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.
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