[patch v5 05/15] sched: add sysfs interface for sched_balance_policy selection
This patch add the power aware scheduler knob into sysfs: $cat /sys/devices/system/cpu/sched_balance_policy/available_sched_balance_policy performance powersaving balance $cat /sys/devices/system/cpu/sched_balance_policy/current_sched_balance_policy powersaving This means the using sched balance policy is 'powersaving'. User can change the policy by commend 'echo': echo performance > /sys/devices/system/cpu/sched_balance_policy/current_sched_balance_policy Signed-off-by: Alex Shi --- Documentation/ABI/testing/sysfs-devices-system-cpu | 26 kernel/sched/fair.c| 73 ++ 2 files changed, 99 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 6943133..3283a86 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -53,6 +53,32 @@ Description: Dynamic addition and removal of CPU's. This is not hotplug the system. Information writtento the file to remove CPU's is architecture specific. +What: /sys/devices/system/cpu/sched_balance_policy/current_sched_balance_policy + /sys/devices/system/cpu/sched_balance_policy/available_sched_balance_policy +Date: Oct 2012 +Contact: Linux kernel mailing list +Description: CFS scheduler policy showing and setting interface. + + available_sched_balance_policy shows there are 3 kinds of + policies: + performance, balance and powersaving. + current_sched_balance_policy shows current scheduler policy. + User can change the policy by writing it. + + Policy decides the CFS scheduler how to distribute tasks onto + different CPU unit. + + performance: try to spread tasks onto more CPU sockets, + more CPU cores. performance oriented. + + powersaving: try to pack tasks onto same core or same CPU + until every LCPUs are busy in the core or CPU socket. + powersaving oriented. + + balance: try to pack tasks onto same core or same CPU + until full powered CPUs are busy. + balance between performance and powersaving. + What: /sys/devices/system/cpu/cpu#/node Date: October 2009 Contact: Linux memory management mailing list diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 2f98ffb..fcdb21f 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6108,6 +6108,79 @@ static unsigned int get_rr_interval_fair(struct rq *rq, struct task_struct *task /* The default scheduler policy is 'performance'. */ int __read_mostly sched_balance_policy = SCHED_POLICY_PERFORMANCE; +#ifdef CONFIG_SYSFS +static ssize_t show_available_sched_balance_policy(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "performance balance powersaving\n"); +} + +static ssize_t show_current_sched_balance_policy(struct device *dev, + struct device_attribute *attr, char *buf) +{ + if (sched_balance_policy == SCHED_POLICY_PERFORMANCE) + return sprintf(buf, "performance\n"); + else if (sched_balance_policy == SCHED_POLICY_POWERSAVING) + return sprintf(buf, "powersaving\n"); + else if (sched_balance_policy == SCHED_POLICY_BALANCE) + return sprintf(buf, "balance\n"); + return 0; +} + +static ssize_t set_sched_balance_policy(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + unsigned int ret = -EINVAL; + charstr_policy[16]; + + ret = sscanf(buf, "%15s", str_policy); + if (ret != 1) + return -EINVAL; + + if (!strcmp(str_policy, "performance")) + sched_balance_policy = SCHED_POLICY_PERFORMANCE; + else if (!strcmp(str_policy, "powersaving")) + sched_balance_policy = SCHED_POLICY_POWERSAVING; + else if (!strcmp(str_policy, "balance")) + sched_balance_policy = SCHED_POLICY_BALANCE; + else + return -EINVAL; + + return count; +} + +/* + * * Sysfs setup bits: + * */ +static DEVICE_ATTR(current_sched_balance_policy, 0644, + show_current_sched_balance_policy, set_sched_balance_policy); + +static DEVICE_ATTR(available_sched_balance_policy, 0444, + show_available_sched_balance_policy, NULL); + +static struct attribute *sched_balance_policy_default_attrs[] = { + _attr_current_sched_balance_policy.attr, + _attr_available_sched_balance_policy.attr, + NULL +}; +static struct attribute_group sched_balance_policy_attr_group = { + .attrs = sched_balance_policy_default_attrs, + .name = "sched_balance_policy", +}; + +int
