Messages in this thread |  | | Date | Mon, 30 Nov 2020 09:57:52 -0500 (EST) | From | Mathieu Desnoyers <> | Subject | Re: [PATCH 2/8] x86: use exit_lazy_tlb rather than membarrier_mm_sync_core_before_usermode |
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----- On Nov 28, 2020, at 11:01 AM, Nicholas Piggin npiggin@gmail.com wrote:
> And get rid of the generic sync_core_before_usermode facility. This is > functionally a no-op in the core scheduler code, but it also catches
This sentence is incomplete.
> > This helper is the wrong way around I think. The idea that membarrier > state requires a core sync before returning to user is the easy one > that does not need hiding behind membarrier calls. The gap in core > synchronization due to x86's sysret/sysexit and lazy tlb mode, is the > tricky detail that is better put in x86 lazy tlb code.
Ideally yes this complexity should sit within the x86 architecture code if only that architecture requires it.
Thanks,
Mathieu
-- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com
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