[Linuxppc-users] hardware transactions on power9

[Peter Bergner]

On 7/9/18 4:29 PM, Benjamin Herrenschmidt wrote:
>> Due to POWER9 HW errata, we currently don't support HW Transactional
>> Memory in that mode. We have some support to use TM in a VM but not
>> bare metal.
> 
> Note: Before using such a feature, you should always first check for
> its availability via "hwcap".
> 
> Look for the PPC_FEATURE2_HAS_HTM bit in getauxval(AT_HWCAP2)
> (sys/auxv.h)

The easiest way to check for that is at the shell prompt using:

bergner at pike:~$ LD_SHOW_AUXV=1 /bin/true | grep HWCAP
AT_HWCAP:        true_le archpmu vsx arch_2_06 dfp ic_snoop smt mmu fpu altivec ppc64 ppc32
AT_HWCAP2:       htm-nosc vcrypto tar isel ebb dscr htm arch_2_07


Peter