[PATCH 3/4] cgroup: Add new cacheqos cgroup subsys to support Cache QoS Monitoring
Peter P Waskiewicz Jr
peter.p.waskiewicz.jr at intel.com
Fri Jan 3 20:34:44 UTC 2014
This patch adds a new cgroup subsystem, named cacheqos. This cgroup
controller is intended to manage task groups to track cache occupancy
and usage of a CPU.
The cacheqos subsystem operates very similarly to the cpuacct
subsystem. Tasks can be grouped into different child subgroups,
and have separate cache occupancy accounting for each of the
subgroups. See Documentation/cgroups/cacheqos-subsystem.txt for
more details.
The patch also adds the Kconfig option for enabling/disabling the
CGROUP_CACHEQOS subsystem. As this CPU feature is currently found
only in Intel Xeon processors, the cgroup subsystem depends on X86.
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr at intel.com>
---
arch/x86/kernel/cpu/perf_event_intel_uncore.c | 112 ++++++++
include/linux/cgroup_subsys.h | 4 +
include/linux/perf_event.h | 14 +
init/Kconfig | 10 +
kernel/sched/Makefile | 1 +
kernel/sched/cacheqos.c | 397 ++++++++++++++++++++++++++
kernel/sched/cacheqos.h | 59 ++++
7 files changed, 597 insertions(+)
create mode 100644 kernel/sched/cacheqos.c
create mode 100644 kernel/sched/cacheqos.h
diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.c b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
index 29c2487..4d48e26 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
@@ -1633,6 +1633,118 @@ static struct intel_uncore_type *snb_msr_uncores[] = {
};
/* end of Sandy Bridge uncore support */
+#ifdef CONFIG_CGROUP_CACHEQOS
+
+/* needed for the cacheqos cgroup structs */
+#include "../../../kernel/sched/cacheqos.h"
+
+extern struct cacheqos root_cacheqos_group;
+static DEFINE_MUTEX(cqm_mutex);
+
+static int __init cacheqos_late_init(void)
+{
+ struct cpuinfo_x86 *c = &boot_cpu_data;
+ struct rmid_list_element *elem;
+ int i;
+
+ mutex_lock(&cqm_mutex);
+
+ if (cpu_has(c, X86_FEATURE_CQM_OCCUP_LLC)) {
+ root_cacheqos_group.subsys_info =
+ kzalloc(sizeof(struct cacheqos_subsys_info), GFP_KERNEL);
+ if (!root_cacheqos_group.subsys_info) {
+ mutex_unlock(&cqm_mutex);
+ return -ENOMEM;
+ }
+
+ root_cacheqos_group.subsys_info->cache_max_rmid =
+ c->x86_cache_max_rmid;
+ root_cacheqos_group.subsys_info->cache_occ_scale =
+ c->x86_cache_occ_scale;
+ root_cacheqos_group.subsys_info->cache_size = c->x86_cache_size;
+ } else {
+ root_cacheqos_group.monitor_cache = false;
+ root_cacheqos_group.css.ss->disabled = 1;
+ mutex_unlock(&cqm_mutex);
+ return -ENODEV;
+ }
+
+ /* Populate the unused rmid list with all rmids. */
+ INIT_LIST_HEAD(&root_cacheqos_group.subsys_info->rmid_unused_fifo);
+ INIT_LIST_HEAD(&root_cacheqos_group.subsys_info->rmid_inuse_list);
+ elem = kzalloc(sizeof(*elem), GFP_KERNEL);
+ if (!elem)
+ return -ENOMEM;
+
+ elem->rmid = 0;
+ list_add_tail(&elem->list,
+ &root_cacheqos_group.subsys_info->rmid_inuse_list);
+ for (i = 1; i < root_cacheqos_group.subsys_info->cache_max_rmid; i++) {
+ elem = kzalloc(sizeof(*elem), GFP_KERNEL);
+ if (!elem)
+ return -ENOMEM;
+
+ elem->rmid = i;
+ INIT_LIST_HEAD(&elem->list);
+ list_add_tail(&elem->list,
+ &root_cacheqos_group.subsys_info->rmid_unused_fifo);
+ }
+
+ /* go live on the root group */
+ root_cacheqos_group.monitor_cache = true;
+
+ mutex_unlock(&cqm_mutex);
+ return 0;
+}
+late_initcall(cacheqos_late_init);
+
+void cacheqos_map_schedule_out(void)
+{
+ /*
+ * cacheqos_map_schedule_in() will set the MSR correctly, but
+ * clearing the MSR here will prevent occupancy counts against this
+ * task during the context switch. In other words, this gives a
+ * "better" representation of what's happening in the cache.
