What's the meaning of CONFIG_BROKEN_ON_SMP?

[parmenides]

Hi,

I compiled a driver, ang get the following message:

CONFIG_BROKEN_ON_SMP: should be set in the kernel configuration, but isn't.

Somebody suggested to disable the kernel's SMP feature. I did, and the
problem got solved.

Then, I googled the meaning of CONFIG_BROKEN_ON_SMP, but did not get
definitive explanation, such as
http://cateee.net/lkddb/web-lkddb/BROKEN_ON_SMP.html

I wonder what the meaning of the configuration is. How does it work? Thx!