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Recommended update for KERNEL (k_timer)


(Last modified: 02MAY2002)

solutions Recommended update for KERNEL (k_timer) SuSE Linux Maintenance Web (ffa636bf8a54633eab21a2807d3a5364)

Applies to

Product(s): SuSE Linux Enterprise Server 7 for S/390 and zSeries

Package: k_timer
Release: 20020502
Obsoletes: none


This kernel should be installed if you are running many systems in VM/ESA.



Problem description

This update includes IBM patches up to code drop 2002-04-15 (linux-2.4.7-s390-7.tar.gz) as well as some SuSE patches. It fixes the following problems:
  • Hanging processes while simultanious DASD and network I/O. The flag for a disk I/O interrupt accidently gets reset under certain circumstances, leaving the process accessing the disk waiting for a finished I/O transfer.
  • /proc/dasd/devices reports wrong read-only/read-write status for devices that have been modified with the BLKROSET I/O control.
  • System crash in DASD device start because of the bottom half called too early with a request on the block device queue which requeues it to the internal DASD queue even though the device isn't completely initialized yet.
  • DASD devices that are addressed with the DIAG discipline do not work.
  • The IUCV interface does not work after a reboot due to faulty shutdown. The CPU that has brought up the interface must shut it down, which wasn't guaranteed.
  • Late machine check handling because of not setting the check enable bit in the PSW.
  • System either loops or ends with disabled wait when trying to reboot.
  • Device inaccessible after CHPID offline/online cycle.
  • Possible Kernel Oops when writing to /proc/cio_ignore due to off-by-one error in calculation of buffer size.
  • The security fix to prevent a symbolic link DoS reduced the maximum symlink depth from 8 to 5, breaking applications like DB2 that rely on deep linking. The reduction is unnecessary to avoid the DoS.
  • Provides dummy network device as a module.
  • New kernel RPM k_timer which includes the timer patch to reduce load on sites with many linux systems running under VM/ESA. The patch changes the fixed 100 Hz timer interrupt to on-demand timer interrupts.
Additional updates:
  • IBM OCO Drop 2002-03-01 for HiperSocket support. This is available on z/VM 4.2 only and requires the application of the PTFs for the following APARs: VM62938 and VM63034. Please check the VM service information for the the latest available updates: VM Info-APAR II12444 contains useful information for using Linux under VM.


Please install the updates provided at the location noted below.

Installation notes

This update is provided as an RPM package that can easily be installed onto a running system by using these commands:
rpm -Uvh --force k_timer.rpm zipl
Now shut down the Linux system with:
shutdown -h now
(substitute 'now' with an appropriate amount of time if you want to give local users a chance to log out before the Linux system goes down, for example '+10' for 10 minutes.)
After the system has been shut down, re-IPL.

links to download packages

Download Source Packages

Download the source code of the patches for maintained products.


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