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>> + /* >> + * Order the store against the subsequent fixups so that >> + * acquire(rq::lock) cannot be reordered by the CPU before the >> + * store. >> + */ >> + smp_mb(); >> return true; >> } >> >> @@ -10487,6 +10493,16 @@ static inline void mm_update_cpus_allowe >> irq_work_queue(&mc->irq_work); >> } >> >> +static inline void mm_cid_complete_transit(struct mm_struct *mm, unsigned int mode) >> +{ >> + /* >> + * Ensure that the store removing the TRANSIT bit cannot be >> + * reordered by the CPU before the fixups have been completed. >> + */ >> + smp_mb(); >> + WRITE_ONCE(mm->mm_cid.mode, mode); >> +} > > I think this could've been smp_store_release(), but this is the slow > path so nobody cares and this is nicely symmetric. I'm not sure the store-release would work here. What load-acquire would it pair with ? Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. https://www.efficios.com