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Seperate from mm::mm_users Separate > + * as that is modified by mmget()/mm_put() by other entities which > + * do not actually share the MM. > * @lock: Spinlock to protect all fields except @pcpu. It also protects > * the MM cid cpumask and the MM cidmask bitmap. > */ > struct mm_mm_cid { > struct mm_cid_pcpu __percpu *pcpu; > + unsigned int max_cids; > unsigned int nr_cpus_allowed; > + unsigned int users; I suspect this reintroduces false-sharing between the "users" and "lock" fields (updated every time a thread is forked/exits) and load of the pcpu pointer which is pretty much immutable. This will slow down accesses to the percpu data in the scheduler fast path. > raw_spinlock_t lock; > }____cacheline_aligned_in_smp; > #else /* CONFIG_SCHED_MM_CID */ Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. https://www.efficios.com