Re: linux-next: manual merge of the akpm tree with the tip tree

From: Peter Zijlstra
Date: Fri Mar 31 2017 - 10:46:08 EST


On Fri, Mar 31, 2017 at 06:54:48AM -0700, Andi Kleen wrote:
> > Argh!
> >
> > Andrew, please drop that patch. And the x86 out-of-line of __atomic_add_unless().
>
> Why dropping the second? Do you have something better?

The try_cmpxchg() patches save about half the text, and do not have the
out-of-line penalty as shown here:

https://lkml.kernel.org/r/20170322165144.dtidvvbxey7w5pbd@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

> On the first there were no 0day regressions, so at least basic performance
> checking has been done.

The first is superseded by much better patches in the scheduler tree.