LISA 2+2w+o-mb-o+o-wb-o (* * Allow per Linus Torvalds email: * http://www.spinics.net/lists/arm-kernel/msg483690.html *) { x = 0; y = 0; } P0 | P1 ; w[once] x 1 | w[once] y 1 ; f[mb] | f[wmb] ; w[once] y 2 | w[once] x 2 ; Observed y=1; x=1;