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Assuming that we can make it only issue= d for=0A= > LD_DEBUG=3Dstatistics (I need to check if they are used outside it), it w= ill be=0A= > basically the cost of calling clock_gettime on the architecture without t= he=0A= > support.=0A= =0A= I checked and found an old server that traps. The emulation is surprisingly= fast -=0A= only a factor of 10 overhead. On several cores using cntvct_el0 is twice as= fast=0A= as clock_gettime. This remains true even if trapped (ie. vDSO is disabled).= =0A= =0A= That means there is no issue with using cntvct_el0 in hp_timing.h since it = doesn't=0A= crash and is never slower. So we could just add the header without needing= =0A= kernel fixes.=0A= =0A= Cheers,=0A= Wilco=