Re: [PATCH 00/10] perf/uprobe: Optimize uprobes

[Peter Zijlstra]

On Mon, Jul 08, 2024 at 05:25:14PM -0700, Andrii Nakryiko wrote:

> Quick profiling for the 8-threaded benchmark shows that we spend >20%
> in mmap_read_lock/mmap_read_unlock in find_active_uprobe. I think
> that's what would prevent uprobes from scaling linearly. If you have
> some good ideas on how to get rid of that, I think it would be
> extremely beneficial. 

That's find_vma() and friends. I started RCU-ifying that a *long* time
ago when I started the speculative page fault patches. I sorta lost
track of that effort, Willy where are we with that?

Specifically, how feasible would it be to get a simple RCU based
find_vma() version sorted these days?