Patch Name: PHKL_21180

Patch Description: s700_800 11.00 Improved largepage performance for data

Creation Date: 00/03/02

Post Date:  00/03/06

Hardware Platforms - OS Releases:
	s700: 11.00
	s800: 11.00

Products: N/A

Filesets:
	OS-Core.CORE2-KRN,fr=B.11.00,fa=HP-UX_B.11.00_32,v=HP
	OS-Core.CORE2-KRN,fr=B.11.00,fa=HP-UX_B.11.00_64,v=HP

Automatic Reboot?: Yes

Status: General Release

Critical: No

Category Tags:
	enhancement general_release

Path Name: /hp-ux_patches/s700_800/11.X/PHKL_21180

Symptoms:
	PHKL_21180:
	( SR: 8606128648 CR: JAGac86195 )
	Private data regions for some applications (initialized
	data and bss) do not get good POPS (Performance Optimized
	Page Sizes, a.k.a. large-page) performance despite hints
	for large page sizes.
	OR
	When the application is linked with a linker which has
	patch PHSS_20014, POPS performance degrades with
	larger page size hints.

Defect Description:
	PHKL_21180:
	( SR: 8606128648 CR: JAGac86195 )
	The kernel will not provide a large page for data
	(initialized plus bss) if the total size of initialized data
	plus bss is less than the page size desired. Thus, for any
	application, there will be a limiting page size beyond which
	no improvement in page size will be observed. To overcome
	this, there is a linker patch PHSS_20014 that pads the data
	to the required size (when used with the +paddata option).
	If this linker patch (PHSS_20014) is used, then it is seen
	that large page performance improves upto a point, then
	degrades and stays constant with increasing pagesize hint.
	The use of PHSS_20014 without this patch also results in
	the application using up more memory for data.

	Resolution: In combination with PHSS_20014, which must be
	used for linking the application which needs good POPS
	performance, this patch will allow the kernel to
	use the padded data segment for bss and part of the heap.
	This improves large page performance and eliminates the
	wastage mentioned above.

SR:
	8606128648

Patch Files:
	
	OS-Core.CORE2-KRN,fr=B.11.00,fa=HP-UX_B.11.00_32,v=HP:
	/usr/conf/lib/libhp-ux.a(vm_text.o)

	OS-Core.CORE2-KRN,fr=B.11.00,fa=HP-UX_B.11.00_64,v=HP:
	/usr/conf/lib/libhp-ux.a(vm_text.o)

what(1) Output:
	
	OS-Core.CORE2-KRN,fr=B.11.00,fa=HP-UX_B.11.00_32,v=HP:
	/usr/conf/lib/libhp-ux.a(vm_text.o):
		vm_text.c $Date: 2000/02/28 11:27:29 $Revision: r11r
			os/5 PATCH_11.00 (PHKL_21180)

	OS-Core.CORE2-KRN,fr=B.11.00,fa=HP-UX_B.11.00_64,v=HP:
	/usr/conf/lib/libhp-ux.a(vm_text.o):
		vm_text.c $Date: 2000/02/28 11:27:29 $Revision: r11r
			os/5 PATCH_11.00 (PHKL_21180)

cksum(1) Output:
	
	OS-Core.CORE2-KRN,fr=B.11.00,fa=HP-UX_B.11.00_32,v=HP:
	1172160334 14276 /usr/conf/lib/libhp-ux.a(vm_text.o)

	OS-Core.CORE2-KRN,fr=B.11.00,fa=HP-UX_B.11.00_64,v=HP:
	2152006457 31752 /usr/conf/lib/libhp-ux.a(vm_text.o)

Patch Conflicts: None

Patch Dependencies:
	s700: 11.00: PHKL_18543
	s800: 11.00: PHKL_18543

Hardware Dependencies: None

Other Dependencies: None

Supersedes: None

Equivalent Patches: None

Patch Package Size: 80 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_21180

	5. Run swinstall to install the patch:

		swinstall -x autoreboot=true -x patch_match_target=true \
			  -s /tmp/PHKL_21180.depot

	By default swinstall will archive the original software in 
	/var/adm/sw/save/PHKL_21180.  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_21180.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_21180.text file is 
	available in the product readme:

		swlist -l product -a readme -d @ /tmp/PHKL_21180.depot

	To put this patch on a magnetic tape and install from the
	tape drive, use the command:

		dd if=/tmp/PHKL_21180.depot of=/dev/rmt/0m bs=2k

Special Installation Instructions:
	This patch depends on base patch PHKL_18543.
	For successful installation please insure that PHKL_18543
	is already installed, or that PHKL_18543 is included
	in the same depot with this patch and PHKL_18543
	is selected for installation.