Messages in this thread | | | From | Linus Torvalds <> | Date | Wed, 28 Jul 2021 11:32:00 -0700 | Subject | Re: [PATCH v2 rcu 04/18] rcu: Weaken ->dynticks accesses and updates |
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On Wed, Jul 28, 2021 at 11:12 AM Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote: > > Are the percpu atomics you have in mind different from what is found in > Documentation/core-api/this_cpu_ops.rst ? > > Namely this_cpu_add_return(pcp, val) in this case.
Nope.
Those are only "CPU-atomic", ie atomic wrt interrupts etc.
The RCU code wants SMP-atomic, and it's mainly that we *could* do the addressing more efficiently.
Linus
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