Re: [PATCH v5 2/5] grub-mkconfig linux_xen: Fix quadratic algorithm for sorting menu items

[Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>]

----- On Jun 10, 2022, at 4:00 PM, Jason Andryuk jandryuk@xxxxxxxxx wrote:

> On Thu, Jun 9, 2022 at 2:50 PM Mathieu Desnoyers
> <mathieu.desnoyers@xxxxxxxxxxxx> wrote:
>>
>> The current implementation of the 20_linux_xen script implements its
>> menu items sorting in bash with a quadratic algorithm, calling "sed",
>> "sort", "head", and "grep" to compare versions between individual lines,
>> which is annoyingly slow for kernel developers who can easily end up
>> with 50-100 kernels in their boot partition.
>>
>> This fix is ported from the 10_linux script, which has a similar
>> quadratic code pattern.
>>
>> [ Note: this is untested. I would be grateful if anyone with a Xen
>>   environment could test it before it is merged. ]
> 
> Hi, Mathieu,
> 
> I tested by manually applying patch 2/5 on top of Fedora 36's
> installed /etc/grub.d/20_linux_xen, and manually applying patch 1/5 to
> /usr/share/grub/grub-mkconfig_lib.  It seems to generate grub.cfg
> menuentry-ies in the correct order.

Noted. Added your Tested-by to patch 2/5. Thanks!

> 
> Note for patch 1/5, it's best practice to use "$@" with the double
> quotes to prevent word splitting of arguments.  Doesn't really matter
> for that function at this time though.

I'll update patch 1/5 with this change. It's best practice indeed. I notice
that there are quite a few other places in grub-mkconfig_lib.in that do
follow this best practice though.

Thanks,

Mathieu

> 
> Regards,
> Jason

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