Re: [PATCH] [RFC, DO NOT APPLY] vmlinux.lds: revert link speed regression

From: Arnd Bergmann
Date: Tue Jan 21 2025 - 02:42:21 EST


On Tue, Jan 21, 2025, at 01:19, Masahiro Yamada wrote:
> On Tue, Jan 21, 2025 at 6:29 AM Arnd Bergmann <arnd@xxxxxxxxxx> wrote:
>>
>> linux-6.12 linux-6.13
>> ld.lld v20 1.2s 1.2s
>> ld.bfd v2.36 3.2s 5.2s
>> ld.bfd v2.39 59s 388s
>>
>
> Is this problem specific to the BFD linker from binutils?

I only tried the bfd and lld linkers, but I assume it's limited
to the bfd one.

> Did you observe a link speed regression with LLVM=1 build?

No, the ld.lld line above is what I see with LLVM=1, it's
very fast (1.2s) both before and after the change. New
ld.bfd versions were much slower before the regression
for this particular config and got even slower (seven minutes
for each of the three vmlinux link stages).

Arnd