It is redundant since commit 7c0ffcd40b16 ("drm/msm/gpu: Respect PM QoS constraints") because dev_pm_qos_update_request triggers get_dev_status.
Signed-off-by: Chia-I Wu olvaffe@gmail.com Cc: Rob Clark robdclark@chromium.org --- drivers/gpu/drm/msm/msm_gpu_devfreq.c | 7 ------- 1 file changed, 7 deletions(-)
diff --git a/drivers/gpu/drm/msm/msm_gpu_devfreq.c b/drivers/gpu/drm/msm/msm_gpu_devfreq.c index 12641616acd3..317a95d42922 100644 --- a/drivers/gpu/drm/msm/msm_gpu_devfreq.c +++ b/drivers/gpu/drm/msm/msm_gpu_devfreq.c @@ -224,7 +224,6 @@ void msm_devfreq_boost(struct msm_gpu *gpu, unsigned factor) void msm_devfreq_active(struct msm_gpu *gpu) { struct msm_gpu_devfreq *df = &gpu->devfreq; - struct devfreq_dev_status status; unsigned int idle_time;
if (!has_devfreq(gpu)) @@ -248,12 +247,6 @@ void msm_devfreq_active(struct msm_gpu *gpu)
dev_pm_qos_update_request(&df->idle_freq, PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE); - - /* - * Reset the polling interval so we aren't inconsistent - * about freq vs busy/total cycles - */ - msm_devfreq_get_dev_status(&gpu->pdev->dev, &status); }
Move tracking and busy time calculation to msm_devfreq_get_dev_status.
Signed-off-by: Chia-I Wu olvaffe@gmail.com Cc: Rob Clark robdclark@chromium.org --- drivers/gpu/drm/msm/adreno/a5xx_gpu.c | 19 ++++++---------- drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 15 +++++-------- drivers/gpu/drm/msm/msm_gpu.h | 9 +++----- drivers/gpu/drm/msm/msm_gpu_devfreq.c | 32 ++++++++++++++++++++++----- 4 files changed, 41 insertions(+), 34 deletions(-)
diff --git a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c index 407f50a15faa..217615e0e850 100644 --- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c +++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c @@ -1662,28 +1662,23 @@ static struct msm_ringbuffer *a5xx_active_ring(struct msm_gpu *gpu) return a5xx_gpu->cur_ring; }
-static unsigned long a5xx_gpu_busy(struct msm_gpu *gpu) +static u64 a5xx_gpu_busy(struct msm_gpu *gpu, unsigned long *out_sample_rate) { - u64 busy_cycles, busy_time; + u64 busy_cycles;
/* Only read the gpu busy if the hardware is already active */ - if (pm_runtime_get_if_in_use(&gpu->pdev->dev) == 0) + if (pm_runtime_get_if_in_use(&gpu->pdev->dev) == 0) { + *out_sample_rate = 1; return 0; + }
busy_cycles = gpu_read64(gpu, REG_A5XX_RBBM_PERFCTR_RBBM_0_LO, REG_A5XX_RBBM_PERFCTR_RBBM_0_HI); - - busy_time = busy_cycles - gpu->devfreq.busy_cycles; - do_div(busy_time, clk_get_rate(gpu->core_clk) / 1000000); - - gpu->devfreq.busy_cycles = busy_cycles; + *out_sample_rate = clk_get_rate(gpu->core_clk);
pm_runtime_put(&gpu->pdev->dev);
- if (WARN_ON(busy_time > ~0LU)) - return ~0LU; - - return (unsigned long)busy_time; + return busy_cycles; }
static uint32_t a5xx_get_rptr(struct msm_gpu *gpu, struct msm_ringbuffer *ring) diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c index ccc4fcf7a630..fba6259395dd 100644 --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c @@ -1649,12 +1649,14 @@ static void a6xx_destroy(struct msm_gpu *gpu) kfree(a6xx_gpu); }
-static unsigned long a6xx_gpu_busy(struct msm_gpu *gpu) +static u64 a6xx_gpu_busy(struct msm_gpu *gpu, unsigned long *out_sample_rate) { struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu); struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu); - u64 busy_cycles, busy_time; + u64 busy_cycles;
+ /* 19.2MHz */ + *out_sample_rate = 19200000;
