Re: [PATCH 1/2] pidmap(2)

[Andrew Morton]

On Tue, 5 Sep 2017 22:05:00 +0300 Alexey Dobriyan <adobriyan@xxxxxxxxx> wrote:

> Implement system call for bulk retrieveing of pids in binary form.
> 
> Using /proc is slower than necessary: 3 syscalls + another 3 for each thread +
> converting with atoi().
> 
> /proc may be not mounted especially in containers. Natural extension of
> hidepid=2 efforts is to not mount /proc at all.
> 
> It could be used by programs like ps, top or CRIU. Speed increase will
> become more drastic once combined with bulk retrieval of process statistics.

The patches are performance optimizations, but their changelogs contain
no performance measurements!

Demonstration of some compelling real-world performance benefits would
help things along a lot.