LISA auto/WW-GR2+WW-R+WW-R (* * Result: Sometimes * * Process 0 starts (t=197998). * * P0 advances one grace period (t=297998). * * P1 goes back a bit less than one grace period (t=198999). * * P2 goes back a bit less than one grace period (t=100000). * * Process 0 start at t=197998, process 3 end at t=100000: Cycle allowed. *) { } P0 | P1 | P2 ; w[once] x0 2 | f[rcu_read_lock] | f[rcu_read_lock] ; f[sync] | w[once] x1 2 | w[once] x2 2 ; f[rcu_read_lock] | w[once] x2 1 | w[once] x0 1 ; w[once] x1 1 | f[rcu_read_unlock] | f[rcu_read_unlock] ; f[rcu_read_unlock] | | ; Observed x2=2; x1=2; x0=2;