cb877d0050
the inter-value histogram for 2000 samples. If the width is 3 or less for 10 consequtive samples, we trust the counter to be good, otherwise we use the *_safe() method. This method may be too strict, but the worst which can happen is that we take the performance hit of the *_safe() method when we should not. Make the *_safe() method more discriminating by mandating that the three samples do not span more than 15 ticks on the counter. Disable the PCI-ident based probing as a means to recognize good counters. Inspiration from: dillon and msmith