From: gcagle@dracula.mentorg.com (Greg Cagle)
Subject: Re: Patch 1065 to the scheduler
Originator: gcagle@dracula.mentorg.com
Date: Wed, 29 Jul 1992 14:46:07 GMT
Organization: Mentor Graphics 
Keywords: 
Followup-To: 


Here is the .text file from PHKL_1065. You can get it from HP (really).

- Greg

Patch Name: PHKL_1065

Patch Description: Fix interactive hangs caused by low memory and swapping.

    Note:  This patch is essentially an 8.07 version of a subset of the 
    virtual memory improvements being made to 9.0 for workstations.

    Problems this patch addresses:

	This patch improves interactive response times while the system is
	heavily paging or swapping, particularly during transient periods
	where the system would run out of physical memory.  However, It
	could either improve or degrade the total time needed to run a
	program while heavily paging.  That is, this patch's intent is to
	improve response time, not throughput, which will likely improve but
	could worsen.

	There are, of course, performance problems in hp-ux, whether related
	to virtual memory or not, which this patch does not address.
	Specific problems addressed are

	- During periods where a process quickly and continually absorbs all
	  free physical memory.  Usually the startup phase of a large
	  process.  Typically, the system appears to hang until the such a
	  period ends.

	- During the swapping of large processes.  Other disk accesses may
	  temporarily be suspended, potentially causing a temporary hang.

	- "nice" has little impact when the system is paging heavily

    How this patch addresses the above problems:

	When "nice" is used to lower the priority of batch processes, this
	patch greatly improves the situations described above, and may
	somewhat improve other performance problems caused by memory stress.
	Even if "nice" is not used, some improvement in interactive response
	will be seen, but using "nice" gives considerably better results.

	The patch includes a new page-out algorithm, a less intrusive
	swapping mechanism, fixes defects causing lockup situations while
	there is no free physical memory, and reduces the chance of the
	system getting in a situation where it has no free physical memory.

	This patch is an early version of some 9.0 improvements for
	interactive performance.

	It would be wise to first run this patch on a trial basis and see if
	your particular performance problems are improved.

Path Name: /hp-ux_patches/s700/8.X/PHKL_1065

Effective Date: 920416

Patch Files: 
/system/PHKL_1065/new/kern_synch.o
/system/PHKL_1065/new/sem_utl.o
/system/PHKL_1065/new/subr_xxx.o
/system/PHKL_1065/new/vfs.o
/system/PHKL_1065/new/vfs_vm.o
/system/PHKL_1065/new/vm_devswap.o
/system/PHKL_1065/new/vm_fault.o
/system/PHKL_1065/new/vm_machdep.o
/system/PHKL_1065/new/vm_misc.o
/system/PHKL_1065/new/vm_page.o
/system/PHKL_1065/new/vm_pregion.o
/system/PHKL_1065/new/vm_sched.o
/system/PHKL_1065/new/vm_swalloc.o
/system/PHKL_1065/new/vm_swp.o
/system/PHKL_1065/new/vm_vhand.o

SR/APR#: I don't know of any.

"what" string/timestamp:
vm_swalloc.o:
	PATCH_8.07:  vm_swalloc.o  1.10.61.6  92/04/13
vm_vhand.o:
	8.07 patch for 9.0 interactive VM improvements (official 4)

"sum" output:
56151 21 kern_synch.o
27355 13 sem_utl.o
39218 33 subr_xxx.o
44294 25 vfs.o
55197 15 vfs_vm.o
5054 22 vm_devswap.o
40881 15 vm_fault.o
30522 79 vm_machdep.o
4069 20 vm_misc.o
9049 23 vm_page.o
16612 20 vm_pregion.o
22685 43 vm_sched.o
49949 37 vm_swalloc.o
11728 12 vm_swp.o
42404 26 vm_vhand.o

Dependencies:  Applies only to 8.07 kernels.  This is also a superset of
	       PHKL_0741 and PHKL_1011, which will break this patch if
	       reapplied after this patch.  If the vfork patch is desired
	       with this one, install vfork first.

Supersedes: PHKL_0616, PHKL_0900.

Patch Package Size: 240Kbytes

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.

     Note: Please back up your system before you patch.

- ---------------------------------------------------------------------------
After getting the patch onto your machine, unshar the patch (sh PHKL_1065).

To install this patch do the following:
1) Run the update program (Note: you must be logged in as root to update
   a system).
2) Once in the update "Main Menu" move the highlighted line to "Change
   Source or Destination ->" and press "Return" or "Select Item".
3) Make sure the highlighted item in the "Change Source or Destination"
   window is "From Tape Device to Local System ...", then press "Return" or
   "Select Item".
4) You should now be in the "From Tape Device to Local System" window.
   Change the "Source:  /dev/rmt/0m" to "Source: /tmp/PHXX_yyyy.updt" 
   (this assumes that you are in the /tmp directory where PHXX_yyyy.updt
   has been placed).  Note: You must enter the complete path name.
5) Press "Done".
6) From here on follow the standard directions for update.

The customized script that update runs will move the original software 
to /system/PHXX_yyyy/orig.  HP recommends keeping this software there in
order to recover from any potential problems.  It is also recommended that
you move the PHXX_yyyy.text file to /system/PHXX_yyyy to be retained for
future reference.

If you wish to put this patch on a magnetic tape and update from the tape
drive, dd a copy of the patch to the tape drive.  As an example the
following will create a copy of the patch that update can read:
dd if=PHXX_yyyy.updt of=/dev/rmt/0m bs=2048
-- 
Greg Cagle               "It's just the same, only different."
Mentor Graphics          
greg_cagle@mentorg.com