RE: [PATCH v10 6/6] x86/split_lock: Enable split lock detection by kernel parameter

From: Luck, Tony
Date: Thu Dec 12 2019 - 14:46:29 EST


>> If anything we could switch the entire bitmap interface to unsigned int,
>> but I'm not sure that'd actually help much.
>
> As we've been looking for potential split lock issues in kernel code, most of
> the ones we found relate to callers who have <=32 bits and thus stick:
>
> u32 flags;
>
> in their structure. So it would solve those places, and fix any future code
> where someone does the same thing.

If different architectures can do better with 8-bit/16-bit/32-bit/64-bit instructions
to manipulate bitmaps, then perhaps this is justification to make all the
functions operate on "bitmap_t" and have each architecture provide the
typedef for their favorite width.

-Tony