From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753929Ab3AXDIz (ORCPT ); Wed, 23 Jan 2013 22:08:55 -0500 Received: from mga01.intel.com ([192.55.52.88]:7626 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753272Ab3AXDHl (ORCPT ); Wed, 23 Jan 2013 22:07:41 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,525,1355126400"; d="scan'208";a="277725041" From: Alex Shi To: torvalds@linux-foundation.org, mingo@redhat.com, peterz@infradead.org, tglx@linutronix.de, akpm@linux-foundation.org, arjan@linux.intel.com, bp@alien8.de, pjt@google.com, namhyung@kernel.org, efault@gmx.de Cc: vincent.guittot@linaro.org, gregkh@linuxfoundation.org, preeti@linux.vnet.ibm.com, viresh.kumar@linaro.org, linux-kernel@vger.kernel.org, alex.shi@intel.com Subject: [patch v4 10/18] sched: add sysfs interface for sched_policy selection Date: Thu, 24 Jan 2013 11:06:52 +0800 Message-Id: <1358996820-23036-11-git-send-email-alex.shi@intel.com> X-Mailer: git-send-email 1.7.12 In-Reply-To: <1358996820-23036-1-git-send-email-alex.shi@intel.com> References: <1358996820-23036-1-git-send-email-alex.shi@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- Documentation/ABI/testing/sysfs-devices-system-cpu | 25 +++++++ kernel/sched/fair.c | 76 ++++++++++++++++++++++ 2 files changed, 101 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 6943133..0ca0727 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -53,6 +53,31 @@ 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 +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. 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 538f469..947542f 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6088,6 +6088,82 @@ 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) +{ + 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); +} + +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: */ -- 1.7.12