Simultaneous Multi-threading (SMT)

Simultaneous Multi-threading (SMT) on POWER6

Como consultar si una LPAR tiene el SMT configurado.

# smtctl

This system is SMT capable.

This system supports up to 2 SMT threads per processor.

SMT is currently enabled.

SMT boot mode is not set.

SMT threads are bound to the same virtual processor.

proc0 has 2 SMT threads.

Bind processor 0 is bound with proc0

Bind processor 1 is bound with proc0

Admnistrar SMT:

Flags

       -m off

            This option will set simultaneous multi-threading mode to disabled.

       -m on

            This option will set simultaneous multi-threading mode to enabled.

       -w boot

            This option makes the simultaneous multi-threading mode change effective on next and subsequent reboots if you run the bosboot command     before

            the next system reboot.

       -w now

            This option makes the simultaneous multi-threading mode change immediately but will not persist across reboot. If neither the -w boot or the -w

            now options are specified, then the mode change is made immediately. It will persist across subsequent reboots if you run the bosboot command

            before the next system reboot.

Examples

       1    To enable simultaneous multi-threading for the current boot cycle, enter:

            smtctl -m on -w now

            The system displays a message similar to the following:

            smtctl: SMT is now enabled.

       2    To view the current simultaneous multi-threading mode settings and processor information, enter:

            smtctl

            The system displays a message similar to the following:

            This system is SMT capable.

            SMT is currently enabled.

            SMT boot mode is set to disabled.

            proc0 has 2 SMT threads

            Bind processor 0 is bound with proc0

            Bind processor 1 is bound with proc0

            proc2 has 2 SMT threads

            Bind processor 2 is bound with proc2

            Bind processor 3 is bound with proc2

       3    To disable simultaneous multi-threading for the current boot cycle and for all subsequent boots, enter:

            smtctl -m off

            The system displays a message similar to the following:

            smtctl: SMT is now disabled. It will persist across reboots if

            you run the bosboot command before the next reboot.

            Note: The boot image must be remade with the bosboot command before the next reboot.

Diferencia con POWER7

# smtctl

This system is SMT capable.

This system supports up to 4 SMT threads per processor.

SMT is currently enabled.

SMT boot mode is not set.

SMT threads are bound to the same virtual processor.

proc0 has 4 SMT threads.

Bind processor 0 is bound with proc0

Bind processor 1 is bound with proc0

Bind processor 2 is bound with proc0

Bind processor 3 is bound with proc0

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