Messages in this thread Patch in this message | | | From | Srinivas Pandruvada <> | Subject | [RFC PATCH] thermal/drivers/intel_powerclamp: Support cpumask and step_size | Date | Fri, 27 Jan 2023 12:23:58 -0800 |
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In some use cases, it is desirable to only inject idle on certain set of CPUs. For example on Alder Lake systems, it is possible that we force idle only on P-Cores for thermal reasons. Also the idle percent can be more than 50% if we only choose partial set of CPUs in the system.
Introduce module parameters for setting cpumask and step_size. They can be only changed when the cooling device is inactive. This module already have other module parameters. There is no change done for those parameters.
cpumask (Read/Write): A bit mask of CPUs to inject idle. The format of this bitmask is same as used in other subsystems like in /proc/irq/*/smp_affinity. The mask is comma separated 32 bit groups. Each CPU is one bit. For example for 256 CPU system the full mask is: ffffffff,ffffffff,ffffffff,ffffffff,ffffffff,ffffffff,ffffffff,ffffffff The leftmost mask is for CPU 0-32.
step_size (Read/Write): Step size specifies a multiplication factor to the cooling device state. The step size can be either 1 or 2. By default, step_size = 1. When the step size = 1, the max idle percent is 50%. When step size = 2, the max idle percent is 100%. For the step size of 2, the cpumask should be smaller than the full system cpumask. In this way the system wide idle injection is restricted to 50%.
Since the max state for thermal cooling can't be changed with some thermal core changes, step_size is a way to allow more than 50% idle percent.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> --- .../driver-api/thermal/intel_powerclamp.rst | 22 +++ drivers/thermal/intel/intel_powerclamp.c | 166 ++++++++++++++++-- 2 files changed, 170 insertions(+), 18 deletions(-)
diff --git a/Documentation/driver-api/thermal/intel_powerclamp.rst b/Documentation/driver-api/thermal/intel_powerclamp.rst index 3f6dfb0b3ea6..582e3e42750b 100644 --- a/Documentation/driver-api/thermal/intel_powerclamp.rst +++ b/Documentation/driver-api/thermal/intel_powerclamp.rst @@ -26,6 +26,8 @@ By: - Generic Thermal Layer (sysfs) - Kernel APIs (TBD) + (*) Module Parameters + INTRODUCTION ============ @@ -318,3 +320,23 @@ device, a PID based userspace thermal controller can manage to control CPU temperature effectively, when no other thermal influence is added. For example, a UltraBook user can compile the kernel under certain temperature (below most active trip points). + +Module Parameters +================= + +``cpumask`` (RW) + A bit mask of CPUs to inject idle. The format of the bitmask is same as + used in other subsystems like in /proc/irq/*/smp_affinity. The mask is + comma separated 32 bit groups. Each CPU is one bit. For example for a 256 + CPU system the full mask is: + ffffffff,ffffffff,ffffffff,ffffffff,ffffffff,ffffffff,ffffffff,ffffffff + + The leftmost mask is for CPU 0-32. + +``step_size`` (RW) + Step size specifies a multiplication factor to the cooling device state. + The step size can be either 1 or 2. By default, + step_size = 1. When the step size = 1, the max idle percent is 50%. + When step size = 2, the max idle percent is 100%. For the step size of 2, + the cpumask should be smaller than the full system cpumask. In this way + the system wide idle injection is restricted to 50%. diff --git a/drivers/thermal/intel/intel_powerclamp.c b/drivers/thermal/intel/intel_powerclamp.c index 320525c3c530..221c6de3e06f 100644 --- a/drivers/thermal/intel/intel_powerclamp.c +++ b/drivers/thermal/intel/intel_powerclamp.c @@ -108,6 +108,119 @@ static const struct kernel_param_ops duration_ops = { module_param_cb(duration, &duration_ops, &duration, 0644); MODULE_PARM_DESC(duration, "forced idle time for each attempt in msec."); +static u8 step_size = 1; +static cpumask_var_t idle_injection_cpu_mask; + +static int cpumask_set(const char *arg, const struct kernel_param *kp) +{ + int ret; + + mutex_lock(&powerclamp_lock); + + /* Can't set mask when cooling device is in use */ + if (powerclamp_data.clamping) { + ret = -EAGAIN; + goto skip_cpumask_set; + } + + if (!idle_injection_cpu_mask) { + if (!zalloc_cpumask_var(&idle_injection_cpu_mask, GFP_KERNEL)) { + ret = -ENOMEM; + goto skip_cpumask_set; + } + } + + ret = bitmap_parse(arg, strlen(arg), cpumask_bits(idle_injection_cpu_mask), + nr_cpumask_bits); + if (ret) + goto free_cpu_mask; + + if (cpumask_empty(idle_injection_cpu_mask)) { + ret = -EINVAL; + goto free_cpu_mask; + } + + if (cpumask_equal(cpu_present_mask, idle_injection_cpu_mask) && + step_size > 1) { + ret = -EINVAL; + goto free_cpu_mask; + } + + mutex_unlock(&powerclamp_lock); + + return 0; + +free_cpu_mask: + free_cpumask_var(idle_injection_cpu_mask); + idle_injection_cpu_mask = NULL; + +skip_cpumask_set: + mutex_unlock(&powerclamp_lock); + + return ret; +} + +static int cpumask_get(char *buf, const struct kernel_param *kp) +{ + if (!idle_injection_cpu_mask) + return -EINVAL; + + return