Messages in this thread | | | Date | Tue, 11 Jul 2017 08:09:16 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [GIT pull] smp/hotplug updates for 4.13 |
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On Sun, 9 Jul 2017, Linus Torvalds wrote: > On Sun, Jul 9, 2017 at 2:07 AM, Thomas Gleixner <tglx@linutronix.de> wrote: > > > > + /* Wait for the CPU to reach CPUHP_AP_ONLINE_IDLE */ > > wait_for_completion(&st->done); > > + BUG_ON(!cpu_online(cpu)); > > I realize this isn't actually a new BUG_ON(), just a moved one, but > can we *please* just agree to get rid of these machine-killing > idiocies? > > The fact that it would be a bug if this triggers doesn't excuse it one > whit. BUG_ON() is simply bad. > > Either it's a "this cannot happen", in which case it should be > deleted, or it's a "if this ever happens, we really should notice it", > in which case it should probably be a > > if (WARN_ON)ONCE(..)) > return -EBUSY; > > or something. > > That routine very much has an existing error path for failure to bring > up a CPU, dammit! > > THERE IS NO EXCUSE FOR KILLING THE MACHINE THERE!
Agreed. I noticed when I moved the code, but then forgot. Will queue a fix.
Thanks,
tglx
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