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

[Daniel Kiper]

On Thu, May 19, 2022 at 04:52:54PM -0400, Mathieu Desnoyers wrote:
> ----- 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 ?

In case of Xen I think you can CC xen-devel@lists.xenproject.org and ask
for help there.

> I notice that 10_hurd.in and 10_kfreebsd.in also have the exact same 
> inefficient pattern.

I think Samuel, CC-ed, could help with Hurd. Samuel? Just CC him when
you send next patch.

I am not sure who could help with FreeBSD.

> Would you be OK if I also change them and let the change be tested by those 
> who have
> those environments ?

Yeah, it is OK.

FYI, I am going to push at the beginning of next week Oskari's patch
which updates both util/grub.d/10_linux.in and util/grub.d/20_linux_xen.in.
So, please hold on with posting your patches until then to avoid
conflicts later.

> > 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.

No worries. It happens.

Daniel