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McKenney wrote: [...] >>>> AFAIU there is partial overlap between refcount, hazptr, and RCU, each >>>> with their own strengths and weaknesses. We should prepare a summary >>>> table for the end users wondering which is the right tool for their >>>> use-case. >>> >>> We have lots of such tables of varying sizes and levels of detail in >>> numerous C++ Working Papers, to say nothing of Section 9.6 of perfbook. ;-) >>> >>> One short text distinguishing them is: "RCU is a fast and scalable >>> replacement for many reader-writer locking use cases, hazard pointers is >>> a fast and scalable replacement for many reference-counting use cases, >>> reader-writer locking provides mutual exclusion, and reference counting >>> provides instant notice when the counter reaches zero." >> >> lgtm > > Fair enough! Put this in Documentation/RCU? As a header comment in > include/linux/hazptr.h? Somewhere else? > I'm tempted to add the documentation into Documentation/RCU and a reference to it in the RCU, hazptr, and refcount headers so people stumbling on one of those three can be pointed to the higher level document which explains how each relate to one another. But is referencing documentation from code even something we typically do ? Also given this would discuss more than just RCU, I'm not sure Doc/RCU is the right home for it, but we don't have a Documentation/existence nor Documentation/synchronization. Thoughts ? Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. https://www.efficios.com