Chapter 20. Red Hat Enterprise Linux 7.5 for IBM Power LE (POWER9)

KVM virtualization is now supported on IBM POWER9 systems. However, due to hardware differences, certain features and functionalities differ from what is supported on AMD64 and Intel 64 systems. For details, see the Virtualization Deployment and Administration Guide.

OProfile now includes support for the IBM POWER9 processor. Note that the PM_RUN_INST_CMPL OProfile performance monitoring event cannot be setup and should not be used in this version of OProfile. (BZ#1463290)

This update adds support for the IBM POWER9 performance monitoring hardware events to papi. It includes basic PAPI presets for events, such as instructions (PAPI_TOT_INS) or processor cycles (PAPI_TOT_CYC). (BZ#1463291)

This version of libpfm includes support for the IBM POWER9 performance monitoring hardware events. (BZ#1463292)

SystemTap includes backported compatibility fixes necessary for the kernel.

Previously, the memcpy() function from the GNU C Library (glibc) used unaligned vector load and store instructions on 64-bit IBM POWER systems. Consequently, when memcpy() was used to access device memory on POWER9 systems, performance would suffer. The memcpy() function has been enhanced to use aligned memory access instructions, to provide better performance for applications regardless of the memory involved on POWER9, without affecting the performance on previous generations of the POWER architecture. (BZ#1498925)