Messages in this thread |  | | | Subject | Re: [PATCH RFC tip/core/rcu] accelerate grace period if last non-dynticked CPU | | From | Peter Zijlstra <> | | Date | Wed, 27 Jan 2010 10:50:50 +0100 |
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On Wed, 2010-01-27 at 10:43 +0100, Andi Kleen wrote: > > Can't you simply check that at runtime then? > > if (num_possible_cpus() > 20) > ... > > BTW the new small is large. This years high end desktop PC will come with > upto 12 CPU threads. It would likely be challenging to find a good > number for 20 that holds up with the future.
If only scalability were that easy :/
These massive core/thread count things are causing more problems as well, the cpus/node ratios are constantly growing, giving grief in the page allocator as well as other places that used to scale per node.
As to the current problem, the call_rcu() interface doesn't make a hard promise that the callback will be done on the same cpu, right? So why not simply move the callback list over to a more active cpu?
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