Hi,
On AIX, since with MMAP we have only 4K pages though we can have 64K pages with
SYSV, we'd like to experiment with SYSV rather than MMAP and measure the impact
to the performance.
Looking at file: src/include/storage/dsm_impl.h , it seemed to me that
replacing the line:
#define DEFAULT_DYNAMIC_SHARED_MEMORY_TYPE DSM_IMPL_POSIX
by the line:
#define DEFAULT_DYNAMIC_SHARED_MEMORY_TYPE DSM_IMPL_SYSV
was the right thing to do. Plus some changes like:
export LDR_CNTRL=SHMPSIZE=64K
ldedit -btextpsize=64k -bdatapsize=64k -bstackpsize=64k ...../postgres
However, when looking at details by means of procmap tool, it is unclear if
that worked or not.
Maybe I was lost by the variables:
HAVE_SHM_OPEN . USE_DSM_POSIX . USE_DSM_SYSV . USE_DSM_MMAP
which are all defined.
So, what should I do in order to use SYSV rather than MMAP for the Shared
Memory ?
(PostgreSQL v11.1)
Thanks/Regards,
Cordialement,
Tony Reix
tony.r...@atos.net
ATOS / Bull SAS
ATOS Expert
IBM Coop Architect & Technical Leader
Office : +33 (0) 4 76 29 72 67
1 rue de Provence - 38432 Échirolles - France
www.atos.net<https://mail.ad.bull.net/owa/redir.aspx?C=PvphmPvCZkGrAgHVnWGsdMcDKgzl_dEIsM6rX0g4u4v8V81YffzBGkWrtQeAXNovd3ttkJL8JIc.&URL=http%3a%2f%2fwww.atos.net%2f>
