On Mon, Aug 12, 2024 at 11:22 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote: > > Oh yeah, duh, re-read after PAUSE, not before. > > Definitely holler if you have any alternative ideas for walking rmaps > without taking mmu_lock, I guarantee you've spent more time than me > thinking about the shadow MMU :-) We use the same bit and the same way for the rmap lock. We just use bit_spin_lock() and the optimization for empty rmap_head is handled out of kvm_rmap_lock(). bit_spin_lock() has the most-needed preempt_disable(). I'm not sure if the new kvm_rmap_age_gfn_range_lockless() is called in a preempt disabled region. Thanks Lai
