OpenVMS ALPDRIV03_071 Alpha V7.1 PUDRIVER ECO Summary

TITLE: OpenVMS ALPDRIV03_071 Alpha V7.1 PUDRIVER ECO Summary
 
NOTE:  An OpenVMS saveset or PCSI installation file is stored
       on the Internet in a self-expanding compressed file.
       The name of the compressed file will be kit_name-dcx_vaxexe
       for OpenVMS VAX or kit_name-dcx_axpexe for OpenVMS Alpha.
 
       Once the file is copied to your system, it can be expanded
       by typing RUN compressed_file.  The resultant file will
       be the OpenVMS saveset or PCSI installation file which
       can be used to install the ECO.
 
*OpenVMS] ALPDRIV03_071 Alpha V7.1 PUDRIVER ECO Summary

Copyright (c) Compaq Computer Corporation 1998.  All rights reserved.

PRODUCT:    OpenVMS Alpha 

COMPONENT:  SYS$PUDRIVER.EXE

SOURCE:     Compaq Computer Corporation

ECO INFORMATION:

     ECO Kit Name:  ALPDRIV03_071
     ECO Kits Superseded by This ECO Kit:  None
     ECO Kit Approximate Size:  252 Blocks
     Kit Applies To:  OpenVMS Alpha V7.1 through V7.1-1H2
     System/Cluster Reboot Necessary:  Yes
     Installation Rating:  2 - To be installed on all systems running
                               the listed version(s) of OpenVMS and
                               using the following feature(s):

                               Any system running OpenVMS V7.1 that
                               uses the PUDRIVER.

     NOTE:  In order to receive the full fixes listed in this kit,
            the following remedial kits also need to be installed:

                 None


ECO KIT SUMMARY:

An ECO kit exists for SYS$PUDRIVER.EXE on OpenVMS Alpha V7.1 through V7.1-1H2.
This kit addresses the following problems: 

  o  A system crash occurs when an attempt is made to place a CDRP 
     into a wait state and the CDRP is already in another incompatible
     wait state.

     The system has no messages available, and some CDRPs have been 
     placed into the message wait queue.  A message response frees a 
     message which is placed in the response ring.  Another message 
     becomes available and the response ring fills up.  A check is
     then made for message waiters.  A waiter is found and a successful
     attempt is made to start it.  An attempt is then made to start
     the next waiter, but there are no more messages so the system
     begins looking for one.  When a message is found, a call is 
     made into the SCS routine to start the first waiter which is the
     waiter that originally started the loop.  Eventually, a return 
     is made to the first waiter which was already started in an 
     inner loop.  The system then either waits or starts the waiter
     again which causes it to be in two states at the same time.

     This problem will only occur with a KCM44 controller because it
     issues the system 45 credits which are enough to exhaust the 
     message queue if a heavy amount of IO is occurring.  


INSTALLATION NOTES:

In order for the corrections in this kit to take effect, the system
must be rebooted.  If the system is a member of a VMScluster, the 
entire cluster should be rebooted. 

Files on this server are as follows:

»alpdriv03_071.README
»alpdriv03_071.CHKSUM
»alpdriv03_071.CVRLET_TXT
»alpdriv03_071.a-dcx_axpexe