Florian Weimer <fw@deneb.enyo.de> writes:
> * Tom Lane:
>> On Linux (RHEL6, 2.4GHz x86_64), I find that gettimeofday(),
>> clock_gettime(CLOCK_MONOTONIC), and clock_gettime(CLOCK_REALTIME)
>> all take about 40ns. Of course gettimeofday() only has 1us resolution,
>> but the other two have perhaps 10ns resolution (I get no duplicate
>> readings in a tight loop).
> Isn't this very specific to kernel and glibc versions, depending on
> things like CONFIG_HZ settings and what level of vDSO support has been
> backported?
No doubt, but I have yet to find a platform where clock_gettime() exists
but performs worse than gettimeofday(). Do you know of one?
regards, tom lane