LISA auto/RW-G+RW-Rr+RW-RC+RW-G+RW-R (* * Result: Never * * Process 0 starts (t=100000). * * P0 advances one grace period (t=200000). * * P1 advances slightly (t=200002). * * P2 advances slightly (t=200004). * * P3 advances one grace period (t=300005). * * P4 goes back a bit less than one grace period (t=201006). * * Process 0 start at t=100000, process 5 end at t=201006: Cycle forbidden. *) { } P0 | P1 | P2 | P3 | P4 ; r[once] r1 x0 | f[rcu_read_lock] | f[rcu_read_lock] | r[once] r1 x3 | f[rcu_read_lock] ; f[sync] | r[once] r1 x1 | r[once] r1 x2 | f[sync] | r[once] r1 x4 ; w[once] x1 1 | w[release] x2 1 | mov r4 (eq r1 r4) | w[once] x4 1 | w[once] x0 1 ; | f[rcu_read_unlock] | b[] r4 CTRL2 | | f[rcu_read_unlock] ; | | w[once] x3 1 | | ; | | CTRL2: | | ; | | f[rcu_read_unlock] | | ; Observed 4:r1=0; 3:r1=1; 2:r1=1; 1:r1=1; 0:r1=1; and 4:r1=1; 3:r1=0; 2:r1=1; 1:r1=1; 0:r1=1; and 4:r1=0; 3:r1=0; 2:r1=1; 1:r1=1; 0:r1=1; and 4:r1=1; 3:r1=0; 2:r1=0; 1:r1=1; 0:r1=1; and 4:r1=1; 3:r1=0; 2:r1=1; 1:r1=0; 0:r1=1; and 4:r1=1; 3:r1=1; 2:r1=1; 1:r1=1; 0:r1=0; and 4:r1=0; 3:r1=1; 2:r1=1; 1:r1=1; 0:r1=0; and 4:r1=1; 3:r1=0; 2:r1=1; 1:r1=1; 0:r1=0; and 4:r1=0; 3:r1=0; 2:r1=1; 1:r1=1; 0:r1=0; and 4:r1=1; 3:r1=0; 2:r1=0; 1:r1=1; 0:r1=0; and 4:r1=0; 3:r1=0; 2:r1=0; 1:r1=1; 0:r1=0;