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Message-Id: <1616468359-14513-6-git-send-email-aisheng.dong@nxp.com>
Date: Tue, 23 Mar 2021 10:59:18 +0800
From: Dong Aisheng <aisheng.dong@....com>
To: linux-pm@...r.kernel.org, linux-arm-kernel@...ts.infradead.org
Cc: dongas86@...il.com, kernel@...gutronix.de, shawnguo@...nel.org,
linux-imx@....com, linux-kernel@...r.kernel.org,
myungjoo.ham@...sung.com, kyungmin.park@...sung.com,
cw00.choi@...sung.com, abel.vesa@....com,
Dong Aisheng <aisheng.dong@....com>
Subject: [PATCH V2 5/6] PM / devfreq: governor: optimize simpleondemand get_target_freq
The device profile up_threshold/down_differential 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@....com>
---
Change Log:
v1->v2:
* rebase to devfreq-testing
---
drivers/devfreq/devfreq.c | 24 +++++-------------
drivers/devfreq/governor_simpleondemand.c | 31 +++++++++++++++--------
2 files changed, 26 insertions(+), 29 deletions(-)
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index cacda7d1f858..270e51f5318f 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -1908,9 +1908,7 @@ static ssize_t up_threshold_show(struct device *dev,
if (!df->profile)
return -EINVAL;
- return sprintf(buf, "%d\n", df->profile->up_threshold
- ? df->profile->up_threshold
- : DEVFREQ_UP_THRESHOLD);
+ return sprintf(buf, "%d\n", df->profile->up_threshold);
}
static ssize_t up_threshold_store(struct device *dev,
@@ -1934,9 +1932,7 @@ static ssize_t up_threshold_store(struct device *dev,
if (value > 100)
value = 100;
- down_differential = df->profile->down_differential
- ? df->profile->down_differential
- : DEVFREQ_DOWN_DIFFERENCTIAL;
+ down_differential = df->profile->down_differential;
if (value < down_differential)
value = down_differential;
@@ -1961,9 +1957,7 @@ static ssize_t down_differential_show(struct device *dev,
if (!df->profile)
return -EINVAL;
- return sprintf(buf, "%d\n", df->profile->down_differential
- ? df->profile->down_differential
- : DEVFREQ_DOWN_DIFFERENCTIAL);
+ return sprintf(buf, "%d\n", df->profile->down_differential);
}
static ssize_t down_differential_store(struct device *dev,
@@ -1984,9 +1978,7 @@ static ssize_t down_differential_store(struct device *dev,
if (ret != 1)
return -EINVAL;
- up_threshold = df->profile->up_threshold
- ? df->profile->up_threshold
- : DEVFREQ_UP_THRESHOLD;
+ up_threshold = df->profile->up_threshold;
if (value > up_threshold)
value = up_threshold;
@@ -2113,16 +2105,12 @@ static int devfreq_summary_show(struct seq_file *s, void *data)
polling_ms = 0;
if (IS_SUPPORTED_ATTR(devfreq->governor->attrs, UP_THRESHOLD))
- up_threshold = devfreq->profile->up_threshold
- ? devfreq->profile->up_threshold
- : DEVFREQ_UP_THRESHOLD;
+ up_threshold = devfreq->profile->up_threshold;
else
up_threshold = 0;
if (IS_SUPPORTED_ATTR(devfreq->governor->attrs, DOWN_DIFF))
- down_differential = devfreq->profile->down_differential
- ? devfreq->profile->down_differential
- : DEVFREQ_DOWN_DIFFERENCTIAL;
+ down_differential = devfreq->profile->down_differential;
else
down_differential = 0;
mutex_unlock(&devfreq->lock);
diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c
index 93f6061667d9..3e195b46554a 100644
--- a/drivers/devfreq/governor_simpleondemand.c
+++ b/drivers/devfreq/governor_simpleondemand.c
@@ -18,8 +18,8 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
int err;
struct devfreq_dev_status *stat;
unsigned long long a, b;
- unsigned int dfso_upthreshold = DEVFREQ_UP_THRESHOLD;
- unsigned int dfso_downdifferential = DEVFREQ_DOWN_DIFFERENCTIAL;
+ unsigned int dfso_upthreshold = df->profile->up_threshold;
+ unsigned int dfso_downdifferential = df->profile->down_differential;
err = devfreq_update_stats(df);
if (err)
@@ -27,15 +27,6 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
stat = &df->last_status;
- if (df->profile->up_threshold)
- dfso_upthreshold = df->profile->up_threshold;
- if (df->profile->down_differential)
- dfso_downdifferential = df->profile->down_differential;
-
- 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;
@@ -79,11 +70,29 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
return 0;
}
+static int devfreq_simple_ondemand_check_od(struct devfreq *df)
+{
+ if (!df->profile->up_threshold)
+ df->profile->up_threshold = DEVFREQ_UP_THRESHOLD;
+
+ if (!df->profile->down_differential)
+ df->profile->down_differential = DEVFREQ_DOWN_DIFFERENCTIAL;
+
+ if (df->profile->up_threshold > 100 ||
+ df->profile->up_threshold < df->profile->down_differential)
+ return -EINVAL;
+
+ 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;
+
devfreq_monitor_start(devfreq);
break;
--
2.25.1
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