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McKenney wrote: [...] >> This is effectively a use of split-counters, but the split >> is across concurrency handling mechanisms rather than across >> CPUs. > > Ah, got it, thank you! But we would need an additional softirq counter, > correct? Fundamentally it depends on how you want to split frequent vs infrequent accesses. If the fast-paths you care about are all in thread context, then you only need to split between percpu ops vs atomic counters. The per-thread accesses would use percpu ops, and all the rest use atomics. The "all the rest" can cover everything else including softirqs, irq, and nmis. > > I will keep this in my back pocket in case Catalin's and Yicong's prefetch > trick turns out to be problematic, and again, thank you! You're welcome! :) Mathieu -- Mathieu Desnoyers EfficiOS Inc. https://www.efficios.com