Pmon failed to acquire latch, see pmon dump

Symptom:

Database Listener crash

Processing Process:

The database encountered an exception. After receiving the alarm, I immediately logged on to the server. LSNRCTL status found that Listener was dead and started quickly. The result lasted about 1 minute.

The database can be connected and returns to normal.

 

Next, find the cause of the problem and report the following error in the Alert Log: pmon failed to acquire latch, see pmon dump

 

A bug is found online.

 

Solution:The group discussion decides whether to install patches.

 

Pmon failed to acquire latch "messages in Alert Log-database hung [ID 468740.1]

 

In this document

 

Symptoms

Cause

Solution

References

 

 

This document is being delivered to you via Oracle Support's rapid visibility (RAV) process and therefore has not been subject to an independent technical review.

 

Applies:

Oracle Database-Enterprise Edition-version 10.2.0.1 to 11.1.0.7 [release 10.2 to 11.1]
Information in this document applies to any platform.
* ** Checked for relevance on 26-apr-2012 ***

Symptoms

Database instance hangs and connections to database using 'sqlplus 'are also not possible.

Checking alert. log we see following messages

 

Pmon failed to acquire latch, see pmon dump

Fri Oct 5 10:33:00 2007

Pmon failed to acquire latch, see pmon dump

Fri Oct 5 10:34:05 2007

Pmon failed to acquire latch, see pmon dump

Errors
In
File
/Dwrac/bdump/dwhp_pmon_1912834.trc:

 

This will also dump a systemstate dump and the location will be mentioned in alert. Log

Also at OS level, we see that Mman is consuming lot of CPU.

On checking the system state dump, we see that Mman is holding the Shared Pool latch and location
Latch is kgh_next_free or quiesce extents

So: 3df6835b8, type: 2, Owner: 0, flag: init/-/0x00
(Process) Oracle pid = 4, callcur/top: 3dfa94c48/3dfa94c48, flag: (6)
System
Int error: 0, call error: 0, sess error: 0, txn error 0
(Post info) Last post received ed: 0 0 24
(Latch info) wait_event = 0 bits = 80
Holding (EFD = 3) 3800db408 Child shared pool level = 7 child # = 1
Location from where latch is held:Kgh_next_free:
Context saved from call: 0
State = busy, wlstate = free
Waiter COUNT = 3
Process Group: Default, false proc: 3df77a4b8
O/s Info: User: oracle10, term: Unknown, ospid: 25931
Osd pid info: Unix process PID: 25931, image: Oracle @ dbname(Mman)

Short Stack wocould be like below
Kghquiesce_regular_extentKgh_next_freeKsmc_next_free kmgs_extract_mem_from_granule @ kmgs_check_inuse_lists

Cause

This issue was worked upon by Development in

Bug 6488694-database hung with pmon failed to acquire latch message

Bug 6488694 was closed as a duplicate of bug 7039896.

Solution

Please apply the patch 7039896 for your version and operating system.

Issue is fixed in:

• 11.2.0.1 (Base Release)
• 10.2.0.5 (server patch set)
• 10.2.0.4.1 (Patch Set Update)
• 10.2.0.4 patch 22 on Windows Platforms

Please refer
Note 7039896.8-bug 7039896-spin under kghquiesce_regular_extent holding Shared Pool latch with AMM

Workarounds that can be used:

• Disable Automatic shared memory management (Asmm) I. e settingSga_target = 0

  -Or-

• Set the init. ora parameter _ enable_shared_pool_durations = false

References

BUG: 6488694-Databse hung with pmon failed to acquire latch message

Note: 7039896.8-bug 7039896-spin under kghquiesce_regular_extent holding Shared Pool latch with AMM