Hi Armin,

On Tue, Apr 26, 2016 at 10:56 AM, Armin Rigo <arigo@tunes.org> wrote:

Hi,

On 25 April 2016 at 08:25, Maciej Fijalkowski <fijall@gmail.com> wrote:

...

The problem with disabled ASLR is that you change the measurment from a statistical distribution, to one draw from a statistical distribution repeatedly. There is no going around doing multiple runs and doing an average on that.

You should mention that it is usually enough to do the following: instead of running once with PYTHONHASHSEED=0, run five or ten times with PYTHONHASHSEED in range(5 or 10). In this way, you get all benefits: not-too-long benchmarking, no randomness, but still some statistically relevant sampling.

​note that here there are two sources of "randomness": one is PYTHONHASHSEED (which you can control with the env variable), the other is ASLR​ which, AFAIK, you cannot control in the same fine way: you can only either enable or disable it.