Patch Name: PHKL_19002

Patch Description: s700 10.26 Buffer cache fixes for hangs and performance

Creation Date: 99/09/03

Post Date:  99/11/16

Hardware Platforms - OS Releases:
	s700: 10.26

Products: N/A

Filesets:
	OS-Core.CORE-KRN

Automatic Reboot?: Yes

Status: General Superseded

Critical:
	Yes
	PHKL_19002: HANG

Path Name: /hp-ux_patches/s700/10.X/PHKL_19002

Symptoms:
	PHKL_19002:
	Ported 10.20 patch PHKL_18551 to TOS.
	(PHKL_18551)
	( SR: 4701422873 DTS: JAGab11378 )
	Systems that continuously write and truncate a large number
	of files could see CPU consumption increase over time for
	those buffer cache routines that traverse hash link-lists.
	(PHKL_17714)
	( SR: 1653286468 DTS: JAGaa44872 )
	Processes may hang when accessing files in a VxFS file
	system due to a race condition on MP systems between VxFS
	and the buffer cache.
	(PHKL_17624)
	( SR: 5003443622 DTS: JAGaa43921 )
	System appears to hang intermittently due to processes
	being deactivated by the scheduler.
	The symptom is particularly visible on Netscape servers
	or on systems running applications using large amount
	of mmap files.

Defect Description:
	PHKL_19002:
	( SR: 4701422873 DTS: JAGab11378 )
	Buffer cache routines in the kernel are gradually consuming
	more cpu time as buffer hash queues become longer.
	Resolution:
	This problem is resolved by ensuring buffers associated
	with unlinked (or truncated) files are re-used immediately
	ensuring they do not accumulate on any particular link-list.

SR:
	1653286468 4701422873 5003443622

Patch Files:
	/usr/conf/lib/libhp-ux.a(vfs_bio.o)
	/usr/conf/lib/libhp-ux.a(vfs_vm.o)
	/usr/conf/lib/libhp-ux.a(vm_devswap.o)
	/usr/conf/lib/libhp-ux.a(vm_sched.o)
	/usr/conf/lib/libhp-ux.a(vm_swp.o)
	/usr/conf/lib/libhp-ux.a(vm_vhand.o)

what(1) Output:
	/usr/conf/lib/libhp-ux.a(vfs_bio.o):
		99/06/30 kern/sys/vfs_bio.c, hpux, hpux_10.26, ic5db
			 Revision 1.10 PATCH_10.26 (PHKL_19002)
	/usr/conf/lib/libhp-ux.a(vfs_vm.o):
		99/06/30 kern/sys/vfs_vm.c, hpux, hpux_10.26, ic5db
			Revision 1.1 PATCH_10.26 (PHKL_19002) UNMODI
			FIED
	/usr/conf/lib/libhp-ux.a(vm_devswap.o):
		99/06/30 kern/sys/vm_devswap.c, hpux, hpux_10.26, ic
			5db Revision 1.3 PATCH_10.26 (PHKL_19002)
	/usr/conf/lib/libhp-ux.a(vm_sched.o):
		99/06/30 kern/sys/vm_sched.c, hpux, hpux_10.26, ic5d
			b Revision 1.5 PATCH_10.26 (PHKL_19002)
	/usr/conf/lib/libhp-ux.a(vm_swp.o):
		99/06/30 kern/sys/vm_swp.c, hpux, hpux_10.26, ic5db
			Revision 1.1 PATCH_10.26 (PHKL_19002) UNMODI
			FIED
	/usr/conf/lib/libhp-ux.a(vm_vhand.o):
		99/06/30 kern/sys/vm_vhand.c, hpux, hpux_10.26, ic5d
			b Revision 1.1 PATCH_10.26 (PHKL_19002) UNMO
			DIFIED

cksum(1) Output:
	1502362572 31012 /usr/conf/lib/libhp-ux.a(vfs_bio.o)
	3930272690 32924 /usr/conf/lib/libhp-ux.a(vfs_vm.o)
	2065624102 15852 /usr/conf/lib/libhp-ux.a(vm_devswap.o)
	785173996 28480 /usr/conf/lib/libhp-ux.a(vm_sched.o)
	2714554137 8336 /usr/conf/lib/libhp-ux.a(vm_swp.o)
	1376167010 16060 /usr/conf/lib/libhp-ux.a(vm_vhand.o)

Patch Conflicts: None

Patch Dependencies:
	s700: 10.26: PHKL_17282

Hardware Dependencies: None

Other Dependencies: None

Supersedes: None

Equivalent Patches:
	PHKL_19003:
	s800: 10.26

	PHKL_18551:
	s700: 10.20

	PHKL_18552:
	s800: 10.20

Patch Package Size: 190 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_19002

	5a. For a standalone system, run swinstall to install the
	    patch:

		swinstall -x autoreboot=true -x match_target=true \
			-s /tmp/PHKL_19002.depot

	By default swinstall will archive the original software in
	/var/adm/sw/patch/PHKL_19002.  If you do not wish to retain a
	copy of the original software, you can create an empty file
	named /var/adm/sw/patch/PATCH_NOSAVE.

	WARNING: If this file exists when a patch is installed, the
	         patch cannot be deinstalled.  Please be careful
		 when using this feature.

	It is recommended that you move the PHKL_19002.text file to
	/var/adm/sw/patch for future reference.

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

		dd if=/tmp/PHKL_19002.depot of=/dev/rmt/0m bs=2k

Special Installation Instructions:
	This patch depends on base patch PHKL_17282.
	For successful installation, please ensure that PHKL_17282
	is in the same depot with this patch, or PHKL_17282 is
	already installed.