* Don Zickus <dzickus@xxxxxxxxxx> wrote: > On Mon, Aug 18, 2014 at 11:16:44AM +0200, Ingo Molnar wrote: > > > > * Don Zickus <dzickus@xxxxxxxxxx> wrote: > > > > > The running kernel still has the ability to enable/disable at any > > > time with /proc/sys/kernel/nmi_watchdog us usual. However even > > > when the default has been overridden /proc/sys/kernel/nmi_watchdog > > > will initially show '1'. To truly turn it on one must disable/enable > > > it, i.e. > > > echo 0 > /proc/sys/kernel/nmi_watchdog > > > echo 1 > /proc/sys/kernel/nmi_watchdog > > > > This looks like a bug, why is this so? > > It is, but it always has been there in the case of the PMU > not being able to provide a resource for the hardlockup. > This change just exposes it more. There seems to be two issues: 1) When it's impossible to enable the hardlockup detector, it should default to -1 or so, and attempts to set it should return a -EINVAL or so. Bootup messages should also indicate when it's not possible to enable it but a user requests it. 2) The softlockup and hardlockup detection control variables should be in separate flags, inside and outside the kernel - they (should) not relate to each other. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
