Messages in this thread | | | Date | Thu, 26 Jun 2008 03:36:14 -0700 | From | Arjan van de Ven <> | Subject | Re: kmap_atomic_pfn for PCI BAR access? |
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On Thu, 26 Jun 2008 07:02:15 +0100 (IST) Dave Airlie <airlied@linux.ie> wrote:
> > > > > > > Anything that does any kind of pagetable manipulation needs to do > > tlb flushes. kunmap_atomic handles the flushing. > > It doesn't however need to do an IPI dance which is the worst part of > doing a tlb flush on SMP machines. > > flushing local CPU tlbs is bad, but doing IPIs and waiting for > everyone else is brutal.
but you only do IPI's for the multithreaded case to cpus where you're running; otoh I guess games are multithreaded nowadays
> > Dave.
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