TITLE: HP Tru64 UNIX - aio Related Performance Issue Copyright (c) Hewlett-Packard Company 2004. All rights reserved. PRODUCT: HP Tru64 UNIX [R] 5.1B SOURCE: Hewlett-Packard Company ECO INFORMATION: ECO Name: T64KIT0021909-V51BB24-E-20040317 ECO Kit Approximate Size: 4.14MB Kit Applies To: HP Tru64 UNIX 5.1B PK3 (BL24) ECO Kit CHECKSUMS: /usr/bin/sum results: 45606 4240 /usr/bin/cksum results: 3427011380 4341760 MD5 results: 30dd7c0dc42eb2c89440c99eed724b42 SHA1 results: 92628b30b64adfe769d2be7cb4cc7851b866b1e3 ECO KIT SUMMARY: A dupatch-based, Early Release Patch kit exists for HP Tru64 UNIX 5.1B that contains solutions to the following problem(s): - HP Tru64 UNIX - aio Related Performance Issue New code introduced into V5.1A BL24 (PK6) and V5.1B BL24 (PK3) to prevent an aio-related application deadlock has the potential to increase contention for the vm_umap lock. This lock contention could severely reduce aio throughput. This ERP corrects the new code introduced in BL24. It provides an improvement on the aio contention logic to reduce the occurrence of lock contention. - HP Tru64 UNIX - file region locks (set via fcntl or flock) can be inadvertently released as a result of AIO processing Applications that have code segments similar to the following example may experience the unintended release of the file lock. A sample scenario: 1) open file 2) take file region lock 3) initiate AIO 4) release file region lock 5) close file 6) open same file 7) take file region lock Should the AIO operation complete after the subsequent close, then it would perform the final unref against the target file. Should the AIO operation complete after the subsequent re-open of that same file, then that final unref would also release any file region locks held by that process on that file. If the AIO completed after the final step of taking a file region lock, then that lock would be mistakenly released. Customers whose systems run large scale database applications utilizing asynchronous I/O are encouraged to install this ERP. The Patch Kit Installation Instructions and the Patch Summary and Release Notes documents provide patch kit installation and removal instructions and a summary of each patch. Please read these documents prior to installing patches on your system. The patches in this ERP kit will also be available in the next mainstream patch kit - HP Tru64 UNIX 5.1B Patch Kit 4. INSTALLATION NOTES: 1) Install this kit with the dupatch utility that is included in the patch kit. You may need to baseline your system if you have manually changed system files on your system. The dupatch utility provides the baselining capability. 2) This ERP kit will NOT install over any Customer Specific Patches (CSPs) which have file intersections with this ERP kit. Contact your normal Service Provider for assistance if the installation of this ERP kit is blocked by any of your installed CSPs. INSTALLATION PREREQUISITES: You must have installed HP Tru64 UNIX 5.1B PK3 (BL24) prior to installing this Early Release Patch Kit. KNOWN PROBLEMS WITH THE PATCH KIT: None. RELEASE NOTES FOR T64KIT0021909-V51BB24-E-20040317: Release Notes This document summarizes the contents and special instructions for the Tru64 UNIX V5.1B patches contained in this kit. For information about installing or removing patches, baselining, and general patch management, see the Patch Kit Installation Instructions document. 1 Release Notes This Early Release Patch Kit Distribution contains: - fixes that resolve the problem(s) reported in: o 97700 DEK132895 DSATD1ZVW * for Tru64 UNIX V5.1B T64V51BB24AS0003-20030929.tar (BL24) The patches in this kit are being released early for general customer use. Refer to the Release Notes for a summary of each patch and installation prerequisites. Patches in this kit are installed by running dupatch from the directory in which the kit was untarred. For example, as root on the target system: > mkdir -p /tmp/CSPkit1 > cd /tmp/CSPkit1 > > tar -xpvf DUV40D13-C0044900-1285-20000328.tar > cd patch_kit > ./dupatch 2 Special Instructions There are no special instructions for Tru64 UNIX V5.1B Patch C564.02 3 Summary of CSPatches contained in this kit Tru64 UNIX V5.1B PatchId Summary Of Fix ---------------------------------------- C564.02 DSATD1ZVW/DEK132895: aio related performance issue 4 Additional information from Engineering None5 Affected system files This patch delivers the following files: Tru64 UNIX V5.1B Patch C564.02 ./sys/BINARY/std_kern.mod CHECKSUM: 04139 1519 SUBSET: OSFBIN540 [R] UNIX is a registered trademark in the United States and other countries licensed exclusively through X/Open Company Limited. Copyright Hewlett-Packard Company 2004. All Rights reserved. This software is proprietary to and embodies the confidential technology of Hewlett-Packard Company. Possession, use, or copying of this software and media is authorized only pursuant to a valid written license from Hewlett-Packard or an authorized sublicensor. This ECO has not been through an exhaustive field test process. Due to the experimental stage of this ECO/workaround, Hewlett-Packard makes no representations regarding its use or performance. The customer shall have the sole responsibility for adequate protection and back-up data used in conjunction with this ECO/workaround.