Re: locked history file

[Matt Armstrong <matt@rfc20.org>]

Gunnar Horrigmo <gnunar@stoffe-pro.net> writes:

> Has something changed recently regardomg how emacs handles the history
> file? I'm seeing this quite often now, when running multiple emacsen:
>
> Error running timer ‘savehist-autosave’: (file-locked "/home/gunnar/.config/emacs/emacs.d/history" "gunnar@titanium (pid 1039)")
>
> .. and while it's perfectly understandable, I've been running multiple
> emacsen for many, many years, and this feels new.
>
> This is on 27.1.91, btw.
>
> I apologise if this is too noobish for emacs-devel. I appreciate a
> pointer if I should've asked elsewhere.

Hi Gunnar,

I have been digging into the Emacs file locking code recently.  I don't
think much has changed with core mechanics locking mechancis or savehist
itself in recent Emacs versions.

How big is your history file?  Perhaps it is enormous, causing the IO to
take an unusualy long time.

How is your hard disk?  If it is seeing intermitten write slowness at
other times?  Could you be doing IO intensive tasks when these problems
occur?

When you run your multiple Emacs instances, do you launch them all at
the same time?  For example, at login?  If so, then the history save
timers would all happen at similar times, which would increase the
chance of a write lock conflict.

Those are all "shot in dark" guesses.

Feel free to file an Emacs bug on this.