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| author | Paul E. McKenney <paulmck@kernel.org> | 2026-08-14 15:43:51 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2026-08-14 15:43:51 -0700 |
| commit | 9cc63f8bcd560c760d0b12e15bba8f81c86237cf (patch) | |
| tree | 3b5269b1bcf6714171754946367c51e0590f64da /Documentation/gpu/amdgpu/thermal.rst | |
| download | linux-stable-9cc63f8bcd560c760d0b12e15bba8f81c86237cf.tar.gz linux-stable-9cc63f8bcd560c760d0b12e15bba8f81c86237cf.zip | |
Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEADgrafted
Changes:
Make expedited grace periods expedite normal RCU callbacks
Miscellaneous fixes:
* Improve diagnostic output with character task states.
* Mark accesses to inform KCSAN of concurrency design.
* Move from kmalloc() to kmalloc_obj().
* Documentation updates.
* Improve handling of RCU deferred quiescent states.
* Clean up unused function arguments and structure fields.
* Reduce show_rcu_gp_kthreads() stack space.
Tasks RCU updates:
* Clean up after SRCU re-implementation of Tasks Trace RCU.
* Mark accesses to inform KCSAN of concurrency design.
* Add ->lazy_timer status to diagnostic output.
* Remove an unnecessary memory barrier.
* Fix a data race, courtesy of KCSAN.
* Documentation updates.
* Convert cond_resched_tasks_rcu_qs() from macro to static inline
function.
SRCU updates:
* Add Rust helpers for SRCU.
* Avoid losing queued work at cleanup_srcu_struct() time.
Torture-test updates:
* Preparation work for immediate RCU priority deboosting.
* Test RCU readers from real interrupt handlers (as opposed to softirq).
* Simplify code through use of cpumask_next_wrap().
* Improve diagnostic output with character task states.
* Add rcutorture.nwriters parameter to allow lightweight stall testing,
and rcutorture.stall_only to make doing so easier.
* Test an RCU Tasks Trace grace period implying an RCU grace period.
* Make RCU Tasks Trace torturing track reader batches.
* Fix a data race, courtesy of KCSAN.
* Plug a shuffle_tmp_mask memory leak on kthread spawn failure.
Diffstat (limited to 'Documentation/gpu/amdgpu/thermal.rst')
| -rw-r--r-- | Documentation/gpu/amdgpu/thermal.rst | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/Documentation/gpu/amdgpu/thermal.rst b/Documentation/gpu/amdgpu/thermal.rst new file mode 100644 index 000000000..1768a106a --- /dev/null +++ b/Documentation/gpu/amdgpu/thermal.rst @@ -0,0 +1,170 @@ +=========================================== + GPU Power/Thermal Controls and Monitoring +=========================================== + +HWMON Interfaces +================ + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: hwmon + +GPU sysfs Power State Interfaces +================================ + +GPU power controls are exposed via sysfs files. + +power_dpm_state +--------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: power_dpm_state + +power_dpm_force_performance_level +--------------------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: power_dpm_force_performance_level + +pp_table +-------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: pp_table + +pp_od_clk_voltage +----------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: pp_od_clk_voltage + +pp_dpm_* +-------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: pp_dpm_sclk pp_dpm_mclk pp_dpm_socclk pp_dpm_fclk pp_dpm_dcefclk pp_dpm_pcie + +pp_power_profile_mode +--------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: pp_power_profile_mode + +pm_policy +--------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: pm_policy + +\*_busy_percent +--------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: gpu_busy_percent + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: mem_busy_percent + +gpu_metrics +----------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: gpu_metrics + +fan_curve +--------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: fan_curve + +acoustic_limit_rpm_threshold +---------------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: acoustic_limit_rpm_threshold + +acoustic_target_rpm_threshold +----------------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: acoustic_target_rpm_threshold + +fan_target_temperature +---------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: fan_target_temperature + +fan_minimum_pwm +--------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: fan_minimum_pwm + +fan_zero_rpm_enable +---------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: fan_zero_rpm_enable + +fan_zero_rpm_stop_temperature +----------------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: fan_zero_rpm_stop_temperature + +GFXOFF +====== + +GFXOFF is a feature found in most recent GPUs that saves power at runtime. The +card's RLC (RunList Controller) firmware powers off the gfx engine +dynamically when there is no workload on gfx or compute pipes. GFXOFF is on by +default on supported GPUs. + +Userspace can interact with GFXOFF through a debugfs interface (all values in +`uint32_t`, unless otherwise noted): + +``amdgpu_gfxoff`` +----------------- + +Use it to enable/disable GFXOFF, and to check if it's current enabled/disabled:: + + $ xxd -l1 -p /sys/kernel/debug/dri/0/amdgpu_gfxoff + 01 + +- Write 0 to disable it, and 1 to enable it. +- Read 0 means it's disabled, 1 it's enabled. + +If it's enabled, that means that the GPU is free to enter into GFXOFF mode as +needed. Disabled means that it will never enter GFXOFF mode. + +``amdgpu_gfxoff_status`` +------------------------ + +Read it to check current GFXOFF's status of a GPU:: + + $ xxd -l1 -p /sys/kernel/debug/dri/0/amdgpu_gfxoff_status + 02 + +- 0: GPU is in GFXOFF state, the gfx engine is powered down. +- 1: Transition out of GFXOFF state +- 2: Not in GFXOFF state +- 3: Transition into GFXOFF state + +If GFXOFF is enabled, the value will be transitioning around [0, 3], always +getting into 0 when possible. When it's disabled, it's always at 2. Returns +``-EINVAL`` if it's not supported. + +``amdgpu_gfxoff_count`` +----------------------- + +Read it to get the total GFXOFF entry count at the time of query since system +power-up. The value is an `uint64_t` type, however, due to firmware limitations, +it can currently overflow as an `uint32_t`. *Only supported in vangogh* + +``amdgpu_gfxoff_residency`` +--------------------------- + +Write 1 to amdgpu_gfxoff_residency to start logging, and 0 to stop. Read it to +get average GFXOFF residency % multiplied by 100 during the last logging +interval. E.g. a value of 7854 means 78.54% of the time in the last logging +interval the GPU was in GFXOFF mode. *Only supported in vangogh* |
