network statistics in SMP

Bruce Evans brde at
Thu Dec 17 08:28:12 UTC 2009

On Thu, 17 Dec 2009, Bruce Evans wrote:

> On Thu, 17 Dec 2009, Bruce Evans wrote:
>> ...
> Actually3, the generation count can be per-CPU and accessed without atomic
> ops (provided reads of it on other CPUs return a consistent possibly-stale
> value).
>> Simple version:
> Better version:
> ...

Duh, this is far too complicated and bloated.  Counters can be their own
generation counts -- you just read them again to see if they are quiescent.
A heavyweight sync before each of the (sets of) reads is still necessary.
Self-generation counters give a separate generation counter for each
normal counter, so quiescence can be easily be checked for and/or enforced 


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