C auto/C-WW-R+WW-R+WW-R+WW-R+WW-R+WW-R (* * Result: Sometimes * * Process 0 starts (t=693995). * * P0 goes back a bit less than one grace period (t=594995). * * P1 goes back a bit less than one grace period (t=495996). * * P2 goes back a bit less than one grace period (t=396997). * * P3 goes back a bit less than one grace period (t=297998). * * P4 goes back a bit less than one grace period (t=198999). * * P5 goes back a bit less than one grace period (t=100000). * * Process 0 start at t=693995, process 6 end at t=100000: Cycle allowed. *) { } P0(int *x0, int *x1) { rcu_read_lock(); WRITE_ONCE(*x0, 2); WRITE_ONCE(*x1, 1); rcu_read_unlock(); } P1(int *x1, int *x2) { rcu_read_lock(); WRITE_ONCE(*x1, 2); WRITE_ONCE(*x2, 1); rcu_read_unlock(); } P2(int *x2, int *x3) { rcu_read_lock(); WRITE_ONCE(*x2, 2); WRITE_ONCE(*x3, 1); rcu_read_unlock(); } P3(int *x3, int *x4) { rcu_read_lock(); WRITE_ONCE(*x3, 2); WRITE_ONCE(*x4, 1); rcu_read_unlock(); } P4(int *x4, int *x5) { rcu_read_lock(); WRITE_ONCE(*x4, 2); WRITE_ONCE(*x5, 1); rcu_read_unlock(); } P5(int *x0, int *x5) { rcu_read_lock(); WRITE_ONCE(*x5, 2); WRITE_ONCE(*x0, 1); rcu_read_unlock(); } Observed x5=2; x4=2; x3=2; x2=2; x1=2; x0=2;