Re: x86: Is there still value in having a special tlb flush IPIvector?

From: Ingo Molnar
Date: Thu Jul 31 2008 - 16:57:58 EST



* Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:

> Peter Zijlstra wrote:
> > How about using just arch_send_call_function_single_ipi() to implement
> > smp_send_reschedule() ?
> >
> > The overhead of that is a smp_mb() and a list_empty() check in
> > generic_smp_call_function_single_interrupt() if there is indeed no work
> > to do.
>
> Is doing a no-op interrupt sufficient on all architectures? Is there
> some change a function call IPI might not go through the normal
> reschedule interrupt exit path?

We'd still use the smp_send_reschdule(cpu) API, so it's an architecture
detail. On x86 we'd use arch_send_call_function_single_ipi().

Ingo
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