/* Only read the gpu busy if the hardware is already active */ if (pm_runtime_get_if_in_use(a6xx_gpu->gmu.dev) == 0) @@ -1664,17 +1666,10 @@ static unsigned long a6xx_gpu_busy(struct msm_gpu *gpu) REG_A6XX_GMU_CX_GMU_POWER_COUNTER_XOCLK_0_L, REG_A6XX_GMU_CX_GMU_POWER_COUNTER_XOCLK_0_H);
- busy_time = (busy_cycles - gpu->devfreq.busy_cycles) * 10; - do_div(busy_time, 192); - - gpu->devfreq.busy_cycles = busy_cycles;
pm_runtime_put(a6xx_gpu->gmu.dev);
- if (WARN_ON(busy_time > ~0LU)) - return ~0LU; - - return (unsigned long)busy_time; + return busy_cycles; }
static void a6xx_gpu_set_freq(struct msm_gpu *gpu, struct dev_pm_opp *opp) diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h index 02419f2ca2bc..389c6dab751b 100644 --- a/drivers/gpu/drm/msm/msm_gpu.h +++ b/drivers/gpu/drm/msm/msm_gpu.h @@ -62,7 +62,7 @@ struct msm_gpu_funcs { /* for generation specific debugfs: */ void (*debugfs_init)(struct msm_gpu *gpu, struct drm_minor *minor); #endif - unsigned long (*gpu_busy)(struct msm_gpu *gpu); + u64 (*gpu_busy)(struct msm_gpu *gpu, unsigned long *out_sample_rate); struct msm_gpu_state *(*gpu_state_get)(struct msm_gpu *gpu); int (*gpu_state_put)(struct msm_gpu_state *state); unsigned long (*gpu_get_freq)(struct msm_gpu *gpu); @@ -106,11 +106,8 @@ struct msm_gpu_devfreq { struct dev_pm_qos_request boost_freq;
/** - * busy_cycles: - * - * Used by implementation of gpu->gpu_busy() to track the last - * busy counter value, for calculating elapsed busy cycles since - * last sampling period. + * busy_cycles: Last busy counter value, for calculating elapsed busy + * cycles since last sampling period. */ u64 busy_cycles;
diff --git a/drivers/gpu/drm/msm/msm_gpu_devfreq.c b/drivers/gpu/drm/msm/msm_gpu_devfreq.c index 317a95d42922..f531015107c3 100644 --- a/drivers/gpu/drm/msm/msm_gpu_devfreq.c +++ b/drivers/gpu/drm/msm/msm_gpu_devfreq.c @@ -49,18 +49,38 @@ static unsigned long get_freq(struct msm_gpu *gpu) return clk_get_rate(gpu->core_clk); }
-static int msm_devfreq_get_dev_status(struct device *dev, +static void get_raw_dev_status(struct msm_gpu *gpu, struct devfreq_dev_status *status) { - struct msm_gpu *gpu = dev_to_gpu(dev); + struct msm_gpu_devfreq *df = &gpu->devfreq; + u64 busy_cycles, busy_time; + unsigned long sample_rate; ktime_t time;
status->current_frequency = get_freq(gpu); - status->busy_time = gpu->funcs->gpu_busy(gpu); - + busy_cycles = gpu->funcs->gpu_busy(gpu, &sample_rate); time = ktime_get(); - status->total_time = ktime_us_delta(time, gpu->devfreq.time); - gpu->devfreq.time = time; + + busy_time = busy_cycles - df->busy_cycles; + status->total_time = ktime_us_delta(time, df->time); + + df->busy_cycles = busy_cycles; + df->time = time; + + busy_time *= USEC_PER_SEC; + do_div(busy_time, sample_rate); + if (WARN_ON(busy_time > ~0LU)) + busy_time = ~0LU; + + status->busy_time = busy_time; +} + +static int msm_devfreq_get_dev_status(struct device *dev, + struct devfreq_dev_status *status) +{ + struct msm_gpu *gpu = dev_to_gpu(dev); + + get_raw_dev_status(gpu, status);
return 0; }
simple_ondemand interacts poorly with clamp_to_idle. It only looks at the load since the last get_dev_status call, while it should really look at the load over polling_ms. When clamp_to_idle true, it almost always picks the lowest frequency on active because the gpu is idle between msm_devfreq_idle/msm_devfreq_active.
This logic could potentially be moved into devfreq core.
