[PATCH] Linux: Implement membarrier function

[Florian Weimer]

* Rich Felker:

> On Wed, Nov 28, 2018 at 04:05:01PM +0100, Florian Weimer wrote:
>> This is essentially a repost of last year's patch, rebased to the glibc
>> 2.29 symbol version and reflecting the introduction of
>> MEMBARRIER_CMD_GLOBAL.
>> 
>> I'm not including any changes to manual/ here because the set of
>> supported operations is evolving rapidly, we could not get consensus for
>> the language I proposed the last time, and I do not want to contribute
>> to the manual for the time being.
>> 
>> Thanks,
>> Florian
>> 
>> 2018-11-28  Florian Weimer  <fweimer@redhat.com>
>> 
>> 	Linux: Implement membarrier function.
>> 	* sysdeps/unix/sysv/linux/Makefile (sysdep_headers): Add
>> 	sys/membarrier.h.
>> 	(tests): Add tst-membarrier.
>> 	* sysdeps/unix/sysv/linux/Versions (GLIBC_2.27): Add membarrier.
>> 	* sysdeps/unix/sysv/linux/sys/membarrier.h: New file.
>
> I notice that the declaration moved from sys/mman.h to this new header
> since the previous version of this patch. Is this an intentional
> change,

Yes, it makes it clearer how we avoid maintaining a separate list of
constants for this.

> and is it where everyone now intends/agrees for it to be when
> it gets merged?

I don't know if there is consensus, sorry.

Thanks,
Florian