BU040604_EW01
 
HP Tru64 UNIX Memory Leak in Bucket 1(32-byte bucket) When Running vfast

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 Advisory Information
 

RELEASE DATE: 25 April 2005 (Rev. 1)

Update of 25 April 2005

The Tru64 UNIX 5.1B-1/PK3 Early Release Patch (ERP) kit announced in this Engineering Advisory (EA) has been replaced by a new 5.1B-1/PK3 ERP kit. The new ERP, T64KIT0025392-V51BB24-E-20050418.tar, combines the memory leak fix described in this EA with two additional fixes that also affect advfs.mod. The new fixes avoid two panics resulting from quotactl requests on AdvFS filesets:

  • kernel memory fault in dyn_hash_remove
  • panic "lock_terminate: lock held"

See EA BU050414_EW01 (Panics During quotactl Calls) for details on the new fixes.

The 5.1B PK2 kit announced in this EA remains unchanged.

The original problem description follows.

DESCRIPTION
A memory leak exists in a routine that vfast uses to merge extent maps. The routine is not freeing allocated memory in bucket 1 (32-byte bucket). The problem manifests as an inordinate amount of memory being used in bucket 1. It can be identified by issuing the vmstat -M command and viewing the bytes_in_use column for bucket 1.

This problem only occurs when using vfast. The workaround is to issue "vfast deactivate dmnName" for all domains with vfast activated.

ERP Kit Notes

The memory leak is present in HP Tru64 UNIX V5.1B PK2 and V5.1B PK3. HP has resolved the problem by providing the two ERP kits listed in the Resolution section.

Both kits contain a revised advfs.mod.

The V5.1B PK3 ERP Kit

The 5.1B-1/PK3 kit now contains three fixes:

  • The memory leak fix described in this EA
  • kernel memory fault in dyn_hash_remove (new)
  • panic "lock_terminate: lock held" (new)

The V5.1B PK2 ERP Kit

The V5.1B PK2 kit combines the memory leak fix with two previous V5.1B PK2 fixes that also affect advfs.mod. The earlier fixes were released as V5.1B PK2 ERP kits and are being combined with the memory leak fix for customer convenience. Both previous fixes are available in V5.1B PK3 (BL24).

Specifically, the HP Tru64 UNIX V5.1B PK2 ERP kit contains fixes that address the following three issues:

  • Memory leak in bucket 32 when using vfast, which is described in this EA
     
  • AdvFS panic in _OtsMove
    A system can panic with a kernel memory fault in _OtsMove if threads are performing AdvFS direct I/O read operations. The panicing thread in the crash has the following stack trace segment:
       [...]
       6 _XentMM
       7 _OtsMove
       8 uiomove
       9 uiomove_frag
      10 fs_read
       [...]
     
  • Possible Memory Corruption:
    Under certain circumstances, memory corruption can occur when a non-Tru64 UNIX NFS client attempts to increase the size of an AdvFS file. The problem usually appears as a kernel memory fault and corruption in multiple kernel memory buckets. A thread in the crash has the following stack trace segment:
       [...]
       5 _OtsZero
       6 fs_setattr
       [...]
     
 

SCOPE
The following product versions are affected :

  • HP Tru64 UNIX V5.1B-1/PK3
  • HP Tru64 UNIX V5.1B PK2
 

RESOLUTION
HP is releasing the following ERPs publicly for use by any customer. The ERP kits use dupatch to install and will not install over any Customer Specific Patches (CSPs) that have file intersections with the ERP.

The fixes contained in the ERP kits are scheduled to be available in the following mainstream patch kit:

  • HP Tru64 UNIX V5.1B-2/PK4

Early Release Patches

ERP kits are available for the following versions. The kits distribute the following file:

/sys/BINARY/advfs.mod

HP Tru64 UNIX V5.1B-1/PK3
ERP Kit Name: T64KIT0025392-V51BB24-E-20050418.tar
Kit Location:
http://www.itrc.hp.com/service/patch/patchDetail.do?patchid=T64KIT0025392-V51BB24-E-20050418

(The V5.1B-1/PK3 kit contains the memory leak fix described in this EA and fixes for two panics.)

HP Tru64 UNIX V5.1B
PREREQUISITE: HP Tru64 UNIX with 5.1B with PK2 (BL22) installed
ERP Kit Name: T64KIT0022688-V51BB22-E-20040618.tar
Kit Location:
http://www.itrc.hp.com/service/patch/patchDetail.do?patchid=T64KIT0022688-V51BB22-E-20040618