What were you trying to do that didn't work?

When having a high nofile limit, lsof spends its time closing non-existent file descriptors before proceeding. The operation can take several minutes and consumes a single CPU entirely, generating unnecessary load.

This got fixed Upstream through following commit:

commit b953ba3b1a93fc44771b900ff519931e3380aa82
Author: Marc <34656315+MarcT512@users.noreply.github.com>
Date:   Wed May 15 11:33:23 2024 +0100

    Add files via upload
    
    Add an optimized fallback in closefrom_shim() for Linux, if the platform doesn't support closefrom or close_range.
    Iterate /proc/self/fd and close anything which is not that directory itself.

What is the impact of this issue to you?

Cannot execute lsof in a timely manner

Please provide the package NVR for which the bug is seen:

lsof-4.94.0-3

How reproducible is this bug?:

Always

Steps to reproduce

1. Execute lsof after changing the nofile limit

   # ulimit -n 1073741816
   # lsof
   

Expected results

Almost immediate return.

Actual results

100% CPU consumed for several minutes.