[patch v5 05/15] sched: add sysfs interface for sched_balance_policy selection
This patch add the power aware scheduler knob into sysfs: $cat /sys/devices/system/cpu/sched_balance_policy/available_sched_balance_policy performance powersaving balance $cat /sys/devices/system/cpu/sched_balance_policy/current_sched_balance_policy powersaving This means the using sched balance policy is 'powersaving'. User can change the policy by commend 'echo': echo performance /sys/devices/system/cpu/sched_balance_policy/current_sched_balance_policy Signed-off-by: Alex Shi alex@intel.com --- Documentation/ABI/testing/sysfs-devices-system-cpu | 26 kernel/sched/fair.c| 73 ++ 2 files changed, 99 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 6943133..3283a86 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -53,6 +53,32 @@ Description: Dynamic addition and removal of CPU's. This is not hotplug the system. Information writtento the file to remove CPU's is architecture specific. +What: /sys/devices/system/cpu/sched_balance_policy/current_sched_balance_policy + /sys/devices/system/cpu/sched_balance_policy/available_sched_balance_policy +Date: Oct 2012 +Contact: Linux kernel mailing list linux-kernel@vger.kernel.org +Description: CFS scheduler policy showing and setting interface. + + available_sched_balance_policy shows there are 3 kinds of + policies: + performance, balance and powersaving. + current_sched_balance_policy shows current scheduler policy. + User can change the policy by writing it. + + Policy decides the CFS scheduler how to distribute tasks onto + different CPU unit. + + performance: try to spread tasks onto more CPU sockets, + more CPU cores. performance oriented. + + powersaving: try to pack tasks onto same core or same CPU + until every LCPUs are busy in the core or CPU socket. + powersaving oriented. + + balance: try to pack tasks onto same core or same CPU + until full powered CPUs are busy. + balance between performance and powersaving. + What: /sys/devices/system/cpu/cpu#/node Date: October 2009 Contact: Linux memory management mailing list linux...@kvack.org diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 2f98ffb..fcdb21f 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6108,6 +6108,79 @@ static unsigned int get_rr_interval_fair(struct rq *rq, struct task_struct *task /* The default scheduler policy is 'performance'. */ int __read_mostly sched_balance_policy = SCHED_POLICY_PERFORMANCE; +#ifdef CONFIG_SYSFS +static ssize_t show_available_sched_balance_policy(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, performance balance powersaving\n); +} + +static ssize_t show_current_sched_balance_policy(struct device *dev, + struct device_attribute *attr, char *buf) +{ + if (sched_balance_policy == SCHED_POLICY_PERFORMANCE) + return sprintf(buf, performance\n); + else if (sched_balance_policy == SCHED_POLICY_POWERSAVING) + return sprintf(buf, powersaving\n); + else if (sched_balance_policy == SCHED_POLICY_BALANCE) + return sprintf(buf, balance\n); + return 0; +} + +static ssize_t set_sched_balance_policy(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + unsigned int ret = -EINVAL; + charstr_policy[16]; + + ret = sscanf(buf, %15s, str_policy); + if (ret != 1) + return -EINVAL; + + if (!strcmp(str_policy, performance)) + sched_balance_policy = SCHED_POLICY_PERFORMANCE; + else if (!strcmp(str_policy, powersaving)) + sched_balance_policy = SCHED_POLICY_POWERSAVING; + else if (!strcmp(str_policy, balance)) + sched_balance_policy = SCHED_POLICY_BALANCE; + else + return -EINVAL; + + return count; +} + +/* + * * Sysfs setup bits: + * */ +static DEVICE_ATTR(current_sched_balance_policy, 0644, + show_current_sched_balance_policy, set_sched_balance_policy); + +static DEVICE_ATTR(available_sched_balance_policy, 0444, + show_available_sched_balance_policy, NULL); + +static struct attribute *sched_balance_policy_default_attrs[] = { + dev_attr_current_sched_balance_policy.attr, + dev_attr_available_sched_balance_policy.attr, + NULL +}; +static struct attribute_group sched_balance_policy_attr_group = { + .attrs = sched_balance_policy_default_attrs,