Re: [PATCH v3 0/4] btf: support ints larger than 128 bits

From: Martin KaFai Lau
Date: Tue Jan 05 2021 - 14:52:50 EST


On Tue, Jan 05, 2021 at 02:45:30PM +0000, Sean Young wrote:
> clang supports arbitrary length ints using the _ExtInt extension. This
> can be useful to hold very large values, e.g. 256 bit or 512 bit types.
>
> Larger types (e.g. 1024 bits) are possible but I am unaware of a use
> case for these.
>
> This requires the _ExtInt extension enabled in clang, which is under
> review.
1. Please explain the use case.
2. All patches have the same commit message which is not useful.
Please spend some time in the commit message to explain what each
individual patch does.
3. The test_extint.py is mostly a copy-and-paste from the existing
test_offload.py? Does it need most of the test_offload.py
to test the BTF 256/512 bit int? Please create a minimal
test and use the test_progs.c infra-structure.