Re: noatime mounts inhibiting atime updates via utime()

[Piotr Meyer <aniou%smutek.pl@localhost>]

On Tue, Dec 04, 2018 at 08:23:20PM -0800, Jason Thorpe wrote:
[...]

> Honestly, I think atime is one of the dumbest thing ever.  But if one
> must support it, then I think the following is a reasonable
> compromise:
> 
> -- If one is asked explicitly to set the atime by the user, then by
> all means, go for it.
> 
> -- Implicit atime updates made by the file system should NEVER trigger
> an I/O, but merely update the in-memory copy of the inode.  If, for
> some reason, that inode is pushed out to disk for some other reason,
> then by all means allow the atime field to be updated at the same
> time.

It looks like a behaviour similar to "lazytime", recently introduced 
in Linux, after some years of experiments like "relatime".

A short list of currently known behaviours (in different OS-es):
https://en.wikipedia.org/wiki/Stat_(system_call)#Criticism_of_atime

Regards,
-- 
Piotr 'aniou' Meyer