On Fri, 02 Feb 2007 18:39:15 -0700 [EMAIL PROTECTED] (Eric W. Biederman) wrote:
> Andrew Morton <[EMAIL PROTECTED]> writes: > > > So is this a for-2.6.20 thing? The bug was present in 2.6.19, so > > I assume it doesn't affect many people? > > If it's not to late, and this patch isn't too scary. > > It's a really rare set of circumstances that trigger it, but the > possibility of being hit is pretty widespread, anything with > more than one cpu, and more then one irq could see this. > > The easiest way to trigger this is to have two level triggered irqs on > two different cpus using the same vector. In that case if one acks > it's irq while the other irq is migrating to a different cpu 2.6.19 > get completely confused and stop handling interrupts properly. > > With my previous bug fix (not to drop the ack when we are confused) > the machine will stay up, and that is obviously correct and can't > affect anything else so is probably a candidate for the stable tree. > > With this fix everything just works. > > I don't know how often a legitimate case of the exact same irq > going off twice in a row is, but that is a possibility as well > especially with edge triggered interrupts. > > Setting up the test scenario was a pain, but by extremely limiting > my choice of vectors I was able to confirm I survived several hundred > of these events with in a couple of minutes no problem. > OK, thanks. Let's await Andi's feedback. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/