From b1bc26a3ecd5afc4d6106332910fbdc3f6718acd Mon Sep 17 00:00:00 2001 From: Swapnil Sapkal Date: Mon, 21 Oct 2024 15:48:36 +0530 Subject: amd-pstate: Switch to amd-pstate by default on some Server platforms Currently the default cpufreq driver for all the AMD EPYC servers is acpi-cpufreq. Going forward, switch to amd-pstate as the default driver on the AMD EPYC server platforms with CPU family 0x1A or higher. The default mode will be active mode. Testing shows that amd-pstate with active mode and performance governor provides comparable or better performance per-watt against acpi-cpufreq + performance governor. Likewise, amd-pstate with active mode and powersave governor with the energy_performance_preference=power (EPP=255) provides comparable or better performance per-watt against acpi-cpufreq + schedutil governor for a wide range of workloads. Users can still revert to using acpi-cpufreq driver on these platforms with the "amd_pstate=disable" kernel commandline parameter. Signed-off-by: Swapnil Sapkal Signed-off-by: Gautham R. Shenoy Reviewed-by: Mario Limonciello --- drivers/cpufreq/amd-pstate.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -1862,10 +1862,10 @@ static int __init amd_pstate_init(void) if (cppc_state == AMD_PSTATE_UNDEFINED) { /* Disable on the following configs by default: * 1. Undefined platforms - * 2. Server platforms + * 2. Server platforms with CPUs older than Family 0x1A. */ if (amd_pstate_acpi_pm_profile_undefined() || - amd_pstate_acpi_pm_profile_server()) { + (amd_pstate_acpi_pm_profile_server() && boot_cpu_data.x86 < 0x1A)) { pr_info("driver load is disabled, boot with specific mode to enable this\n"); return -ENODEV; }