Hi, Some of the things we do here at Intel, in our Languages Performance Lab [1,2], is to disable ASLR as you get more reliable results. This can be achieved on Linux by running echo 0 > /proc/sys/kernel/randomize_va_space. Also, setting the CPU frequency at a fixed frequency, disabling Turbo Boost and Hyper Threading, also helps for benchmark stability.
>From my experience, the isolcpus feature is useful when you have a lot of >cores on your machine because the kernel will have other cores on which it can >schedule its work; furthermore, it is a best effort situation and it is not an >absolute guarantee that the kernel will not use the cores specified if you >have a lot of processes running (for example, if you benchmark on a machine >with 2 physical cores and you isolate one of the cores, there is a big chance >that the kernel will schedule processes on this core also, even it is for a >small amount of time). Nevertheless, for machines with more physical cores, it >can be good to have dedicated core(s) on which we do benchmarking. [1] http://languagesperformance.intel.com/ [2] https://lists.01.org/pipermail/langperf/ Thank you, Alecsandru > -----Original Message----- > From: Speed [mailto:speed- > bounces+alecsandru.patrascu=intel....@python.org] On Behalf Of Victor > Stinner > Sent: Friday, February 12, 2016 12:54 AM > To: speed@python.org > Subject: [Speed] Linux tip: use isolcpus to have (more) reliable benchmark > > Hi, > > I'm sharing with you my notes (tricks) to get more reliable benchmarks on > Linux if your CPU have multiple cores: > > https://haypo-notes.readthedocs.org/microbenchmark.html#reliable-micro- > benchmarks > > FYI perf.py recently got a new --affinity= optional parameter. I plan to > send a patch to automatically use /sys/devices/system/cpu/isolated if it's > not empty. > > What are your "tricks" to get reliable benchmarks? > > Victor > _______________________________________________ > Speed mailing list > Speed@python.org > https://mail.python.org/mailman/listinfo/speed _______________________________________________ Speed mailing list Speed@python.org https://mail.python.org/mailman/listinfo/speed
