Messages in this thread | | | Date | Mon, 13 Jun 2016 12:45:23 -0700 | From | Davidlohr Bueso <> | Subject | Re: [PATCH] locking/qspinlock: Use atomic_sub_return_release in queued_spin_unlock |
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On Fri, 03 Jun 2016, Pan Xinhui wrote:
>The existing version uses a heavy barrier while only release semantics >is required. So use atomic_sub_return_release instead. > >Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> >Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
I just noticed this change in -tip and, while I know that saving a barrier in core spinlock paths is perhaps a worthy exception, I cannot help but wonder if this is the begging of the end for smp__{before,after}_atomic().
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