Patch Name: PHKL_25055 Patch Description: s700_800 11.04 (VVOS) Cumulative gang scheduling patch Creation Date: 01/10/11 Post Date: 01/10/26 Hardware Platforms - OS Releases: s700: 11.04 s800: 11.04 Products: N/A Filesets: OS-Core.CORE2-KRN,fr=B.11.04,fa=HP-UX_B.11.04_32,v=HP OS-Core.CORE2-KRN,fr=B.11.04,fa=HP-UX_B.11.04_64,v=HP Automatic Reboot?: Yes Status: General Release Critical: No (superseded patches were critical) PHKL_21685: HANG Based on HP-UX patch PHKL_21549: HANG PHKL_23007: HANG Based on HP-UX patch PHKL_21549: HANG Category Tags: defect_repair general_release critical halts_system Path Name: /hp-ux_patches/s700_800/11.X/PHKL_25055 Symptoms: PHKL_25055: Redundancy of patch filesets PHKL_21685 and PHKL_23007. Both deliver same file without PHKL_23007 superseding PHKL_21685. PHKL_23007: Ported HP-UX patch PHKL_21549 to VVOS. Based on PHKL_21549: ( SR: 8606129909 DTS: JAGac88824 ) Gang scheduled applications appear to hang or make minimal forward progress. Based on PHKL_19315: ( SR: 1653280479 DTS: JAGaa42348 ) CPU usage of a mult-threaded job with gang-scheduling on is reduced drasticly while a single-threaded job with higher priority is running. PHKL_21685: Ported HP-UX patch PHKL_21549 for VVOS. Based on HP-UX patch PHKL_21549: ( SR: 8606129909 DTS: JAGac88824 ) Gang scheduled applications appear to hang or make minimal forward progress. Based on HP-UX patch PHKL_19315: ( SR: 1653280479 DTS: JAGaa42348 ) CPU usage of a mult-threaded job with gang-scheduling on is reduced drasticly while a single-threaded job with higher priority is running. Defect Description: PHKL_25055: Fixes a problem where PHKL_23007 delivered a patch fileset containing the same file delivered in PHKL_21685 without PHKL_23007 superseding PHKL_21685. PHKL_23007: Ported HP-UX patch PHKL_21549 to VVOS. Based on PHKL_21549: ( SR: 8606129909 DTS: JAGac88824 ) The gang scheduler did not recognize a new cpu state that was added to the system initialization process. This resulted in all gang scheduled processes being bound to the monarch processor. Resolution: At system initialization the gang scheduler now takes into account the new cpu state and uses all available processors instead of just the monarch. Based on PHKL_19315: ( SR: 1653280479 DTS: JAGaa42348 ) The GANG scheduling of multithreaded applications allows users to improve significantly the performance of their jobs that run on a subset of processors. In an enviroment that uses different priorities for the jobs, over-subscription becomes a problem: A singlethreaded job of high priority is able to reduce the CPU usage of all running multithreaded jobs. The expectation is that the singlethreaded job reduces in average the CPU usage of one gang independently from the priority of the singlethreaded job. Resolution: This patch to the gang scheduler removes a previous change that corrects the fairness algorithm of the gang scheduler load balancer. The code is reverted back to its original algorithm for when to initiate the gang scheduler load balancer. Balancing is not performed is we are under or completely subscribed. Only when the active gangs oversubscribe the available processors will the load balancer be initiated. PHKL_21685: Ported HP-UX patch PHKL_21549 for VVOS. Based on HP-UX patch PHKL_21549: ( SR: 8606129909 DTS: JAGac88824 ) The gang scheduler did not recognize a new cpu state that was added to the system initialization process. This resulted in all gang scheduled processes being bound to the monarch processor. Resolution: At system initialization the gang scheduler now takes into account the new cpu state and uses all available processors instead of just the monarch. Based on HP-UX patch