cpuidle: Change struct menu_device field types

[firefly-linux-kernel-4.4.55.git] / drivers / cpuidle / governors / menu.c

diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index a8b31b0ca57f3b2c8fd0225b4a7489e00d51b98a..cf7f2f0e4ef54d05ee1cc3babeb0555314c894f9 100644 (file)
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -123,10 +123,10 @@ struct menu_device {
        int             needs_update;
 
        unsigned int    expected_us;
-       u64             predicted_us;
+       unsigned int    predicted_us;
        unsigned int    exit_us;
        unsigned int    bucket;
-       u64             correction_factor[BUCKETS];
+       unsigned int    correction_factor[BUCKETS];
        unsigned int    intervals[INTERVALS];
        int             interval_ptr;
 };
@@ -321,8 +321,13 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
        if (data->correction_factor[data->bucket] == 0)
                data->correction_factor[data->bucket] = RESOLUTION * DECAY;
 
-       /* Make sure to round up for half microseconds */
-       data->predicted_us = div_round64(data->expected_us * data->correction_factor[data->bucket],
+       /*
+        * Force the result of multiplication to be 64 bits even if both
+        * operands are 32 bits.
+        * Make sure to round up for half microseconds.
+        */
+       data->predicted_us = div_round64((uint64_t)data->expected_us *
+                                        data->correction_factor[data->bucket],
                                         RESOLUTION * DECAY);
 
        get_typical_interval(data);
@@ -388,7 +393,7 @@ static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
        unsigned int last_idle_us = cpuidle_get_last_residency(dev);
        struct cpuidle_state *target = &drv->states[last_idx];
        unsigned int measured_us;
-       u64 new_factor;
+       unsigned int new_factor;
 
        /*
         * Ugh, this idle state doesn't support residency measurements, so we
@@ -409,10 +414,9 @@ static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
                measured_us -= data->exit_us;
 
 
-       /* update our correction ratio */
-
-       new_factor = data->correction_factor[data->bucket]
-                       * (DECAY - 1) / DECAY;
+       /* Update our correction ratio */
+       new_factor = data->correction_factor[data->bucket];
+       new_factor -= new_factor / DECAY;
 
        if (data->expected_us > 0 && measured_us < MAX_INTERESTING)
                new_factor += RESOLUTION * measured_us / data->expected_us;
@@ -425,9 +429,11 @@ static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 
        /*
         * We don't want 0 as factor; we always want at least
-        * a tiny bit of estimated time.
+        * a tiny bit of estimated time. Fortunately, due to rounding,
+        * new_factor will stay nonzero regardless of measured_us values
+        * and the compiler can eliminate this test as long as DECAY > 1.
         */
-       if (new_factor == 0)
+       if (DECAY == 1 && unlikely(new_factor == 0))
                new_factor = 1;
 
        data->correction_factor[data->bucket] = new_factor;