The laptop-mode hook tries to save the dirty_ratio and dirty_background_ratio
values before it modifies them.
This breaks, if the user set dirty_bytes or dirty_background_bytes before. In
that case the _ratio files will read as "0".
That in turn means that on "restore" of the "0" values to the _ratio files,
which happens on laptop-mode switch off, dirty memory ratio will be set to
zero. This heavily breaks disk write performance and renders the system mostly
unusable.

The proposed patch tries to fix this by aborting the hook, if any ratio field
is zero.

Dear submitter,

as the package pm-utils has just been removed from the Debian archive
unstable we hereby close the associated bug reports.  We are sorry
that we couldn't deal with your issue properly.

For details on the removal, please see https://bugs.debian.org/1058701

The version of this package that was in Debian prior to this removal
can still be found using https://snapshot.debian.org/.

Please note that the changes have been done on the master archive and
will not propagate to any mirrors until the next dinstall run at the
earliest.

This message was generated automatically; if you believe that there is
a problem with it please contact the archive administrators by mailing
ftpmaster@ftp-master.debian.org.

Debian distribution maintenance software
pp.
Thorsten Alteholz (the ftpmaster behind the curtain)