Re: [PATCH UPDATED] percpu: use dynamic percpu allocator as the default percpu allocator

Matthew Wilcox
2009-04-01T20:13:15Z

On Wed, Apr 01, 2009 at 12:39:46PM -0700, Linus Torvalds wrote:
> The thing is, things like "read_mostly" or "access_rarely" may talk about
> how we access those individual variables, but you're missing a _huge_
> chunk of the puzzle if you ignore the _correlations_ of those accesses
> with accesses to other variables.
>
> The thign is, if you have variables 'a' and 'b', and they are always
> accessed together, then it's probably worth it to put them in the same
> cacheline.

If you've got two global variables that are generally accessed together,
they should probably be `annotated' as such by putting them in a struct.

--
Matthew Wilcox Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours. We can't possibly take such
a retrograde step."