Patch Name:  PHKL_10930

Patch Description: s700 10.20 TOC and core dump hang cumulative pach

Creation Date: 97/05/08

Post Date:  97/05/26

Hardware Platforms - OS Releases:
        s700: 10.20

Products: N/A

Filesets:
        OS-Core.CORE-KRN

Automatic Reboot?: Yes

Status: General Superseded

Critical:
        Yes
        PHKL_10930: HANG
        PHKL_8203: HANG

Path Name:  /hp-ux_patches/s700/10.X/PHKL_10930

Symptoms:
        PHKL_10930:
        The system hangs when trying to dump core, as the result
        of a system panic or TOC.  (Normally, it would dump core
        and reboot.)

        PHKL_8203:
        MP system hangs during panic. The LED shows system staying
        at INIT CB0B. Machine needs to be TOC'ed to save the core
        dump.

Defect Description:
        PHKL_10930:
        The hang is due to the system taking a floating point
        exception as the result of a PDC defect.

        PHKL_8203:
        In 10.X, interrupt distribution is implemented to allow
        reassignment of interrupt processors to I/O interfaces
        for workload balancing. The assigned interrupt processor
        for an I/O interface may or may not be the system monarch
        depending on the the number of I/O cards and processors
        available.

        During a panic, if the panic processor is the system
        monarch, it will flush the buffer cache on its way down.
        If the interrupt of the disk it is syncing is serviced by
        one of the other processor(s), the I/O completion interrupt
        will not be received and the ISR will not be called
        because the other processor(s) are TOC'ed at this point.
        Without the ISR to signal biodone(), the biowait() sleeps
        forever.

        The fix is to add a timeout in the panic_boot path to break
        out from the hang in disk sync'ing and continue with the
        reboot.

SR:
        4701353094 5003281469

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

what(1) Output:
        /usr/conf/lib/libhp-ux.a(machdep.o):
                machdep.c $Date: 97/05/02 15:15:35 $ $Revision: 1.12
                        6.98.7 $ PATCH_10.20 (PHKL_10930)

cksum(1) Output:
        4235607596 30184 /usr/conf/lib/libhp-ux.a(machdep.o)

Patch Conflicts: None

Patch Dependencies:  None

Hardware Dependencies:  None

Other Dependencies:  None

Supersedes:
        PHKL_8203

Equivalent Patches: None

Patch Package Size:  90 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_10930

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

                swinstall -x autoreboot=true -x match_target=true \
                        -s /tmp/PHKL_10930.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_10930.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_10930.  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_10930.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_10930.depot of=/dev/rmt/0m bs=2k

Special Installation Instructions:  None