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

[Linus Torvalds]

On Tue, Sep 22, 2015 at 11:53 AM, Tejun Heo <tj@xxxxxxxxxx> 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
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