> > > Because peoples don't look at the access time that often. But it's usefull
> > > for diagnostics and statistics.
> > 
> > well, i have not heard any complaints about mtime either. (other than mine)
> > because mmap is rarely used, i guess.
> 
> You mean, mtime isn't updated for mmaped files either ? That's much more
> annoying, because backup tools relies on mtime for incremental backups.

yes.  i think i've filed a PR about it sometime ago.

> > you might want to use VM_PROT_NONE for VOP_GETPAGES in ufs_balloc_range as
> > what it actually does is just holding pages without accessing them.
> > then you can check VM_PROT_READ, which is more straightforward than
> > VM_PROT_WRITE.
> > 
> > however, i still don't like the idea to update atime in VOP_GETPAGES.
> > it sounds like "update randomly" to me.
> > if we want to update atime for mmap, i prefer to do it when a file is mmap'ed.
> 
> And do it again when it's unmapped then.

why on unmap?

> And the same for mtime, I guess.

for mtime, update on munmap might make sense.

YAMAMATO Takashi