bitmap_print_to_pagebuf(false, buf, cpumask_bits(idle_injection_cpu_mask), + nr_cpumask_bits); +} + +static const struct kernel_param_ops cpumask_ops = { + .set = cpumask_set, + .get = cpumask_get, +}; + +module_param_cb(cpumask, &cpumask_ops, NULL, 0644); +MODULE_PARM_DESC(cpumask, "Mask of CPUs to use for idle injection."); + +static int step_size_set(const char *arg, const struct kernel_param *kp) +{ + u8 _step_size; + int ret = 0; + + mutex_lock(&powerclamp_lock); + + /* Can't set mask when cooling device is in use */ + if (powerclamp_data.clamping) { + ret = -EAGAIN; + goto skip_limit_set; + } + + ret = kstrtou8(arg, 10, &_step_size); + if (ret) + goto skip_limit_set; + + if (_step_size > 2) { + ret = -EINVAL; + goto skip_limit_set; + } + + if (idle_injection_cpu_mask && cpumask_equal(cpu_present_mask, idle_injection_cpu_mask) && + _step_size > 1) { + ret = -EINVAL; + goto skip_limit_set; + } + + step_size = _step_size; + +skip_limit_set: + mutex_unlock(&powerclamp_lock); + + return ret; +} + +static const struct kernel_param_ops step_size_ops = { + .set = step_size_set, + .get = param_get_int, +}; + +module_param_cb(step_size, &step_size_ops, &step_size, 0644); +MODULE_PARM_DESC(step_size, "Step size to increment for each cooling state. range 1-2"); + struct powerclamp_calibration_data { unsigned long confidence; /* used for calibration, basically a counter * gets incremented each time a clamping @@ -246,6 +359,9 @@ static unsigned int get_compensation(int ratio) { unsigned int comp = 0; + if (step_size > 1) + return 0; + /* we only use compensation if all adjacent ones are good */ if (ratio == 1 && cal_data[ratio].confidence >= CONFIDENCE_OK && @@ -338,6 +454,10 @@ static unsigned int get_run_time(void) unsigned int compensated_ratio; unsigned int runtime; + /* No compensation for non systemwide idle injection */ + if (step_size > 1) + return (duration * 100 / powerclamp_data.target_ratio - duration); + /* * make sure user selected ratio does not take effect until * the next round. adjust target_ratio if user has changed @@ -454,21 +574,26 @@ static void trigger_idle_injection(void) */ static int powerclamp_idle_injection_register(void) { - /* - * The idle inject core will only inject for online CPUs, - * So we can register for all present CPUs. In this way - * if some CPU goes online/offline while idle inject - * is registered, nothing additional calls are required. - * The same runtime and idle time is applicable for - * newly onlined CPUs if any. - * - * Here cpu_present_mask can be used as is. - * cast to (struct cpumask *) is required as the - * cpu_present_mask is const struct cpumask *, otherwise - * there will be compiler warnings. - */ - ii_dev = idle_inject_register_full((struct cpumask *)cpu_present_mask, - idle_inject_update); + if (!idle_injection_cpu_mask) { + if (!zalloc_cpumask_var(&idle_injection_cpu_mask, GFP_KERNEL)) + return -ENOMEM; + + /* + * The idle inject core will only inject for online CPUs, + * So we can register for all present CPUs. In this way + * if some CPU goes online/offline while idle inject + * is registered, nothing additional calls are required. + * The same runtime and idle time is applicable for + * newly onlined CPUs if any. + */ + cpumask_copy(idle_injection_cpu_mask, cpu_present_mask); + } + + if (cpumask_equal(cpu_present_mask, idle_injection_cpu_mask)) + ii_dev = idle_inject_register_full(idle_injection_cpu_mask, idle_inject_update); + else + ii_dev = idle_inject_register(idle_injection_cpu_mask); + if (!ii_dev) { pr_err("powerclamp: idle_inject_register failed\n"); return -EAGAIN; @@ -504,7 +629,9 @@ static int start_power_clamp(void) ret = powerclamp_idle_injection_register(); if (!ret) { trigger_idle_injection(); - schedule_delayed_work(&poll_pkg_cstate_work, 0); + /* No use of package residency counters when partial set is used */ + if (cpumask_equal(cpu_present_mask, idle_injection_cpu_mask)) + schedule_delayed_work(&poll_pkg_cstate_work, 0); } return ret; @@ -558,7 +685,7 @@ static int powerclamp_set_cur_state(struct thermal_cooling_device *cdev, (unsigned long) (MAX_TARGET_RATIO - 1)); if (!powerclamp_data.target_ratio && new_target_ratio > 0) { pr_info("Start idle injection to reduce power\n"); - powerclamp_data.target_ratio = new_target_ratio; + powerclamp_data.target_ratio = new_target_ratio * step_size; ret = start_power_clamp(); if (ret) powerclamp_data.target_ratio = 0; @@ -570,7 +697,7 @@ static int powerclamp_set_cur_state(struct thermal_cooling_device *cdev, } else /* adjust currently running */ { unsigned int runtime; - powerclamp_data.target_ratio = new_target_ratio; + powerclamp_data.target_ratio = new_target_ratio * step_size; runtime = get_run_time(); idle_inject_set_duration(ii_dev, runtime, duration); } @@ -676,6 +803,9 @@ static void __exit powerclamp_exit(void) cancel_delayed_work_sync(&poll_pkg_cstate_work); debugfs_remove_recursive(debug_dir); + + if (idle_injection_cpu_mask) + free_cpumask_var(idle_injection_cpu_mask); } module_exit(powerclamp_exit); -- 2.37.2
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