Messages in this thread | | | Date | Tue, 9 Sep 2008 07:54:53 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH] prevent sparc64 from invoking irq handlers on offline CPUs |
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On Mon, Sep 08, 2008 at 05:17:08PM -0700, David Miller wrote: > From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> > Date: Wed, 3 Sep 2008 08:42:17 -0700 > > o Timer irqs. Not sure what happens to add_timer() calls from > > a CPU that is going offline. The hope would be that they get > > queued to some other CPU? > > This case is interesting, and I'm no sure what happens here.
It turns out that there is a timer_cpu_modifier() that invokes migrate_timers() upon CPU_DEAD or CPU_DEAD_FROZEN. And migrate_timers() looks like it does what its name says. And I believe that CPU_DEAD happens after sparc64's local_irq_enable() window, so we should be OK.
Thanx, Paul
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