Messages in this thread | | | Date | Thu, 9 Nov 2017 18:30:27 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v4] lib/dlock-list: Scale dlock_lists_empty() |
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On Thu, Nov 09, 2017 at 09:24:08AM -0800, Davidlohr Bueso wrote: > On Wed, 08 Nov 2017, Boqun Feng wrote: > > Or worse: > > > > * CPU0 CPU1 > > * dlock_list_add() dlock_lists_empty() > > * smp_mb__before_atomic(); > > * [L] atomic_read(used_lists)
Note that this is broken; smp_mb__before_atomic() is not valid on atomic_read().
> > * [S] atomic_inc(used_lists); > > * smp_mb__after_atomic(); > >
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