Re: page fault scalability patch V11 [0/7]: overview

William Lee Irwin III
2004-11-20T03:43:49Z

William Lee Irwin III wrote:
>> Irrelevant. Unshare cachelines with hot mm-global ones, and the
>> "problem" goes away.

On Sat, Nov 20, 2004 at 02:14:33PM +1100, Nick Piggin wrote:
> That's the idea.

William Lee Irwin III wrote:
>> This stuff is going on and on about some purist "no atomic operations
>> anywhere" weirdness even though killing the last atomic operation
>> creates problems and doesn't improve performance.

On Sat, Nov 20, 2004 at 02:14:33PM +1100, Nick Piggin wrote:
> Huh? How is not wanting to impact single threaded performance being
> "purist weirdness"? Practical, I'd call it.

Empirically demonstrate the impact on single-threaded performance.

On Sat, Nov 20, 2004 at 01:40:40PM +1100, Nick Piggin wrote:
>> Why the Hell would you bother giving each cpu a separate cacheline?
>> The odds of bouncing significantly merely amongst the counters are not
>> particularly high.

On Sat, Nov 20, 2004 at 02:14:33PM +1100, Nick Piggin wrote:
> Hmm yeah I guess wouldn't put them all on different cachelines.
> As you can see though, Christoph ran into a wall at 8 CPUs, so
> having them densly packed still might not be enough.

Please be more specific about the result, and cite the Message-Id.

-- wli