Hyper-threading - By which test can I check if it is enabled or disabled?

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http://stackoverflow.com – Is there any simple performance test to detect is HT enabled or not? For example I need it it case when max CPU number is limited by linux kernel(NR_CPUS) and no access to BIOS. So could you advice any code to detect is HT enabled? I glanced here or here but it's not the answers. Thanx. (HowTos)