a
debug=y build of Xen. Xen should tell us a bit more about why
it's refusing the request.

I've gotten several "Failed MMU update" messages, with debug=y compiled Xen kernels and all debugging options enabled in the kernel. Unfortunately, there wasn't a whole lot else output in any of the cases where I would see "Failed MMU update" and then a crash. I haven't had a chance to really touch Xen for a little over a week now, and I'd seen it for at least a week or so before that, so I'm reasonably certain none of the recent block changes were in any of the code that output the MMU errors.

I can't find the specific messages now (I'm at work, and in a meeting too. oh, but I'm paying attention to the meeting ... ;) but one of the last couple of posts I've made to the list included a ton of the debug output from Xen during the MMU crash. The only thing I saw unusual was some sort of "protection fault" or something on the Xen console a few minutes before the MMU error/crash popped up.

Also, almost always, the "failed MMU update" happens at the very end of a crash, just before the system reboots. i.e. the system becomes unstable and I reboot or it crashes and reboots itself, and the last message on the console before the reboot is usually the "failed MMU update" message.

"I think that's what they mean by   |
"nickels a day can feed a child."   |       http://www.eff.org/
I thought, "How can food be so      | http://www.anti-dmca.org/
cheap over there?"  It's not, they  |--------------------------
just eat the nickels." -- Peter Nguyen

"We all enter this world in the    | Support Electronic Freedom
same way: naked; screaming; soaked |        http://www.eff.org/
in blood. But if you live your     |  http://www.anti-dmca.org/
life right, that kind of thing     |---------------------------
doesn't have to stop there." -- Dana Gould

This SF.Net email is sponsored by OSTG. Have you noticed the changes on
Linux.com, ITManagersJournal and NewsForge in the past few weeks? Now,
one more big change to announce. We are now OSTG- Open Source Technology
Group. Come see the changes on the new OSTG site. www.ostg.com
Xen-devel mailing list

<Prev in Thread] Current Thread [Next in Thread>