Use this procedure to activate or deactivate cores using the Oracle Solaris operating system (OS). You can do this as often as you need, while the application is running.
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.
The following sample shows the output on a four-socket server:
# psrinfo -vp
The physical processor has 18 cores and 36 virtual processors (0-18 72-89)
continue conversion here...
The core has 2 virtual processors (0 90) Socket 0, core 0, VPs (0, 72)
The core has 2 virtual processors (1 91)
The core has 2 virtual processors (2 92)
The core has 2 virtual processors (3 93)
The core has 2 virtual processors (4 94)
The core has 2 virtual processors (5 95)
The core has 2 virtual processors (6 96)
The core has 2 virtual processors (7 97)
The core has 2 virtual processors (8 98)
The core has 2 virtual processors (9 99)
The core has 2 virtual processors (10 100)
The core has 2 virtual processors (11 101)
The core has 2 virtual processors (12 102)
The core has 2 virtual processors (13 103)
The core has 2 virtual processors (14 104)
The core has 2 virtual processors (15 105)
The core has 2 virtual processors (16 106)
The core has 2 virtual processors (17 107)
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 v3 @ 2.60GHz
... To conserve space, physical processors 1 and 2 are not shown here
The physical processor has 18 cores and 36 virtual processors (72-89 105-119)
The core has 2 virtual processors (72 144) Socket 3, core 0, VPs (72, 144)
The core has 2 virtual processors (73 145)
The core has 2 virtual processors (74 146)
The core has 2 virtual processors (75 147)
The core has 2 virtual processors (76 148)
The core has 2 virtual processors (77 149)
The core has 2 virtual processors (78 150)
The core has 2 virtual processors (79 151)
The core has 2 virtual processors (80 152)
The core has 2 virtual processors (81 153)
The core has 2 virtual processors (82 154)
The core has 2 virtual processors (83 155)
The core has 2 virtual processors (84 156)
The core has 2 virtual processors (85 157)
The core has 2 virtual processors (86 158)
The core has 2 virtual processors (87 159)
The core has 2 virtual processors (88 160)
The core has 2 virtual processors (89 161) Socket 3, core 15 VPs (89, 161)
x86 (GenuineIntel 306E7 family 6 model 62 step 7 clock 2793 MHz)
Intel(r) Xeon(r) CPU E7-8895 v3 @ 2.60GHz
To obtain the core number, divide the first virtual processor number by 18.
The quotient is the socket number.
The remainder is the core number.
To deactivate 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 71 143 deactivates virtual processors 71 and 143, thereby deactivating core 71.
To activate cores and virtual processors, use the psradm -n command.
Activating either virtual processor associated with a core activates the core.
psradm -n 71 143 activates both virtual processors associated with core 71.
See Also