Patch Name: PHKL_14218

Patch Description: s700 10.10 mpurge() performance improvement for MP systems

Creation Date: 98/02/17

Post Date:  98/02/20

Hardware Platforms - OS Releases:
	s700: 10.10

Products: N/A

Filesets:
	OS-Core.CORE-KRN

Automatic Reboot?: Yes

Status: General Release

Critical: No

Path Name: /hp-ux_patches/s700/10.X/PHKL_14218

Symptoms:
	PHKL_14218:
	Service Guard time-outs,TOC's and cluster reformation when
	multiple processes call mpurge() simultaneously.

Defect Description:
	PHKL_14218:
	The linear search algorithm to purge the pages associated
	with a vnode is very time consuming.
	In a Service Guard configuration, due to inefficient
	mpurge() code, all the processors (but one) were "spining"
	for the hashlock to the pfdat list while the other
	processor held it. Everyone was trying to do a mpurge.
	This leads to TOC's and cluster reformations as the CPU's
	are not responding to the SG daemon's heartbeat messages.
	The fix was to serialize the access to mpurge() by
	protecting it with an alpha semaphore. The alpha
	semaphore allows a single processor to enter the mpurge
	code. Any other processor will sleep and wait until this
	mpurge either finishes or releases the lock while it
	possibly sleeps in the pageremove() call. This was done to
	allow "service guard" to process its "heartbeat" event.

SR:
	4701380360

Patch Files:
	/usr/conf/lib/libhp-ux.a(sem_utl.o)
	/usr/conf/lib/libhp-ux.a(vm_pgcache.o)

what(1) Output:
	/usr/conf/lib/libhp-ux.a(sem_utl.o):
		sem_utl.c $Date: 98/02/17 15:34:10 $ $Revision: 1.10
			.89.15 $ PATCH_10.10 (PHKL_14218)
	/usr/conf/lib/libhp-ux.a(vm_pgcache.o):
		vm_pgcache.c $Date: 98/02/17 15:23:19 $ $Revision: 1
			.9.89.5 $ PATCH_10.10 (PHKL_14218)

cksum(1) Output:
	3833861326 3416 /usr/conf/lib/libhp-ux.a(sem_utl.o)
	2264985226 7140 /usr/conf/lib/libhp-ux.a(vm_pgcache.o)

Patch Conflicts: None

Patch Dependencies: None

Hardware Dependencies: None

Other Dependencies: None

Supersedes: None

Equivalent Patches:
	PHKL_14219:
	s800: 10.10

Patch Package Size: 70 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_14218

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

		swinstall -x autoreboot=true -x match_target=true \
			-s /tmp/PHKL_14218.depot

	5b. For a homogeneous NFS Diskless cluster run swcluster on the
	    server to install the patch on the server and the clients:

		swcluster -i -b

	    This will invoke swcluster in the interactive mode and
	    force all clients to be shut down.

	    WARNING: All cluster clients must be shut down prior to the
		     patch installation.  Installing the patch while the
		     clients are booted is unsupported and can lead to
		     serious problems.

	    The swcluster command will invoke an swinstall session in which
	    you must specify:

		alternate root path  -  default is /export/shared_root/OS_700
		source depot path    -  /tmp/PHKL_14218.depot

	    To complete the installation, select the patch by choosing
	    "Actions -> Match What Target Has" and then "Actions -> Install"
	    from the Menubar.

	5c. For a heterogeneous NFS Diskless cluster:

		- run swinstall on the server as in step 5a to install
		  the patch on the cluster server.

		- run swcluster on the server as in step 5b to install
		  the patch on the cluster clients.

	By default swinstall will archive the original software in
	/var/adm/sw/patch/PHKL_14218.  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_14218.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_14218.depot of=/dev/rmt/0m bs=2k

Special Installation Instructions: None