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 24e1ccf229125..aba6d182a7d25 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -709,6 +709,10 @@ __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
