Add --taskset to bench_runtime_local

[fmayer]

This allows to run a benchmark on a subset of CPUs

[Kobzol]

Hi, can't you just apply taskset to the whole collector invocation? 🤔

[fmayer]

Hi, can't you just apply taskset to the whole collector invocation? 🤔

That will make the build quite a lot slower..

[Kobzol]

You can build it once without taskset using --no-isolate, and then run it for the second time with taskset, which will not rebuild the things again.

In general, adding one-off things like this, especially if we don't make use of them, is a bit of a maintenance no-no from me. That being said, I'd be fine with a more general mechanism, e.g. something like --cmd-prefix "taskset -c 1", which would allow users to pass any command that would then be prepended before the executed benchmark. We'd have to either naively split it by spaces or shlex parse it, but that shouldn't be such an issue. Maybe even clap can pre-parse it for us.

[fmayer]

Sure, sorry for the noise then.

[Kobzol]

I'll add the generic command prefix to my TODO list and let you know if it lands.