2024-12-10 00:17:37 +03:00
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From b1bc26a3ecd5afc4d6106332910fbdc3f6718acd Mon Sep 17 00:00:00 2001
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2024-10-29 05:12:06 +03:00
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From: Swapnil Sapkal <swapnil.sapkal@amd.com>
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Date: Mon, 21 Oct 2024 15:48:36 +0530
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Subject: amd-pstate: Switch to amd-pstate by default on some Server platforms
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Currently the default cpufreq driver for all the AMD EPYC servers is
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acpi-cpufreq. Going forward, switch to amd-pstate as the default
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driver on the AMD EPYC server platforms with CPU family 0x1A or
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higher. The default mode will be active mode.
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Testing shows that amd-pstate with active mode and performance
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governor provides comparable or better performance per-watt against
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acpi-cpufreq + performance governor.
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Likewise, amd-pstate with active mode and powersave governor with the
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energy_performance_preference=power (EPP=255) provides comparable or
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better performance per-watt against acpi-cpufreq + schedutil governor
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for a wide range of workloads.
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Users can still revert to using acpi-cpufreq driver on these platforms
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with the "amd_pstate=disable" kernel commandline parameter.
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Signed-off-by: Swapnil Sapkal <swapnil.sapkal@amd.com>
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Signed-off-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
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Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
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---
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drivers/cpufreq/amd-pstate.c | 4 ++--
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1 file changed, 2 insertions(+), 2 deletions(-)
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--- a/drivers/cpufreq/amd-pstate.c
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+++ b/drivers/cpufreq/amd-pstate.c
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@@ -1862,10 +1862,10 @@ static int __init amd_pstate_init(void)
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if (cppc_state == AMD_PSTATE_UNDEFINED) {
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/* Disable on the following configs by default:
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* 1. Undefined platforms
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- * 2. Server platforms
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+ * 2. Server platforms with CPUs older than Family 0x1A.
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*/
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if (amd_pstate_acpi_pm_profile_undefined() ||
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- amd_pstate_acpi_pm_profile_server()) {
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+ (amd_pstate_acpi_pm_profile_server() && boot_cpu_data.x86 < 0x1A)) {
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pr_info("driver load is disabled, boot with specific mode to enable this\n");
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return -ENODEV;
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}
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