cpuidle: fix cpuidle time and usage overflow
Yi Yang [Mon, 25 Feb 2008 00:46:12 +0000 (08:46 +0800)]
cpuidle C-state sysfs node time and usage are very easy to overflow because
they are all of unsigned int type, time will overflow within about two hours,
usage will take longer time to overflow, but they are increasing for ever.

This patch will convert them to unsigned long long.

Signed-off-by: Yi Yang <yi.y.yang@intel.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/cpuidle/cpuidle.c
drivers/cpuidle/sysfs.c
include/linux/cpuidle.h

index d73663a..d42deb3 100644 (file)
@@ -67,7 +67,7 @@ static void cpuidle_idle_call(void)
        /* enter the state and update stats */
        dev->last_residency = target_state->enter(dev, target_state);
        dev->last_state = target_state;
-       target_state->time += dev->last_residency;
+       target_state->time += (unsigned long long)dev->last_residency;
        target_state->usage++;
 
        /* give the governor an opportunity to reflect on the outcome */
index 69102ca..e949618 100644 (file)
@@ -218,6 +218,12 @@ static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
        return sprintf(buf, "%u\n", state->_name);\
 }
 
+#define define_show_state_ull_function(_name) \
+static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
+{ \
+       return sprintf(buf, "%llu\n", state->_name);\
+}
+
 #define define_show_state_str_function(_name) \
 static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
 { \
@@ -228,8 +234,8 @@ static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
 
 define_show_state_function(exit_latency)
 define_show_state_function(power_usage)
-define_show_state_function(usage)
-define_show_state_function(time)
+define_show_state_ull_function(usage)
+define_show_state_ull_function(time)
 define_show_state_str_function(name)
 define_show_state_str_function(desc)
 
index 6b72a45..51e6b1e 100644 (file)
@@ -38,8 +38,8 @@ struct cpuidle_state {
        unsigned int    power_usage; /* in mW */
        unsigned int    target_residency; /* in US */
 
-       unsigned int    usage;
-       unsigned int    time; /* in US */
+       unsigned long long      usage;
+       unsigned long long      time; /* in US */
 
        int (*enter)    (struct cpuidle_device *dev,
                         struct cpuidle_state *state);