From: Perry Yuan <perry.yuan@xxxxxxx> Incorporate a mechanism within the context switching code to reset the hardware history for AMD processors. Specifically, when a task is switched in, the class ID was read and reset the hardware workload classification history of CPU firmware and then it start to trigger workload classification for the next running thread. Signed-off-by: Perry Yuan <perry.yuan@xxxxxxx> Co-developed-by: Mario Limonciello <mario.limonciello@xxxxxxx> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx> --- arch/x86/kernel/process_64.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index f39ff02e498d7..3ceb93b784013 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -707,6 +707,10 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) /* Load the Intel cache allocation PQR MSR. */ resctrl_sched_in(next_p); + /* Reset hw history on AMD CPUs */ + if (cpu_feature_enabled(X86_FEATURE_AMD_WORKLOAD_CLASS)) + wrmsrl(AMD_WORKLOAD_HRST, 0x1); + return prev_p; } -- 2.43.0