Fixes: 7c0ffcd40b16 ("drm/msm/gpu: Respect PM QoS constraints") Signed-off-by: Chia-I Wu olvaffe@gmail.com Cc: Rob Clark robdclark@chromium.org --- drivers/gpu/drm/msm/msm_gpu.h | 3 ++ drivers/gpu/drm/msm/msm_gpu_devfreq.c | 60 ++++++++++++++++++++++++++- 2 files changed, 62 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h index 389c6dab751b..143c56f5185b 100644 --- a/drivers/gpu/drm/msm/msm_gpu.h +++ b/drivers/gpu/drm/msm/msm_gpu.h @@ -9,6 +9,7 @@
#include <linux/adreno-smmu-priv.h> #include <linux/clk.h> +#include <linux/devfreq.h> #include <linux/interconnect.h> #include <linux/pm_opp.h> #include <linux/regulator/consumer.h> @@ -117,6 +118,8 @@ struct msm_gpu_devfreq { /** idle_time: Time of last transition to idle: */ ktime_t idle_time;
+ struct devfreq_dev_status average_status; + /** * idle_work: * diff --git a/drivers/gpu/drm/msm/msm_gpu_devfreq.c b/drivers/gpu/drm/msm/msm_gpu_devfreq.c index f531015107c3..d2539ca78c29 100644 --- a/drivers/gpu/drm/msm/msm_gpu_devfreq.c +++ b/drivers/gpu/drm/msm/msm_gpu_devfreq.c @@ -9,6 +9,7 @@
#include <linux/devfreq.h> #include <linux/devfreq_cooling.h> +#include <linux/math64.h> #include <linux/units.h>
/* @@ -75,12 +76,69 @@ static void get_raw_dev_status(struct msm_gpu *gpu, status->busy_time = busy_time; }
+static void update_average_dev_status(struct msm_gpu *gpu, + const struct devfreq_dev_status *raw) +{ + struct msm_gpu_devfreq *df = &gpu->devfreq; + const u32 polling_ms = df->devfreq->profile->polling_ms; + const u32 max_history_ms = polling_ms * 11 / 10; + struct devfreq_dev_status *avg = &df->average_status; + u64 avg_freq; + + /* simple_ondemand governor interacts poorly with gpu->clamp_to_idle. + * When we enforce the constraint on idle, it calls get_dev_status + * which would normally reset the stats. When we remove the + * constraint on active, it calls get_dev_status again where busy_time + * would be 0. + * + * To remedy this, we always return the average load over the past + * polling_ms. + */ + + /* raw is longer than polling_ms or avg has no history */ + if (div_u64(raw->total_time, USEC_PER_MSEC) >= polling_ms || + !avg->total_time) { + *avg = *raw; + return; + } + + /* Truncate the oldest history first. + * + * Because we keep the history with a single devfreq_dev_status, + * rather than a list of devfreq_dev_status, we have to assume freq + * and load are the same over avg->total_time. We can scale down + * avg->busy_time and avg->total_time by the same factor to drop + * history. + */ + if (div_u64(avg->total_time + raw->total_time, USEC_PER_MSEC) >= + max_history_ms) { + const u32 new_total_time = polling_ms * USEC_PER_MSEC - + raw->total_time; + avg->busy_time = div_u64( + mul_u32_u32(avg->busy_time, new_total_time), + avg->total_time); + avg->total_time = new_total_time; + } + + /* compute the average freq over avg->total_time + raw->total_time */ + avg_freq = mul_u32_u32(avg->current_frequency, avg->total_time); + avg_freq += mul_u32_u32(raw->current_frequency, raw->total_time); + do_div(avg_freq, avg->total_time + raw->total_time); + + avg->current_frequency = avg_freq; + avg->busy_time += raw->busy_time; + avg->total_time += raw->total_time; +} + static int msm_devfreq_get_dev_status(struct device *dev, struct devfreq_dev_status *status) { struct msm_gpu *gpu = dev_to_gpu(dev); + struct devfreq_dev_status raw;
- get_raw_dev_status(gpu, status); + get_raw_dev_status(gpu, &raw); + update_average_dev_status(gpu, &raw); + *status = gpu->devfreq.average_status;
return 0; }
On Fri, Apr 15, 2022 at 5:33 PM Chia-I Wu olvaffe@gmail.com wrote:
simple_ondemand interacts poorly with clamp_to_idle. It only looks at the load since the last get_dev_status call, while it should really look at the load over polling_ms. When clamp_to_idle true, it almost always picks the lowest frequency on active because the gpu is idle between msm_devfreq_idle/msm_devfreq_active.
This logic could potentially be moved into devfreq core.
