Steven, In another kconfig (x86_64-allyesdebian), the "no entries found" will happen in about 1/10 boots. Mostly it's "irqsoff" not found, and can also be this "wakeup": [ 23.408441] Testing tracer wakeup: .. no entries found ..FAILED! [ 25.733327] ------------[ cut here ]------------ [ 25.734529] WARNING: at /c/kernel-tests/src/stable/kernel/trace/trace.c:834 register_tracer+0x19e/0x276() [ 25.737170] Hardware name: Bochs [ 25.738228] Modules linked in: [ 25.739383] Pid: 1, comm: swapper/0 Not tainted 3.5.0+ #1404 [ 25.740960] Call Trace: [ 25.742151] [] warn_slowpath_common+0x83/0x9c [ 25.745383] [] warn_slowpath_null+0x1a/0x1c [ 25.749132] [] register_tracer+0x19e/0x276 [ 25.751698] [] ? init_irqsoff_tracer+0x14/0x14 [ 25.755494] [] init_wakeup_tracer+0x10/0x22 [ 25.759205] [] do_one_initcall+0x7f/0x13a [ 25.762639] [] kernel_init+0x141/0x1c5 [ 25.765469] [] ? do_early_param+0x8c/0x8c [ 25.769294] [] kernel_thread_helper+0x4/0x10 [ 25.773081] [] ? retint_restore_args+0x13/0x13 [ 25.776405] [] ? start_kernel+0x3cf/0x3cf [ 25.780117] [] ? gs_change+0x13/0x13 Thanks, Fengguang