Re: Back-patch use of unnamed POSIX semaphores for Linux?

On Wed, Dec 7, 2016 at 3:12 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> On Tue, Dec 6, 2016 at 11:54 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>>>> On Tue, Dec 6, 2016 at 9:53 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>>>> I think we should give serious consideration to back-patching commit
>>>>> ecb0d20a9, which changed the default semaphore type to unnamed-POSIX
>>>>> on Linux.
>
>>>> Urk. That sounds like a scary thing to back-patch.
>
>>> I don't deny that it's scary, but the alternative seems to be to be
>>> rather badly broken on systemd-using distros for years to come.
>>> That's pretty scary too.
>
>> Why can't this be configurable?
>
> It already is. Note that I said "default".
>
> As things stand, it's only a configure-time choice, but I've been
> thinking that we might be well advised to make it run-time configurable.

Sure. A configure-time choice only benefits people who are compiling
from source, which as far as production is concerned is almost nobody.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company