[#QA-20] ORA-00600 [723]: Memory leak in LGWR.

Comment by ubTools Support [ 15/Jul/07 05:17 PM ]

Error code:

 
ORA-00600: internal error code, arguments: [723], [5200], [5200], [memory leak], [], [], [], []

Oracle kernel function from which the problem is raised:

 
ksmdpg()

Deallocate variable PGA. Just free top PGA heap, the callback will free. the extents to the OSD.
Ref: Bug:1283286

Process state:

 
PROCESS STATE
-------------
Process global information:
    process: 0, call: 0, xact: 0, curses: 0, usrses: 0
No process is allocated.
END OF PROCESS STATE

PGA Heap dump:

 

******** ERROR: PGA memory leak detected 5200 > 3616 ********
******************************************************
HEAP DUMP heap name="pga heap"  desc=0x40003190
extent sz=0x2148 alt=40 het=32767 rec=0 flg=3 opc=3
parent=0 owner=0 nex=0 xsz=0x2148
EXTENT 0
 Chunk 400de8e0 sz=     4432    free      "               "
 Chunk 400dfa30 sz=      256    freeable  "LGWR PIC bds ar"
 Chunk 400dfb30 sz=      896    freeable  "LGWR PIC ins ar"
 Chunk 400dfeb0 sz=      896    freeable  "LGWR PIC ins ar"
 Chunk 400e0230 sz=      568    free      "               "
 Chunk 400e0468 sz=      896    freeable  "LGWR PIC ins ar"
 Chunk 400e07e8 sz=      568    free      "               "
EXTENT 1
.

Problem explanation:

As seen above and included in your trace, the memory class of some chunks are "LGWR PIC ins ar" and similar. If you notice that sum of them is 5200 bytes, and they are freeable chunks. These chunks are leaked.

Also, there is no allocated process for LGWR. The most probably, you are closing the database.

Workaround:

There is no data corruption in this error, and can be safely ignore for small memory leaks by adding the following event to init.ora:

event = "10262 trace name context forever, level 6000"

Then, restart your database. This event disables space leaks less than 6000 bytes.

You can see the details at Metalink Note:39308.1 ORA-600 [723] "PGA memory leak"

Bug:

Bug:1125724 ORA-600[723] DURING SHUTDOWN

[QA-20] ORA-00600 [723]: Memory leak in LGWR. Created: 15/Jul/07 Updated: 16/Sep/07
Status:	Closed
Project:	Questions & Answers
Fix Version/s:	None