Messages in this thread Patch in this message | | | From | Dong Aisheng <> | Subject | [PATCH 09/11] PM / devfreq: governor: optimize simpleondemand get_target_freq | Date | Tue, 9 Mar 2021 20:58:39 +0800 |
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devfreq_simple_ondemand_data only needs to be initialized once when calling devm_devfreq_add_device. It's unnecessary to put the data check logic in the hot path (.get_target_freq()) where it will be called all the time during polling. Instead, we only check and initialize it one time during DEVFREQ_GOV_START.
This also helps check data validability in advance during DEVFREQ_GOV_START rather than checking it later when running .get_target_freq().
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> --- drivers/devfreq/governor_simpleondemand.c | 50 +++++++++++++++-------- 1 file changed, 34 insertions(+), 16 deletions(-)
diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c index ea287b57cbf3..341eb7e9dc04 100644 --- a/drivers/devfreq/governor_simpleondemand.c +++ b/drivers/devfreq/governor_simpleondemand.c @@ -15,15 +15,19 @@ /* Default constants for DevFreq-Simple-Ondemand (DFSO) */ #define DFSO_UPTHRESHOLD (90) #define DFSO_DOWNDIFFERENCTIAL (5) + +static struct devfreq_simple_ondemand_data od_default = { + .upthreshold = DFSO_UPTHRESHOLD, + .downdifferential = DFSO_DOWNDIFFERENCTIAL, +}; + static int devfreq_simple_ondemand_func(struct devfreq *df, unsigned long *freq) { int err; struct devfreq_dev_status *stat; unsigned long long a, b; - unsigned int dfso_upthreshold = DFSO_UPTHRESHOLD; - unsigned int dfso_downdifferential = DFSO_DOWNDIFFERENCTIAL; - struct devfreq_simple_ondemand_data *data = df->data; + struct devfreq_simple_ondemand_data *od = df->data; err = devfreq_update_stats(df); if (err) @@ -31,16 +35,6 @@ static int devfreq_simple_ondemand_func(struct devfreq *df, stat = &df->last_status; - if (data) { - if (data->upthreshold) - dfso_upthreshold = data->upthreshold; - if (data->downdifferential) - dfso_downdifferential = data->downdifferential; - } - if (dfso_upthreshold > 100 || - dfso_upthreshold < dfso_downdifferential) - return -EINVAL; - /* Assume MAX if it is going to be divided by zero */ if (stat->total_time == 0) { *freq = DEVFREQ_MAX_FREQ; @@ -55,7 +49,7 @@ static int devfreq_simple_ondemand_func(struct devfreq *df, /* Set MAX if it's busy enough */ if (stat->busy_time * 100 > - stat->total_time * dfso_upthreshold) { + stat->total_time * od->upthreshold) { *freq = DEVFREQ_MAX_FREQ; return 0; } @@ -68,7 +62,7 @@ static int devfreq_simple_ondemand_func(struct devfreq *df, /* Keep the current frequency */ if (stat->busy_time * 100 > - stat->total_time * (dfso_upthreshold - dfso_downdifferential)) { + stat->total_time * (od->upthreshold - od->downdifferential)) { *freq = stat->current_frequency; return 0; } @@ -78,17 +72,41 @@ static int devfreq_simple_ondemand_func(struct devfreq *df, a *= stat->current_frequency; b = div_u64(a, stat->total_time); b *= 100; - b = div_u64(b, (dfso_upthreshold - dfso_downdifferential / 2)); + b = div_u64(b, (od->upthreshold - od->downdifferential / 2)); *freq = (unsigned long) b; return 0; } +static int devfreq_simple_ondemand_check_od(struct devfreq *devfreq) +{ + struct devfreq_simple_ondemand_data *od = devfreq->data; + + if (od) { + if (!od->upthreshold) + od->upthreshold = DFSO_UPTHRESHOLD; + + if (!od->downdifferential) + od->downdifferential = DFSO_DOWNDIFFERENCTIAL; + + if (od->upthreshold > 100 || + od->upthreshold < od->downdifferential) + return -EINVAL; + } else { + od = &od_default; + } + + return 0; +} + static int devfreq_simple_ondemand_handler(struct devfreq *devfreq, unsigned int event, void *data) { switch (event) { case DEVFREQ_GOV_START: + if (devfreq_simple_ondemand_check_od(devfreq)) + return -EINVAL; + return devfreq_monitor_start(devfreq); case DEVFREQ_GOV_STOP: -- 2.25.1
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