Re: [PATCH]broadcast IPI race condition on CPU hotplug

From: Zwane Mwaikambo
Date: Mon Apr 25 2005 - 23:47:06 EST

On Tue, 26 Apr 2005, Li Shaohua wrote:

> On Tue, 2005-04-26 at 12:25, Zwane Mwaikambo wrote:
> >
> > > After a CPU is booted but before it's officially up (set online map, and
> > > enable interrupt), the CPU possibly will receive a broadcast IPI. After
> > > it's up, it will handle the stale interrupt soon and maybe cause oops if
> > > it's a smp-call-function-interrupt. This is quite possible in CPU
> > > hotplug case, but nearly can't occur at boot time. Below patch replaces
> > > broadcast IPI with send_ipi_mask just like the cluster mode.
> >
> > Ok, but isn't it sufficient to use send_ipi_mask in smp_call_function
> > instead?
> I'm not sure if other routines using broadcast IPI have this bug. Fixing
> the send_ipi_all API looks more generic. Is there any reason we should
> use broadcast IPI?

I'd prefer only touching smp_call_function because the others are
primitives, we should only be fixing the users of the primitives,
otherwise we'll end up with code which won't be as versatile.

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at