Messages in this thread | | | Date | Thu, 10 Jan 2008 11:07:12 +0100 | From | Andi Kleen <> | Subject | Re: CPA patchset |
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On Thu, Jan 10, 2008 at 11:04:43AM +0100, Ingo Molnar wrote: > > * Andi Kleen <ak@suse.de> wrote: > > > > WBINVD isnt particular fast (takes a few msecs), but why is that a > > > problem? Drivers dont do high-frequency ioremap-ing. It's > > > typically only done at driver/device startup and that's it. > > > > Actually graphics drivers can do higher frequency allocation of WC > > memory (with PAT) support. > > but that's not too smart: why dont they use WB plus cflush instead?
Because they need to access it WC for performance.
> ioremap() will always be slow and we dont care about stupid uses of it.
Uninterruptible msec latencies are too slow even for slow path initialization code imho.
-Andi
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