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Oracle® X4 Series Servers Administration Guide

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Updated: April 2016
 
 

Configure Elastic Computing (Oracle Solaris Operating System)

Use this procedure to activate or deactivate cores using the Oracle Solaris operating system. You can do this as often as you need, while the application is running.


Note -  If a core is deactivated in BIOS, it cannot be activated in the OS.

Before You Begin

This task requires root privileges.

Elastic computing requires Intel Speed Step, which can be enabled or disabled in the Advanced - CPU Power Management Configuration screen in the BIOS Setup Utility. This setting is enabled by default.

  1. If you do not know the number of the virtual processors associated with the core you wish to deactivate, use the psrinfo -vp command.

    The following sample shows the output on a four-socket server:

    # psrinfo -vp  
    
    The physical processor has 15 cores and 30 virtual processors (0-14 60-74)
      The core has 2 virtual processors (0 60)     Socket 0, core 0, VPs (0, 60) 
      The core has 2 virtual processors (1 61)
      The core has 2 virtual processors (2 62)
      The core has 2 virtual processors (3 63)
      The core has 2 virtual processors (4 64)
      The core has 2 virtual processors (5 65)
      The core has 2 virtual processors (6 66)
      The core has 2 virtual processors (7 67)
      The core has 2 virtual processors (8 68)
      The core has 2 virtual processors (9 69)
      The core has 2 virtual processors (10 70)
      The core has 2 virtual processors (11 71)
      The core has 2 virtual processors (12 72)
      The core has 2 virtual processors (13 73)
      The core has 2 virtual processors (14 74)    Socket 0, core 14, VPs (14, 74)
        x86 (GenuineIntel 306E7 family 6 model 62 step 7 clock 2793 MHz)
          Intel(r) Xeon(r) CPU E7-8895 v2 @ 2.80GHz
    ... To conserve space, physical processors 1 and 2 are not shown here 
    
    The physical processor has 15 cores and 30 virtual processors (45-59 105-119)
      The core has 2 virtual processors (45 105)     Socket 3, core 0, VPs (45, 105)
      The core has 2 virtual processors (46 106)
      The core has 2 virtual processors (47 107)
      The core has 2 virtual processors (48 108)
      The core has 2 virtual processors (49 109)
      The core has 2 virtual processors (50 110)
      The core has 2 virtual processors (51 111)
      The core has 2 virtual processors (52 112)
      The core has 2 virtual processors (53 113)
      The core has 2 virtual processors (54 114)
      The core has 2 virtual processors (55 115)
      The core has 2 virtual processors (56 116)
      The core has 2 virtual processors (57 117)
      The core has 2 virtual processors (58 118)
      The core has 2 virtual processors (59 119)     Socket 3, core 15 VPs (50, 119)
        x86 (GenuineIntel 306E7 family 6 model 62 step 7 clock 2793 MHz)
          Intel(r) Xeon(r) CPU E7-8895 v2 @ 2.80GHz

    To obtain the core number, divide the first virtual processor number by 15.

    • The quotient is the socket number.

    • The remainder is the core number.


    Note -  You can also find the virtual processor and core numbers using the instructions in Calculate Socket and Core Numbers.
  2. To activate or deactivate cores, use the psradm command to activate or deactivate the corresponding virtual processors.
    • To activate cores, use psradm -f to deactivate individual virtual processors.

      To deactivate a core when hyperthreading is enabled, you must deactivate both virtual processors associated with the target core.

      For example:

      psradm -f 59 119 deactivates virtual processors 59 and 119, thereby deactivating core 59.

    • To activate cores and virtual processors, use the psradm -a command.

      Activating either virtual processor associated with a core activates the core.

      psradm -a 59 119 activates both virtual processors associated with core 59.

See Also

Understanding Elastic Computing