Re: [PATCH v2] netlink: Replace rhash_portid with bound

On Tue, Sep 22, 2015 at 11:53 AM, Tejun Heo [off-list ref] wrote:

I see.  The write path here is cold so the competition is between rmb
and acquire.  Unless some significant archs completely screwed it up,
acquire still seems like the better option.  It's essentially free on
x86 after all.

Both acquire and smp_rmb() are equally free on x86.

It appears that we don't do the X86_PPRO_FENCE bug handling for
acquire, but I guess we should.

Or possibly we should start deprecating the insane X86_PPRO_FENCE
entirely. It's very costly, for dubious advantages.

                  Linus