Re: Re: [PATCH] BUG #13416: Postgres =?utf-8?Q?>=3D_?=9.3 doesn't use optimized shared memory on Solaris anymore

Fair enough.  We observed a ~4x amplification in memory usage so it was rather severe in our case.

The patch you referenced was a much nicer approach and Sam updated it to match that style (thank you Sam!).  We debated this internally and feel strongly that this should be exposed as a runtime GUC as suggested.  What's your take on the attached patch?

-sc

--
Sean Chittenden
seanc(at)joyent(dot)com

On Oct 4, 2017, 10:56 AM -0700, Andres Freund <andres(at)anarazel(dot)de>, wrote:
> Hi,
>
> On 2017-10-04 10:47:06 -0700, Sean Chittenden wrote:
> > Hello.  We identified the same problem.  Sam Gwydir and Josh Clulow were able to put together the appropriate fix after.
> >
> > The breakage in src/backend/port/sysv_shmem.c and src/include/storage/dsm_impl.h should be back ported to all supported versions (the regression was introduced between the 9.2 and 9.3 branches).
>
> Personally I don't think "breakage" is quite the right work.
>
> I also don't like that we're unconditionally not using
> USE_ANONYMOUS_SHMEM - doesn't that run into similar config limits on
> solaris based stuff as it does on linux etc?
>
> I think if we want to do this, we should rather go with a patch like
> https://www.postgresql.org/message-id/20140422121921.GD4449@awork2.anarazel.de
>
> Greetings,
>
> Andres Freund