hi all: I grep kernel source and found cpu_relax is defined as __memory_barrier(), which seems not defined in kernel source. At beginning I think it may be the gcc build-in functions, but I cannot find in the gcc document. Where and what is that used for? -- Regards, miloody _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies