finding shared memory


 
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# 1  
Old 06-18-2009
finding shared memory

Using pmap, I was able to get a memory map of an Oracle process. It had the following id:
0000000380000000 4194320K rwxsR [ ism shmid=0x1500007a ]

Converting that Hex ID to decimal gave:
352321658

So, then I did ipcs -am:


IPC status from <running system> as of Thu Jun 18 15:43:17 MDT 2009
T ID KEY MODE OWNER GROUP CREATOR CGROUP NATTCH SEGSZ CPID LPID ATIME DTIME CTIME
Shared Memory:
m 385876003 0xaabe9228 --rw-r----- oracle dba oracle dba 40 809500672 1470 21027 15:43:02 15:43:03 22:26:30
m 369098782 0x8e4b02f0 --rw-r----- oracle dba oracle dba 69 159383552 29442 20780 15:41:35 15:41:35 17:01:59
m 352321620 0x3039 --rw-rw-rw- oracle dba oracle dba 0 4304 21321 27950 8:27:39 8:44:17 8:07:52
m 654311538 0xa23b56d0 --rw-r----- oracle dba oracle dba 44 1598029824 26886 26041 15:42:45 15:43:16 16:12:42
m 33554497 0x64747336 --rw-rw-rw- oracle dba oracle dba 0 4096 22220 15248 20:18:42 20:18:43 20:01:04


How come that ID retrieved earlier does not show up in the ipcs -am command? Is it in a different unit?
# 2  
Old 06-19-2009
ISM=Intimate Shared Memory i.e. shared memory is locked by the kernel when the segment is created and cannot be paged out. So it should show up in the ipcs output.
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