The idea is to extend devfreq_simple_ondemand_data to specify whether devfreq_simple_ondemand_func should use "last status" or "average status" to determine the target frequency. devfreq core will need to store "struct devfreq_dev_status average_status", which will be updated when a device uses simple_ondemand and asks for average_status instead of last_status.
Fixes: 7c0ffcd40b16 ("drm/msm/gpu: Respect PM QoS constraints") Signed-off-by: Chia-I Wu olvaffe@gmail.com Cc: Rob Clark robdclark@chromium.org
drivers/gpu/drm/msm/msm_gpu.h | 3 ++ drivers/gpu/drm/msm/msm_gpu_devfreq.c | 60 ++++++++++++++++++++++++++- 2 files changed, 62 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h index 389c6dab751b..143c56f5185b 100644 --- a/drivers/gpu/drm/msm/msm_gpu.h +++ b/drivers/gpu/drm/msm/msm_gpu.h @@ -9,6 +9,7 @@
#include <linux/adreno-smmu-priv.h> #include <linux/clk.h> +#include <linux/devfreq.h> #include <linux/interconnect.h> #include <linux/pm_opp.h> #include <linux/regulator/consumer.h> @@ -117,6 +118,8 @@ struct msm_gpu_devfreq { /** idle_time: Time of last transition to idle: */ ktime_t idle_time;
struct devfreq_dev_status average_status;/** * idle_work: *diff --git a/drivers/gpu/drm/msm/msm_gpu_devfreq.c b/drivers/gpu/drm/msm/msm_gpu_devfreq.c index f531015107c3..d2539ca78c29 100644 --- a/drivers/gpu/drm/msm/msm_gpu_devfreq.c +++ b/drivers/gpu/drm/msm/msm_gpu_devfreq.c @@ -9,6 +9,7 @@
#include <linux/devfreq.h> #include <linux/devfreq_cooling.h> +#include <linux/math64.h> #include <linux/units.h>
/* @@ -75,12 +76,69 @@ static void get_raw_dev_status(struct msm_gpu *gpu, status->busy_time = busy_time; }
+static void update_average_dev_status(struct msm_gpu *gpu,
const struct devfreq_dev_status *raw)+{
struct msm_gpu_devfreq *df = &gpu->devfreq;const u32 polling_ms = df->devfreq->profile->polling_ms;const u32 max_history_ms = polling_ms * 11 / 10;struct devfreq_dev_status *avg = &df->average_status;u64 avg_freq;/* simple_ondemand governor interacts poorly with gpu->clamp_to_idle.* When we enforce the constraint on idle, it calls get_dev_status* which would normally reset the stats. When we remove the* constraint on active, it calls get_dev_status again where busy_time* would be 0.** To remedy this, we always return the average load over the past* polling_ms.*//* raw is longer than polling_ms or avg has no history */if (div_u64(raw->total_time, USEC_PER_MSEC) >= polling_ms ||!avg->total_time) {*avg = *raw;return;}/* Truncate the oldest history first.** Because we keep the history with a single devfreq_dev_status,* rather than a list of devfreq_dev_status, we have to assume freq* and load are the same over avg->total_time. We can scale down* avg->busy_time and avg->total_time by the same factor to drop* history.*/if (div_u64(avg->total_time + raw->total_time, USEC_PER_MSEC) >=max_history_ms) {const u32 new_total_time = polling_ms * USEC_PER_MSEC -raw->total_time;avg->busy_time = div_u64(mul_u32_u32(avg->busy_time, new_total_time),avg->total_time);avg->total_time = new_total_time;}/* compute the average freq over avg->total_time + raw->total_time */avg_freq = mul_u32_u32(avg->current_frequency, avg->total_time);avg_freq += mul_u32_u32(raw->current_frequency, raw->total_time);do_div(avg_freq, avg->total_time + raw->total_time);avg->current_frequency = avg_freq;avg->busy_time += raw->busy_time;avg->total_time += raw->total_time;+}
static int msm_devfreq_get_dev_status(struct device *dev, struct devfreq_dev_status *status) { struct msm_gpu *gpu = dev_to_gpu(dev);
struct devfreq_dev_status raw;
get_raw_dev_status(gpu, status);
get_raw_dev_status(gpu, &raw);update_average_dev_status(gpu, &raw);*status = gpu->devfreq.average_status; return 0;}
2.36.0.rc0.470.gd361397f0d-goog
dri-devel@lists.freedesktop.org
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Chia-I Wu