PHKL_19315: ( SR: 1653280479 DTS: JAGaa42348 ) The GANG scheduling of multithreaded applications allows users to improve significantly the performance of their jobs that run on a subset of processors. In an enviroment that uses different priorities for the jobs, over-subscription becomes a problem: A singlethreaded job of high priority is able to reduce the CPU usage of all running multithreaded jobs. The expectation is that the singlethreaded job reduces in average the CPU usage of one gang independently from the priority of the singlethreaded job. Resolution: This patch to the gang scheduler removes a previous change that corrects the fairness algorithm of the gang scheduler load balancer. The code is reverted back to its original algorithm for when to initiate the gang scheduler load balancer. Balancing is not performed is we are under or completely subscribed. Only when the active gangs oversubscribe the available processors will the load balancer be initiated. SR: 1653280479 8606129909 Patch Files: OS-Core.CORE2-KRN,fr=B.11.04,fa=HP-UX_B.11.04_32,v=HP: /usr/conf/lib/libhp-ux.a(pm_gang.o) OS-Core.CORE2-KRN,fr=B.11.04,fa=HP-UX_B.11.04_64,v=HP: /usr/conf/lib/libhp-ux.a(pm_gang.o) what(1) Output: OS-Core.CORE2-KRN,fr=B.11.04,fa=HP-UX_B.11.04_32,v=HP: /usr/conf/lib/libhp-ux.a(pm_gang.o): pm_gang.c $Date: 2000/04/14 11:31:10 $Revision: r11r os/7 PATCH_11.00 (PHKL_21549) OS-Core.CORE2-KRN,fr=B.11.04,fa=HP-UX_B.11.04_64,v=HP: /usr/conf/lib/libhp-ux.a(pm_gang.o): pm_gang.c $Date: 2000/04/14 11:31:10 $Revision: r11r os/7 PATCH_11.00 (PHKL_21549) cksum(1) Output: OS-Core.CORE2-KRN,fr=B.11.04,fa=HP-UX_B.11.04_32,v=HP: 3922495959 17276 /usr/conf/lib/libhp-ux.a(pm_gang.o) OS-Core.CORE2-KRN,fr=B.11.04,fa=HP-UX_B.11.04_64,v=HP: 1077527354 43096 /usr/conf/lib/libhp-ux.a(pm_gang.o) Patch Conflicts: None Patch Dependencies: s700: 11.04: PHKL_19142 s800: 11.04: PHKL_19142 Hardware Dependencies: None Other Dependencies: None Supersedes: PHKL_23007 PHKL_21685 Equivalent Patches: PHKL_21549: s700: 11.00 s800: 11.00 Patch Package Size: 100 KBytes Installation Instructions: Please review all instructions and the Hewlett-Packard SupportLine User Guide or your Hewlett-Packard support terms and conditions for precautions, scope of license, restrictions, and, limitation of liability and warranties, before installing this patch. ------------------------------------------------------------ 1. Back up your system before installing a patch. 2. Login as root. 3. Copy the patch to the /tmp directory. 4. Move to the /tmp directory and unshar the patch: cd /tmp sh PHKL_25055 5. Run swinstall to install the patch: swinstall -x autoreboot=true -x patch_match_target=true \ -s /tmp/PHKL_25055.depot By default swinstall will archive the original software in /var/adm/sw/save/PHKL_25055. If you do not wish to retain a copy of the original software, use the patch_save_files option: swinstall -x autoreboot=true -x patch_match_target=true \ -x patch_save_files=false -s /tmp/PHKL_25055.depot WARNING: If patch_save_files is false when a patch is installed, the patch cannot be deinstalled. Please be careful when using this feature. For future reference, the contents of the PHKL_25055.text file is available in the product readme: swlist -l product -a readme -d @ /tmp/PHKL_25055.depot To put this patch on a magnetic tape and install from the tape drive, use the command: dd if=/tmp/PHKL_25055.depot of=/dev/rmt/0m bs=2k Special Installation Instructions: This patch depends on base patch PHKL_19142. For successful installation please insure that PHKL_19142 is already installed, or that PHKL_19142 is included in the same depot with this patch and PHKL_19142 is selected for installation.