[PATCH 1/2] [PING] Optimize generic spinlock code and use C11 like atomic macros.

[Torvald Riegel]

On Wed, 2017-05-10 at 15:00 +0200, Stefan Liebler wrote:
> On 05/03/2017 01:38 PM, Stefan Liebler wrote:
> > On 04/25/2017 08:46 AM, Stefan Liebler wrote:
> >> On 04/18/2017 03:09 PM, Stefan Liebler wrote:
> >>> On 04/10/2017 01:59 PM, Stefan Liebler wrote:
> >>>> On 04/09/2017 03:51 PM, Torvald Riegel wrote:
> >>>>> On Fri, 2017-04-07 at 18:22 +0200, Stefan Liebler wrote:
> >>>>>> @architecture maintainers:
> >>>>>> I've added defines of ATOMIC_EXCHANGE_USES_CAS in the architecture
> >>>>>> specific atomic-machine.h files.
> >>>>>> See comment in include/atomic.h:
> >>>>>> /* ATOMIC_EXCHANGE_USES_CAS is equal to 1 if atomic_exchange
> >>>>>> operations
> >>>>>>     are implemented based on a CAS loop; otherwise, this is 0 and we
> >>>>>> assume
> >>>>>>     that the atomic_exchange operations could provide better
> >>>>>> performance
> >>>>>>     than a CAS loop.  */
> >>>>>>
> >>>>>> Can review the definition to 0 or 1 in the atomic-machine.h file of
> >>>>>> your
> >>>>>> architecture, please?
> >>>
> >>>
> >>> PING
> >>>
> >> PING
> >
> > PING
> 
> PING
> 
> @Torvald:
> I'm not sure if we will get answers from everybody.
> What do you propose how to proceed with the definitions of 
> ATOMIC_EXCHANGE_USES_CAS?

Which archs are still missing?  If maintainers don't reply, I suggest we
do our best to figure out what's the case for each missing arch, and add
a note that it should be checked eventually (eg, /* XXX Is this actually
correct?  */) to the code, and then commit.  Please CC: me on such a
patch, so I can have a last look at it.