toplev --show-sample adds unnecessary perf -o parameter

[turol]

Using toplev's --show-sample parameter generates a perf command with an unnecessary -o perf.data.n parameter where n is some number. It seems to be related to the used level. This makes it harder to use the generated command since it has to be edited out instead of just copy-pasting the whole command.

[andikleen]

On Thu, Sep 15, 2022 at 08:14:35AM -0700, Turo Lamminen wrote:

Using toplev's --show-sample parameter generates a perf command with an unnecessary -o perf.data.n parameter where n is some number. It seems to be related to the used level. This makes it harder to use the generated command since it has to be edited out instead of just copy-pasting the whole command.

Do you have a command line? It should only add the number if it could collect multiple runs, which requires different output files.

[turol]

Command and slightly redacted output: https://gist.github.com/turol/f768fa7efb10f1e2215cfaf4b944eb56

[andikleen]

You are using --drilldown, so it shows the sample steps multiple times for each drill down step and each needs an unique file name.

Maybe it could only show it for the last one, and not do that but that would be different semantics.

[turol]

I think that whatever toplev needs to do internally should have no effect on the command shown to the user. The command shown should be one that is simple to copy and execute.