Messages in this thread | | | From | Namhyung Kim <> | Subject | Re: [PATCH v3 14/22] sched: add sched_policy and it's sysfs interface | Date | Mon, 14 Jan 2013 15:53:21 +0900 |
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Hi Alex,
Just a few nitpickings..
On Sat, 5 Jan 2013 16:37:43 +0800, Alex Shi wrote: > 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 +++++++ > kernel/sched/fair.c | 76 ++++++++++++++++++++++ > 2 files changed, 100 insertions(+) > > 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/kernel/sched/fair.c b/kernel/sched/fair.c > index f24aca6..ee015b8 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -6102,6 +6102,82 @@ 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)
This line can be combined to the above line.
> +{ > + return sprintf(buf, "performance balance powersaving\n"); > +} > + > +static ssize_t show_current_sched_policy(struct device *dev, > + struct device_attribute *attr, > + char *buf)
Ditto.
> +{ > + 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: > + * */
Unneeded asterisks.
Thanks, Namhyung
> +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); > +} > + > +static int __init sched_policy_sysfs_init(void) > +{ > + return create_sysfs_sched_policy_group(cpu_subsys.dev_root); > +} > + > +core_initcall(sched_policy_sysfs_init); > +#endif /* CONFIG_SYSFS */ > + > /* > * All the scheduling class methods: > */
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