RE: oracle handing memory allocation different between 11g and 12c?

From: Matt Adams <>
Date: Tue, 16 Feb 2016 18:37:45 +0000
Message-ID: <>

  Can you tell me which version and release of Solaris you are using?


-----Original Message-----
From: Stefan Koehler [] Sent: Tuesday, February 16, 2016 12:07 PM To: Matt Adams
Subject: RE: oracle handing memory allocation different between 11g and 12c?

Hi Matt,
not quite sure what's wrong in your env. OSM and works like a charm here :)

root_at_SOL:~# pmap -xs 1827
1827: ora_smon_S12DB

         Address Kbytes RSS Anon Locked Pgsz Mode Mapped File …

0000000060000000       4096       4096          -       4096   2M rwxs-    [ osm shmid=0x5000009 ]
0000000080000000      98304      98304          -      98304    - r-xs-    [ osm shmid=0x500000a ]
00000000C0000000    3981312    3981312          -    3981312   2M rwxs-    [ osm shmid=0x500000b ]
00000001C0000000      14336      14336          -      14336   2M rwxs-    [ osm shmid=0x500000c ]

Please DTrace the corresponding syscalls to get a better insight in your case.

root_at_SOL:~# dtrace -l

   ID   PROVIDER            MODULE                          FUNCTION NAME
  256    syscall                                             memcntl entry
  257    syscall                                             memcntl return
20833        fbt           genunix                           memcntl entry
20834        fbt           genunix                           memcntl return
78362        fbt            shmsys                        shmget_osm entry
78363        fbt            shmsys                        shmget_osm return
78364        fbt            shmsys                            shmget entry
78365        fbt            shmsys                            shmget return

Best Regards
Stefan Koehler

Freelance Oracle performance consultant and researcher Homepage:
Twitter: _at_OracleSK

> Matt Adams <> hat am 16. Februar 2016 um 16:28 geschrieben:
> But in 12c, Oracle prefers using OSM over either ISM or DISM. That appears to be the cause the of the problems I’m having.
> Anybody else install 12c on solaris and have issues with OSM not working as expected?
> Matt

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