[Devel] Re: [PATCH v4 1/3] make jump_labels wait while updates are in place

[Steven Rostedt]

On Fri, 2012-04-27 at 09:53 -0400, Jason Baron wrote:

> Right, for x86 which uses stop_machine currently, we guarantee that all
> cpus are going to see the updated code, before the inc of key->enabled.
> However, other arches (sparc, mips, powerpc, for example), seem to be
> using much lighter weight updates, which I hope are ok :)

And x86 will soon be removing stop_machine() from its path too. But all
archs should perform some kind of memory sync after patching code. Thus
the update should be treated as if a memory barrier was added after it,
and before the inc.

-- Steve