Red Hat Bugzilla – Bug 529071
Fix system-config-date to change date and time together
Last modified: 2018-10-27 09:51:39 EDT
Created attachment 364804 [details] Suggested patch fixing it to change date and time together. Description of problem: When the system time on XEN host is adjusted forward, their threads in their application on XEN host get stuck in the nanosleep call and never return from the call. The XEN VMs works with relative time since boot, so when you change date and time with default independent_clock, the XEN VM time will also change. The problem happens because the clock applet runs 'system-config-date' and when you adjust clock forward, it first changes the date, i.e.: date -s 2009/7/26 and then the time, i.e.: date -s 19:50:00 The first date command is actually changing to: 2009/7/26 00:00:00 which will move VM's time ahead. On the second date command the time is fixed. However, as the VM update time in the virtual timer IRQ handler, there is a chance that some threads get the wrong time scheduling timers far away in the future causing the hang we are seeing. Test package available at: https://brewweb.devel.redhat.com/taskinfo?taskID=1905093 Version-Release number of selected component (if applicable): 1.8.12-4.el5 How reproducible: Often Steps to Reproduce: Forward time using system-config-date and check if the thread is hung. Actual results: The thread inside VM's is stuck on nanosleep() Additional info: There is a small C program that keeps printing periodically so when it stops the problem is reproduced.
Created attachment 364805 [details] nanosleep program.
BTW, that test package in brew has the patch applied. Unfortunately, the customer has not responded for quite some time now but local tests shows the patch has it fixed.
This request was evaluated by Red Hat Product Management for inclusion, but this component is not scheduled to be updated in the current Red Hat Enterprise Linux release. If you would like this request to be reviewed for the next minor release, ask your support representative to set the next rhel-x.y flag to "?".
This request was evaluated by Red Hat Product Management for inclusion in the current release of Red Hat Enterprise Linux. Because the affected component is not scheduled to be updated in the current release, Red Hat is unfortunately unable to address this request at this time. Red Hat invites you to ask your support representative to propose this request, if appropriate and relevant, in the next release of Red Hat Enterprise Linux.
This request was erroneously denied for the current release of Red Hat Enterprise Linux. The error has been fixed and this request has been re-proposed for the current release.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHBA-2011-1490.html