vcn_busy_percent(9)

💅 vcn_busy_percent 💅

okay so bestie, welcome to the Kernel API Manual entry for vcn_busy_percent ✨ this one's short and sweet, so let's get into it 🫶

🌸 the whole entire vibe

so the amdgpu driver ships a sysfs API for reading how busy the VCN is as a percentage 👑 that's it, that's the whole point of it. the file you're looking for is called vcn_busy_percent and that's literally the thing you read 💖

and where does the number even come from? the SMU firmware computes a percentage of load based on the aggregate activity level in the IP cores 💅 no cap, that's the source. so like, it's not you doing math, the firmware's got you 🧚

fr fr that percentage is the firmware's own aggregate-activity-level math, so take it as given, not something you compute yourself 🙈

🦋 SEE ALSO 🦋

the kernel file that lives at ./drivers/gpu/drm/amd/pm/amdgpu_pm.c — yes, that exact path, go look at it if you're nosy 💜

and the whole friend group of siblings and cousins, all of them (9), all of them iconic:

• amdgpu_pm_dev_state_check(9)
• amdgpu_pm_get_access(9)
• amdgpu_pm_get_access_if_active(9)
• amdgpu_pm_put_access(9)
• power_dpm_state(9)
• power_dpm_force_performance_level(9)
• pp_table(9)
• pp_od_clk_voltage(9)
• pp_features(9)
• pp_dpm_sclk pp_dpm_mclk pp_dpm_socclk pp_dpm_fclk pp_dpm_dcefclk pp_dpm_pcie(9)
• pp_power_profile_mode(9)
• gpu_busy_percent(9)
• mem_busy_percent(9)
• pcie_bw(9)
• unique_id(9)
• thermal_throttling_logging(9)
• apu_thermal_cap(9)
• gpu_metrics(9)
• smartshift_apu_power(9)
• smartshift_dgpu_power(9)
• smartshift_bias(9)
• board(9)
• baseboard_temp(9)
• gpuboard_temp(9)
• cur_node_power_limit(9)
• node_power(9)
• npm_status(9)
• global_ppt_resid(9)
• max_node_power_limit(9)
• baseboard_power(9)
• baseboard_power_limit(9)
• pm_policy(9)
• hwmon(9)
• fan_curve(9)
• acoustic_limit_rpm_threshold(9)
• acoustic_target_rpm_threshold(9)
• fan_target_temperature(9)
• fan_minimum_pwm(9)
• fan_zero_rpm_enable(9)
• fan_zero_rpm_stop_temperature(9)

iykyk 💀 that's a whole group chat right there, and yes pp_dpm_sclk through pp_dpm_dcefclk are listed bare while pp_dpm_pcie gets the (9) — that's exactly how it's written, don't come for me 🌈

okay bye bestie, go read your percentages 🌸 this little page came from ./drivers/gpu/drm/amd/pm, dated October 2026, and it's filed under vcn_busy_percent(9) — mwah, slay, periodt 💖🎀