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AIX 5.3 TL12 SP1 CPU suspicious sys time values

  • 1.  AIX 5.3 TL12 SP1 CPU suspicious sys time values

    Posted Fri January 28, 2011 05:18 PM

    Originally posted by: DHKC


    I updated a LPAR on a Power6 560 from AIX 5.3 TL 10 to TL 12 SP1. After rebooting the server, TOPAS_NMON and the mpstat utilities both show all of the virtual processors having a constant sys% time of around 25% even when the user% is zero on the processor. Processor 0 also shows an almost constant utilization of around 75% (25% user + 50% sys) even with just the base AIX processes running (all applications shut down and a single user logged on). The LPAR is using a shared processor pool, is uncapped and SMT is turned on. The LPAR does not appear to be having any problems obtaining extra CPU cycles from the shared pool when needed.

    I have gone back and checked NMON output from before the update was installed and the problem was definitely not evident previously. I have examined the fix list for TL 12 SP2, but did not spot anything related to this problem.

    Has anyone else run into this issue? I have not opened a PMR with IBM yet although that is my next step. Thank you.


  • 2.  Re: AIX 5.3 TL12 SP1 CPU suspicious sys time values

    Posted Sat February 12, 2011 07:14 AM

    Originally posted by: edgging


    Hi,

    I have the same problem on AIX 5.3 TL 12 SP1 and on AIX 6.1 TL5+
    Read this post http://www.ibm.com/developerworks/forums/thread.jspa?threadID=328029

    Regards
    mangod


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