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| author | Janakarajan Natarajan <Janakarajan.Natarajan@amd.com> | 2019-11-05 18:16:55 +0100 |
|---|---|---|
| committer | Shuah Khan <skhan@linuxfoundation.org> | 2019-11-06 01:22:56 +0100 |
| commit | 6af2ed53f0402c09b36d2b38698e18a25ca732a7 (patch) | |
| tree | ea83341eecb9c5b048929e9aa75abf140ae48a3c /virt | |
| parent | cpupower: mperf_monitor: Introduce per_cpu_schedule flag (diff) | |
| download | linux-6af2ed53f0402c09b36d2b38698e18a25ca732a7.tar.xz linux-6af2ed53f0402c09b36d2b38698e18a25ca732a7.zip | |
cpupower: mperf_monitor: Update cpupower to use the RDPRU instruction
AMD Zen 2 introduces the RDPRU instruction which can be used to access some
processor registers which are typically only accessible in privilege level
0. ECX specifies the register to read and EDX:EAX will contain the value read.
ECX: 0 - Register MPERF
1 - Register APERF
This has the added advantage of not having to use the msr module, since the
userspace to kernel transitions which occur during each read_msr() might
cause APERF and MPERF to go out of sync.
Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Acked-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Diffstat (limited to 'virt')
0 files changed, 0 insertions, 0 deletions