PowerTOP crashes on ppc64 machine with 1 idle state, reproducer: # powertop -t 1 --html Parameters of the machine are attached. It seems the problem is caused by the report_display_cpu_cstates() function from the src/cpu/cpu.cpp file. On https://github.com/fenrus75/powertop/blob/e8765b5475b22b7a2b6e9e8a031c68a... it allocates table 2x1, but the table should be 2x2 (header + 1 state), so it later crashes on https://github.com/fenrus75/powertop/blob/e8765b5475b22b7a2b6e9e8a031c68a... where it tries to fill the table. Unfortunately, the whole reporting code is quite unclear, so I am not sure how to correctly fix it and not break anything else. The attached patch fixes the problem for me, but it can have side-effects - feel free to propose better fix thanks & regards Jaroslav Machine parameters: # cpupower idle-info CPUidle driver: pseries_idle CPUidle governor: menu analyzing CPU 0: Number of idle states: 1 Available idle states: Shared Cede Shared Cede: Flags/Description: Shared Cede Latency: 0 Usage: 1188350 Duration: 14152220333 # cat /proc/cpuinfo processor : 0 cpu : POWER8E (raw), altivec supported clock : 3425.000000MHz revision : 2.1 (pvr 004b 0201) processor : 1 cpu : POWER8E (raw), altivec supported clock : 3425.000000MHz revision : 2.1 (pvr 004b 0201) processor : 2 cpu : POWER8E (raw), altivec supported clock : 3425.000000MHz revision : 2.1 (pvr 004b 0201) processor : 3 cpu : POWER8E (raw), altivec supported clock : 3425.000000MHz revision : 2.1 (pvr 004b 0201) processor : 4 cpu : POWER8E (raw), altivec supported clock : 3425.000000MHz revision : 2.1 (pvr 004b 0201) processor : 5 cpu : POWER8E (raw), altivec supported clock : 3425.000000MHz revision : 2.1 (pvr 004b 0201) processor : 6 cpu : POWER8E (raw), altivec supported clock : 3425.000000MHz revision : 2.1 (pvr 004b 0201) processor : 7 cpu : POWER8E (raw), altivec supported clock : 3425.000000MHz revision : 2.1 (pvr 004b 0201) timebase : 512000000 platform : pSeries model : IBM pSeries (emulated by qemu) machine : CHRP IBM pSeries (emulated by qemu)