Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756641Ab1BAKN3 (ORCPT ); Tue, 1 Feb 2011 05:13:29 -0500 Received: from shutemov.name ([188.40.19.243]:54459 "EHLO shutemov.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751923Ab1BAKNT (ORCPT ); Tue, 1 Feb 2011 05:13:19 -0500 From: "Kirill A. Shutsemov" To: Paul Menage , Li Zefan Cc: containers@lists.linux-foundation.org, jacob.jun.pan@linux.intel.com, Arjan van de Ven , linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCH, v2 2/2] cgroups: introduce timer slack subsystem Date: Tue, 1 Feb 2011 12:13:16 +0200 Message-Id: <1296555196-23088-2-git-send-email-kirill@shutemov.name> X-Mailer: git-send-email 1.7.2.3 In-Reply-To: <1296555196-23088-1-git-send-email-kirill@shutemov.name> References: <1296555196-23088-1-git-send-email-kirill@shutemov.name> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6628 Lines: 226 From: Kirill A. Shutemov Provides a way of tasks grouping by timer slack value. Introduces per cgroup timer slack value which will override the default timer slack value once a task is attached to a cgroup. It's useful in mobile devices where certain background apps are attached to a cgroup and minimum wakeups are desired. Based on patch by Jacob Pan. Signed-off-by: Kirill A. Shutemov --- Changelog: v2: - fixed with CONFIG_CGROUP_TIMER_SLACK=y --- include/linux/cgroup_subsys.h | 6 ++ include/linux/init_task.h | 4 +- init/Kconfig | 10 ++++ kernel/Makefile | 1 + kernel/cgroup_timer_slack.c | 116 +++++++++++++++++++++++++++++++++++++++++ 5 files changed, 136 insertions(+), 1 deletions(-) create mode 100644 kernel/cgroup_timer_slack.c diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h index ccefff0..e399228 100644 --- a/include/linux/cgroup_subsys.h +++ b/include/linux/cgroup_subsys.h @@ -66,3 +66,9 @@ SUBSYS(blkio) #endif /* */ + +#ifdef CONFIG_CGROUP_TIMER_SLACK +SUBSYS(timer_slack) +#endif + +/* */ diff --git a/include/linux/init_task.h b/include/linux/init_task.h index caa151f..48eca8f 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -124,6 +124,8 @@ extern struct cred init_cred; # define INIT_PERF_EVENTS(tsk) #endif +#define TIMER_SLACK_NS_DEFAULT 50000 + /* * INIT_TASK is used to set up the first task table, touch at * your own risk!. Base=0, limit=0x1fffff (=2MB) @@ -177,7 +179,7 @@ extern struct cred init_cred; .cpu_timers = INIT_CPU_TIMERS(tsk.cpu_timers), \ .fs_excl = ATOMIC_INIT(0), \ .pi_lock = __RAW_SPIN_LOCK_UNLOCKED(tsk.pi_lock), \ - .timer_slack_ns = 50000, /* 50 usec default slack */ \ + .timer_slack_ns = TIMER_SLACK_NS_DEFAULT, \ .pids = { \ [PIDTYPE_PID] = INIT_PID_LINK(PIDTYPE_PID), \ [PIDTYPE_PGID] = INIT_PID_LINK(PIDTYPE_PGID), \ diff --git a/init/Kconfig b/init/Kconfig index be788c0..f21b4ce 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -596,6 +596,16 @@ config CGROUP_FREEZER Provides a way to freeze and unfreeze all tasks in a cgroup. +config CGROUP_TIMER_SLACK + tristate "Timer slack cgroup subsystem" + help + Provides a way of tasks grouping by timer slack value. + Introduces per cgroup timer slack value which will override + the default timer slack value once a task is attached to a + cgroup. + It's useful in mobile devices where certain background apps + are attached to a cgroup and minimum wakeups are desired. + config CGROUP_DEVICE bool "Device controller for cgroups" help diff --git a/kernel/Makefile b/kernel/Makefile index 353d3fe..0b60239 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -61,6 +61,7 @@ obj-$(CONFIG_BACKTRACE_SELF_TEST) += backtracetest.o obj-$(CONFIG_COMPAT) += compat.o obj-$(CONFIG_CGROUPS) += cgroup.o obj-$(CONFIG_CGROUP_FREEZER) += cgroup_freezer.o +obj-$(CONFIG_CGROUP_TIMER_SLACK) += cgroup_timer_slack.o obj-$(CONFIG_CPUSETS) += cpuset.o obj-$(CONFIG_CGROUP_NS) += ns_cgroup.o obj-$(CONFIG_UTS_NS) += utsname.o diff --git a/kernel/cgroup_timer_slack.c b/kernel/cgroup_timer_slack.c new file mode 100644 index 0000000..daa452d --- /dev/null +++ b/kernel/cgroup_timer_slack.c @@ -0,0 +1,116 @@ +#include +#include +#include +#include + +struct cgroup_subsys timer_slack_subsys; +struct timer_slack_cgroup { + struct cgroup_subsys_state css; + unsigned long timer_slack_ns; +}; + +static struct timer_slack_cgroup *cgroup_to_tslack_cgroup(struct cgroup *cgroup) +{ + struct cgroup_subsys_state *css; + + css = cgroup_subsys_state(cgroup, timer_slack_subsys.subsys_id); + return container_of(css, struct timer_slack_cgroup, css); +} + +static struct cgroup_subsys_state * +tslack_cgroup_create(struct cgroup_subsys *subsys, struct cgroup *cgroup) +{ + struct timer_slack_cgroup *tslack_cgroup; + struct cgroup *parent = cgroup->parent; + + tslack_cgroup = kmalloc(sizeof(*tslack_cgroup), GFP_KERNEL); + if (!tslack_cgroup) + return ERR_PTR(-ENOMEM); + + if (parent) + tslack_cgroup->timer_slack_ns = + cgroup_to_tslack_cgroup(parent)->timer_slack_ns; + else + tslack_cgroup->timer_slack_ns = TIMER_SLACK_NS_DEFAULT; + + return &tslack_cgroup->css; +} + +static void tslack_cgroup_destroy(struct cgroup_subsys *subsys, + struct cgroup *cgroup) +{ + kfree(cgroup_to_tslack_cgroup(cgroup)); +} + +static void tslack_cgroup_attach(struct cgroup_subsys *subsys, + struct cgroup *cgroup, struct cgroup *prev, + struct task_struct *tsk, bool threadgroup) +{ + struct timer_slack_cgroup *tslack_cgroup; + + tslack_cgroup = cgroup_to_tslack_cgroup(cgroup); + task_lock(tsk); + tsk->timer_slack_ns = tslack_cgroup->timer_slack_ns; + task_unlock(tsk); +} + +static u64 tslack_read_slack_ns(struct cgroup *cgroup, struct cftype *cft) +{ + return cgroup_to_tslack_cgroup(cgroup)->timer_slack_ns; +} + +static int tslack_write_slack_ns(struct cgroup *cgroup, struct cftype *cft, + u64 val) +{ + struct cgroup_iter it; + struct task_struct *task; + + if (!val) + return -EINVAL; + + cgroup_to_tslack_cgroup(cgroup)->timer_slack_ns = val; + + /* change timer slack value for all tasks in the cgroup */ + cgroup_iter_start(cgroup, &it); + while ((task = cgroup_iter_next(cgroup, &it))) + task->timer_slack_ns = val; + cgroup_iter_end(cgroup, &it); + + return 0; +} + +static struct cftype cft_timer_slack = { + .name = "slack_ns", + .read_u64 = tslack_read_slack_ns, + .write_u64 = tslack_write_slack_ns, +}; + +static int tslack_cgroup_populate(struct cgroup_subsys *subsys, + struct cgroup *cgroup) +{ + return cgroup_add_file(cgroup, subsys, &cft_timer_slack); +} + +struct cgroup_subsys timer_slack_subsys = { + .name = "timer_slack", + .module = THIS_MODULE, + .subsys_id = timer_slack_subsys_id, + .create = tslack_cgroup_create, + .destroy = tslack_cgroup_destroy, + .attach = tslack_cgroup_attach, + .populate = tslack_cgroup_populate, +}; + +static int __init init_cgroup_timer_slack(void) +{ + return cgroup_load_subsys(&timer_slack_subsys); +} + +static void __exit exit_cgroup_timer_slack(void) +{ + cgroup_unload_subsys(&timer_slack_subsys); +} + +module_init(init_cgroup_timer_slack); +module_exit(exit_cgroup_timer_slack); +MODULE_LICENSE("GPL"); -- 1.7.3.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/