Messages in this thread |  | | | Date | Mon, 4 Feb 2008 11:30:01 +0100 | | From | Andi Kleen <> | | Subject | Re: [rfc] direct IO submission and completion scalability issues |
> + q = &__get_cpu_var(call_single_queue);
> + spin_lock_irqsave(&q->lock, flags);
> + list_replace_init(&q->list, &list);
> + spin_unlock_irqrestore(&q->lock, flags);
I think you could do that lockless if you use a similar data structure
as netchannels (essentially a fixed size single buffer queue with atomic
exchange of the first/last pointers) and not using a list. That would avoid
at least one bounce for the lock and likely another one for the list
manipulation.
Also the right way would be to not add a second mechanism for this,
but fix the standard smp_call_function_single() to support it.
-Andi
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