On Tue, Feb 12, 2008 at 10:11:13AM -0800, Linus Torvalds wrote: > > > On Tue, 12 Feb 2008, Andi Kleen wrote: > > > > > - the kgdb commands should always act on the *current* CPU only > > > - add one command that says "switch over to CPU #n" which just releases > > > the current CPU and sends an IPI to that CPU #n (no timeouts, no > > > synchronous waiting, no nothing - it's like a "continue", but with a > > > "try to get the other CPU to stop" > > > > The problem I see here is that the kernel tends to get badly confused > > if one CPU just stops responding. At some point someone does an global > > IPI and that then hangs. You would need to hotunplug the CPU which > > is theoretically possible, but quite intrusive. > > You're thinking about this totally *wrong*. > > You definitely do not want to hot-unplug or isolate anything at all.
I agree that it wouldn't be a good idea -- i was just pointing out consequences of your proposal. > Just let the other CPU's hang naturally if they need to wait for IPI's > etc. What's the downside? There tend to be timeouts (e.g. softlock/nmi watchdog at least). I think some of the IPIs eventually time out too. In general losing a lot of time can lead to weird side effects. -Andi -- 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/
