Re: [PATCH] tests: switch nap() to use file creation to gauge delay

[Bruno Haible]

Hi Jeff,

You wrote on 2024-06-28:
> There are some proposed changes [1] to track finer-grained timestamps in
> the Linux kernel that will break the assumptions that nap() uses to
> gauge the delay. In particular, writing to a file will almost always
> show a change in the timestamp now, so usually this method will settle
> on a delay of 1ns.
> ...
> test-stat-time still fails without this change.

The paperwork being complete now, I wanted to verify that the patch
indeed fixes the problem. But I can't reproduce the problem in the first
place.

Here's what I did:
  - Install Fedora Rawhide (Linux 
6.11.0-0.rc0.20240719git720261cfc732.7.fc41.x86_64).
  - Create a testdir
    $ ./gnulib-tool --create-testdir --dir=../testdir1 --single-configure chown 
fchownat fdutimensat futimens lchown stat-time utime utimens utimensat
  - Build it, both on an ext4 file system and a btrfs file system.
  => No test failure is seen.

What am I missing? What do I need to change in my setup, in order to
reproduce the problem?

Bruno