Patch Name: PHKL_30515

Patch Description: s700_800 11.11 'sar -d' reports inaccurate data

Creation Date: 04/03/24

Post Date: 04/05/06

Hardware Platforms - OS Releases:
	s700: 11.11
	s800: 11.11

Products: N/A

Filesets:
	OS-Core.CORE2-KRN,fr=B.11.11,fa=HP-UX_B.11.11_32,v=HP
	OS-Core.CORE2-KRN,fr=B.11.11,fa=HP-UX_B.11.11_64,v=HP

Automatic Reboot?: Yes

Status: General Release

Critical: No

Category Tags:
	defect_repair general_release

Path Name: /hp-ux_patches/s700_800/11.X/PHKL_30515

Symptoms:
	PHKL_30515:
	( SR:8606331074 CR:JAGae92195 )
	The -d option of the sar(1M) command reports inaccurate data
	in the "avwait", "avserv" and "%busy" columns.

	( SR:8606353599 CR:JAGaf14393 )
	There are no customer visible symptoms.

	PHKL_27200:
	( SR:8606249217 CR:JAGae15611 )

	"sar -d" reports incorrect values for avque and avwait.

	Example output:
	device %busy  avque    r+w/s blks/s avwait        avserv
	c17t1d1 66.00 60178.29 284   27206  2124620672.00 0.00
	c25t1d1 67.00 32767.50 296   28525  4.91          2.91
	c33t1d1 69.00 65531.50 294   28413  4.99          2.87
	c41t1d1 67.60 65534.50 316   29669  5.04          2.68
	c49t1d1 67.80 60426.86 310   29845  1295032832.00 0.00

Defect Description:
	PHKL_30515:
	( SR:8606331074 CR:JAGae92195 )
	The kernel uses two time sources with incompatible
	resolution to mark the start and end of disk transfers.
	The 10 millisecond sampling method of measuring busy
	time is inaccurate for most of the new and fast disks.

	Resolution:
	Use the same high resolution time source for IO timestamps
	in the 64-bit kernel. Replace sampling method by direct
	calculation of the busy time from the new timestamps. This
	solution does not address 32-bit kernels due to the high
	overhead of generating 64-bit timestamps.

	( SR:8606353599 CR:JAGaf14393 )
	The enqueue timestamp in the buf structure is not set at the
	correct time on the requeue path. This condition can only be
	detected by HP internal testing.

	Resolution:
	Initialize the timestamp at the requeue event.

	PHKL_27200:
	( SR:8606249217 CR:JAGae15611 )
	The filesystem merges the I/O buffers before sending them
	to the disk driver. The kernel routine used to measure
	and gather data for sar did not handle the combined
	buffers: it did not timestamp the individual elements in
	the merged list, nor record their lengths correctly.

	Resolution:
	The buffer enqueue routine is made aware of the merged
	lists. This problem has been fixed by timestamping the
	queue-time field of every buffer in the list in the
	buffer enqueue routine. This field is used in the
	computation of "avwait" field of the sar(1M) command.
	Also, in the case of a merged list of buffers, the fields
	corresponding to cumulative queue length and the
	number of buffers enqueued, associated with an I/O
	device, are updated as every buffer element is enqueued.
	These two fields are used in the computation of the
	"avque" field in the sar(1M) command.

Enhancement:
	No

SR:
	8606249217 8606331074 8606353599

Patch Files:
	
	OS-Core.CORE2-KRN,fr=B.11.11,fa=HP-UX_B.11.11_32,v=HP:
	/usr/conf/lib/libpm.a(kmetric.o)

	OS-Core.CORE2-KRN,fr=B.11.11,fa=HP-UX_B.11.11_64,v=HP:
	/usr/conf/lib/libpm.a(kmetric.o)

what(1) Output:
	
	OS-Core.CORE2-KRN,fr=B.11.11,fa=HP-UX_B.11.11_32,v=HP:
	/usr/conf/lib/libpm.a(kmetric.o):
		kmetric.c $Date: 2004/03/09 19:27:12 $Revision: r11.
			11/2 PATCH_11.11 (PHKL_30515)

	OS-Core.CORE2-KRN,fr=B.11.11,fa=HP-UX_B.11.11_64,v=HP:
	/usr/conf/lib/libpm.a(kmetric.o):
		kmetric.c $Date: 2004/03/09 19:27:12 $Revision: r11.
			11/2 PATCH_11.11 (PHKL_30515)

cksum(1) Output:
	
	OS-Core.CORE2-KRN,fr=B.11.11,fa=HP-UX_B.11.11_32,v=HP:
	2004861286 5760 /usr/conf/lib/libpm.a(kmetric.o)

	OS-Core.CORE2-KRN,fr=B.11.11,fa=HP-UX_B.11.11_64,v=HP:
	3148723872 14232 /usr/conf/lib/libpm.a(kmetric.o)

Patch Conflicts: None

Patch Dependencies: None

Hardware Dependencies: None

Other Dependencies: None

Supersedes:
	PHKL_27200 

Equivalent Patches: None

Patch Package Size: 30 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_30515

	5. Run swinstall to install the patch:

		swinstall -x autoreboot=true -x patch_match_target=true \
			  -s /tmp/PHKL_30515.depot

	By default swinstall will archive the original software in 
	/var/adm/sw/save/PHKL_30515.  If you do not wish to retain a
	copy of the original software, include the patch_save_files
	option in the swinstall command above:

		-x patch_save_files=false

	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_30515.text file is 
	available in the product readme:

		swlist -l product -a readme -d @ /tmp/PHKL_30515.depot

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

		dd if=/tmp/PHKL_30515.depot of=/dev/rmt/0m bs=2k

Special Installation Instructions: None