Re: [PATCH 2/3] lockdep: clarify size for LOCKDEP_*_BITS configs

From: Carlos Llamas
Date: Tue Aug 06 2024 - 10:50:35 EST


On Mon, Aug 05, 2024 at 09:36:43PM -0400, Waiman Long wrote:
>
> Many kernel developers understand that BITS refers to a size of 2^n. Besides
> LOCKDEP, there are also many instances of such use in other kconfig entries.
> It can be a bit odd to explicitly state that just for LOCKDEP.
>
> Cheers,
> Longman

Right, and similar to BITS there is SHIFT, which is also a common way to
specify the 2^n values. I'd point out though, that it is also common to
clarify the "power of two" explicitly. To name a few examples that are
doing so: SECURITY_SELINUX_SIDTAB_HASH_BITS, NODES_SHIFT, CMA_ALIGNMENT,
IP_VS_SH_TAB_BITS, LOG_BUF_SHIFT but there is more.

Perhaps this is because the audience for these configs is not always a
kernel developer?

Anyway, this is pretty much a trivial patch to address Andrew's comment
below. But let me know if you think I should drop it, it seems to me it
can be helpful.

[...]
btw, the help text "Bitsize for MAX_LOCKDEP_CHAINS" is odd. What's a
bitsize? Maybe "bit shift count for..." or such.

Thanks,
--
Carlos Llamas