lkml.org 
[lkml]   [2012]   [Dec]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 11/18] sched: add sched_policy and it's sysfs interface
    Date
    This patch add the power aware scheduler knob into sysfs:

    $cat /sys/devices/system/cpu/sched_policy/available_sched_policy
    performance powersaving balance
    $cat /sys/devices/system/cpu/sched_policy/current_sched_policy
    powersaving

    This means the using sched policy is 'powersaving'.

    User can change the policy by commend 'echo':
    echo performance > /sys/devices/system/cpu/current_sched_policy

    Signed-off-by: Alex Shi <alex.shi@intel.com>
    ---
    Documentation/ABI/testing/sysfs-devices-system-cpu | 24 +++++++
    drivers/base/cpu.c | 2 +
    include/linux/cpu.h | 2 +
    kernel/sched/fair.c | 71 ++++++++++++++++++++
    4 files changed, 99 insertions(+), 0 deletions(-)

    diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
    index 6943133..9c9acbf 100644
    --- a/Documentation/ABI/testing/sysfs-devices-system-cpu
    +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
    @@ -53,6 +53,30 @@ 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_policy/current_sched_policy
    + /sys/devices/system/cpu/sched_policy/available_sched_policy
    +Date: Oct 2012
    +Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
    +Description: CFS scheduler policy showing and setting interface.
    +
    + available_sched_policy shows there are 3 kinds of policy now:
    + performance, balance and powersaving.
    + current_sched_policy shows current scheduler policy. And user
    + can change the policy by writing it.
    +
    + Policy decides that CFS scheduler how to distribute tasks onto
    + which CPU unit when tasks number less than LCPU number in system
    +
    + performance: try to spread tasks onto more CPU sockets,
    + more CPU cores.
    +
    + powersaving: try to shrink tasks onto same core or same CPU
    + until every LCPUs are busy.
    +
    + balance: try to shrink tasks onto same core or same CPU
    + until full powered CPUs are busy. This policy also consider
    + system performance when try to save power.
    +
    What: /sys/devices/system/cpu/cpu#/node
    Date: October 2009
    Contact: Linux memory management mailing list <linux-mm@kvack.org>
    diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
    index 6345294..5f6a573 100644
    --- a/drivers/base/cpu.c
    +++ b/drivers/base/cpu.c
    @@ -330,4 +330,6 @@ void __init cpu_dev_init(void)
    panic("Failed to register CPU subsystem");

    cpu_dev_register_generic();
    +
    + create_sysfs_sched_policy_group(cpu_subsys.dev_root);
    }
    diff --git a/include/linux/cpu.h b/include/linux/cpu.h
    index ce7a074..b2e9265 100644
    --- a/include/linux/cpu.h
    +++ b/include/linux/cpu.h
    @@ -36,6 +36,8 @@ extern void cpu_remove_dev_attr(struct device_attribute *attr);
    extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
    extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);

    +extern int create_sysfs_sched_policy_group(struct device *dev);
    +
    #ifdef CONFIG_HOTPLUG_CPU
    extern void unregister_cpu(struct cpu *cpu);
    extern ssize_t arch_cpu_probe(const char *, size_t);
    diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
    index 2cf8673..1b1deb8 100644
    --- a/kernel/sched/fair.c
    +++ b/kernel/sched/fair.c
    @@ -5871,6 +5871,77 @@ static unsigned int get_rr_interval_fair(struct rq *rq, struct task_struct *task

    /* The default scheduler policy is 'performance'. */
    int __read_mostly sched_policy = SCHED_POLICY_PERFORMANCE;
    +
    +#ifdef CONFIG_SYSFS
    +static ssize_t show_available_sched_policy(struct device *dev,
    + struct device_attribute *attr,
    + char *buf)
    +{
    + return sprintf(buf, "performance balance powersaving\n");
    +}
    +
    +static ssize_t show_current_sched_policy(struct device *dev,
    + struct device_attribute *attr,
    + char *buf)
    +{
    + if (sched_policy == SCHED_POLICY_PERFORMANCE)
    + return sprintf(buf, "performance\n");
    + else if (sched_policy == SCHED_POLICY_POWERSAVING)
    + return sprintf(buf, "powersaving\n");
    + else if (sched_policy == SCHED_POLICY_BALANCE)
    + return sprintf(buf, "balance\n");
    + return 0;
    +}
    +
    +static ssize_t set_sched_policy(struct device *dev,
    + struct device_attribute *attr, const char *buf, size_t count)
    +{
    + unsigned int ret = -EINVAL;
    + char str_policy[16];
    +
    + ret = sscanf(buf, "%15s", str_policy);
    + if (ret != 1)
    + return -EINVAL;
    +
    + if (!strcmp(str_policy, "performance"))
    + sched_policy = SCHED_POLICY_PERFORMANCE;
    + else if (!strcmp(str_policy, "powersaving"))
    + sched_policy = SCHED_POLICY_POWERSAVING;
    + else if (!strcmp(str_policy, "balance"))
    + sched_policy = SCHED_POLICY_BALANCE;
    + else
    + return -EINVAL;
    +
    + return count;
    +}
    +
    +/*
    + * * Sysfs setup bits:
    + * */
    +static DEVICE_ATTR(current_sched_policy, 0644, show_current_sched_policy,
    + set_sched_policy);
    +
    +static DEVICE_ATTR(available_sched_policy, 0444,
    + show_available_sched_policy, NULL);
    +
    +static struct attribute *sched_policy_default_attrs[] = {
    + &dev_attr_current_sched_policy.attr,
    + &dev_attr_available_sched_policy.attr,
    + NULL
    +};
    +static struct attribute_group sched_policy_attr_group = {
    + .attrs = sched_policy_default_attrs,
    + .name = "sched_policy",
    +};
    +
    +int __init create_sysfs_sched_policy_group(struct device *dev)
    +{
    + return sysfs_create_group(&dev->kobj, &sched_policy_attr_group);
    +}
    +#else
    +int __init create_sysfs_sched_policy_group(struct device *dev) {}
    +#endif /* CONFIG_SYSFS */
    +
    /*
    * All the scheduling class methods:
    */
    --
    1.7.5.1


    \
     
     \ /
      Last update: 2012-12-10 11:21    [W:4.280 / U:0.088 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site