Re: [PATCH v3] grub-mkconfig linux: Fix quadratic algorithm for sorting menu items

[Mathieu Desnoyers <mathieu.desnoyers@efficios.com>]

----- On May 19, 2022, at 2:36 PM, Daniel Kiper dkiper@net-space.pl wrote:
[...]
> 
> Could you do the same in util/grub.d/20_linux_xen.in? Both should be
> kept in sync. And you are not first one who updates 10_linux.in only.
> If you could make a patch which adds something like "Keep logic in sync
> with..." to the util/grub.d/10_linux.in and util/grub.d/20_linux_xen.in
> that would be perfect.

AFAIU, 20_linux_xen.in does:

while [ "x${xen_list}" != "x" ] ; do
    list="${linux_list}"
    current_xen=`version_find_latest $xen_list`
    [....]
    while [ "x$list" != "x" ] ; do
        linux=`version_find_latest $list`
        [...]
        list=`echo $list | tr ' ' '\n' | fgrep -vx "$linux" | tr '\n' ' '`
    done
    if [ x"$is_top_level" != xtrue ]; then
        echo '  }'
    fi
    xen_list=`echo $xen_list | tr ' ' '\n' | fgrep -vx "$current_xen" | tr '\n' ' '`
done

Which adds yet another loop iterating on each item of "xen_list". For each of those,
there is an iteration on "linux_list".

I can do the change, like I can do the change for other OSes, but I don't have
the environment to test those changes. Would you be OK if I submit an untested
patch for someone else to try out ?

I notice that 10_hurd.in and 10_kfreebsd.in also have the exact same inefficient pattern.
Would you be OK if I also change them and let the change be tested by those who have
those environments ?

> 
> Did you consider Oskari's comment sent in the other email?

I just did, sorry for the delay, I missed his email because it was only
sent to the list.

Thanks,

Mathieu

> 
> Daniel

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com