Re: Packages grow, no longer fit on a 💾

[John Kehayias <john.kehayias@protonmail.com>]

Hi all,

On Tue, Jan 17, 2023 at 05:18 PM, Ludovic Courtès wrote:

> Hi,
>
> Efraim Flashner <efraim@flashner.co.il> skribis:
>
>> I've made some progress on LLVM and I think I have a working LLVM that
>> can be used as an input for mesa.
>>
>> (ins)efraim@3900XT ~$ du -sch /gnu/store/36kmnxmb1h8pxw0x71wril67fdvjx7ny-llvm-11.0.0/*
>> 3.9M    /gnu/store/36kmnxmb1h8pxw0x71wril67fdvjx7ny-llvm-11.0.0/bin
>> 8.0K    /gnu/store/36kmnxmb1h8pxw0x71wril67fdvjx7ny-llvm-11.0.0/etc
>> 21M     /gnu/store/36kmnxmb1h8pxw0x71wril67fdvjx7ny-llvm-11.0.0/include
>> 67M     /gnu/store/36kmnxmb1h8pxw0x71wril67fdvjx7ny-llvm-11.0.0/lib
>> 16K     /gnu/store/36kmnxmb1h8pxw0x71wril67fdvjx7ny-llvm-11.0.0/share
>> 92M     total
>>
>> (define llvm-for-mesa
>>   (package/inherit llvm-11
>
> Yay, great news!  Let’s have that in ‘core-updates’.
>

Yes, very nice!

A note that after some debugging that latest mesa (22.2.3 as of today, to be updated on
core-updates) seems to want newer LLVM, namely llvm-15. Fortunately we have this LLVM
version thanks to other's hard work on this front.

I don't think there were any errors in building mesa with older LLVM, but on current
hardware (unfortunately brings in non-free considerations) this was necessary. I believe
this is the summary: <https://www.phoronix.com/news/LLVM-15-Branched>

Props to katco on IRC for going through some long building and debugging to track this
down. The end result is that mesa 22.2.x with llvm-15 gave proper support for current gen
hardware, both parts (and current kernel) being needed.

So, I'd vote for having llvm-for-mesa to be at the latest LLVM version as well as Mesa. As
per the discussion on another thread, this could make sense for a feature branch and to
get thorough testing. Seeing as how LLVM seems pretty core to what Mesa does these days, I
would feel better having that tested across different hardware and use cases. Again, I
think a singular feature branch works well for this and I'm happy to help out on that
front. But I'll leave those discussions to the other thread.

>> In addition to what I have below I found that nix has a patch to make
>> llvm-11 (and the others) use the GNUInstallDirs, so we'd be able to move
>> the include directory to another output, saving another 21MB, bringing
>> llvm-for-mesa down to 71MB. Another possibility would be to have
>> llvm-for-mesa use llvm as an input, and then to use some configure-flags
>> to tell llvm-for-mesa to use the includes from llvm (the input).
>
> Good.  We can make these changes incrementally, but having
> ‘llvm-for-mesa’ would already be a noticeable improvement.
>
> Thanks!
>
> Ludo’.

Thanks all, I'm here for smaller closures!
John