On Mon, 21 Oct 2019, Huacai Chen wrote: > @@ -50,7 +50,7 @@ static int do_hres(const struct vdso_data *vd, clockid_t clk, > cycles = __arch_get_hw_counter(vd->clock_mode); > ns = vdso_ts->nsec; > last = vd->cycle_last; > - if (unlikely((s64)cycles < 0)) > + if (unlikely(cycles == U64_MAX)) > return -1; That used to create worse code than the weird (s64) type cast which has the same effect. Did you double check that there is no change? Thanks, tglx