+ */
+ wrmsrl(IA32_PQR_ASSOC, 0);
+}
+
+void cacheqos_map_schedule_in(struct cacheqos *cq)
+{
+ u64 map;
+
+ map = cq->rmid & IA32_RMID_PQR_MASK;
+ wrmsrl(IA32_PQR_ASSOC, map);
+}
+
+void cacheqos_read(void *arg)
+{
+ struct cacheqos *cq = arg;
+ u64 config;
+ u64 result = 0;
+ int cpu, node;
+
+ cpu = smp_processor_id(),
+ node = cpu_to_node(cpu);
+ config = cq->rmid;
+ config = ((config & IA32_RMID_PQR_MASK) <<
+ IA32_QM_EVTSEL_RMID_POSITION) |
+ IA32_QM_EVTSEL_EVTID_READ_OCC;
+
+ wrmsrl(IA32_QM_EVTSEL, config);
+ rdmsrl(IA32_QM_CTR, result);
+
+ /* place results in sys_wide_info area for recovery */
+ if (result & IA32_QM_CTR_ERR)
+ result = -1;
+ else
+ result &= ~IA32_QM_CTR_ERR;
+
+ cq->subsys_info->node_results[node] =
+ result * cq->subsys_info->cache_occ_scale;
+}
+#endif /* CONFIG_CGROUP_CACHEQOS */
+
/* Nehalem uncore support */
static void nhm_uncore_msr_disable_box(struct intel_uncore_box *box)
{
diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h
index b613ffd..14b97e4 100644
--- a/include/linux/cgroup_subsys.h
+++ b/include/linux/cgroup_subsys.h
@@ -50,6 +50,10 @@ SUBSYS(net_prio)
#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_HUGETLB)
SUBSYS(hugetlb)
#endif
+
+#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_CACHEQOS)
+SUBSYS(cacheqos)
+#endif
/*
* DO NOT ADD ANY SUBSYSTEM WITHOUT EXPLICIT ACKS FROM CGROUP MAINTAINERS.
*/
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 2e069d1..59eabf3 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -54,6 +54,11 @@ struct perf_guest_info_callbacks {
#include <linux/perf_regs.h>
#include <asm/local.h>
+#ifdef CONFIG_CGROUP_CACHEQOS
+inline void cacheqos_sched_out(struct task_struct *task);
+inline void cacheqos_sched_in(struct task_struct *task);
+#endif /* CONFIG_CGROUP_CACHEQOS */
+
struct perf_callchain_entry {
__u64 nr;
__u64 ip[PERF_MAX_STACK_DEPTH];
@@ -676,6 +681,10 @@ static inline void perf_event_task_sched_in(struct task_struct *prev,
{
if (static_key_false(&perf_sched_events.key))
__perf_event_task_sched_in(prev, task);
+
+#ifdef CONFIG_CGROUP_CACHEQOS
+ cacheqos_sched_in(task);
+#endif /* CONFIG_CGROUP_CACHEQOS */
}
static inline void perf_event_task_sched_out(struct task_struct *prev,
@@ -685,6 +694,11 @@ static inline void perf_event_task_sched_out(struct task_struct *prev,
if (static_key_false(&perf_sched_events.key))
__perf_event_task_sched_out(prev, next);
+
+#ifdef CONFIG_CGROUP_CACHEQOS
+ /* use outgoing task to see if cacheqos is active or not */
+ cacheqos_sched_out(prev);
+#endif /* CONFIG_CGROUP_CACHEQOS */
}
extern void perf_event_mmap(struct vm_area_struct *vma);
diff --git a/init/Kconfig b/init/Kconfig
index 4e5d96a..9619cdc 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -905,6 +905,16 @@ config PROC_PID_CPUSET
depends on CPUSETS
default y
+config CGROUP_CACHEQOS
+ bool "Simple Cache QoS Monitoring cgroup subsystem"
+ depends on X86 || X86_64
+ help
+ Provides a simple Resource Controller for monitoring the
+ total cache occupancy by the tasks in a cgroup. This requires
+ hardware support to track cache usage.
+
+ Say N if unsure.
+
config CGROUP_CPUACCT
bool "Simple CPU accounting cgroup subsystem"
help
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index 7b62140..30aa883 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -18,3 +18,4 @@ obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o
obj-$(CONFIG_SCHEDSTATS) += stats.o
obj-$(CONFIG_SCHED_DEBUG) += debug.o
obj-$(CONFIG_CGROUP_CPUACCT) += cpuacct.o
+obj-$(CONFIG_CGROUP_CACHEQOS) += cacheqos.o
diff --git a/kernel/sched/cacheqos.c b/kernel/sched/cacheqos.c
new file mode 100644
index 0000000..1ce799e
--- /dev/null
+++ b/kernel/sched/cacheqos.c
@@ -0,0 +1,397 @@
+#include <linux/cgroup.h>
+#include <linux/slab.h>
+#include <linux/percpu.h>
+#include <linux/spinlock.h>
+#include <linux/cpumask.h>
+#include <linux/seq_file.h>
+#include <linux/rcupdate.h>
+#include <linux/kernel_stat.h>
+#include <linux/err.h>
+
+#include "cacheqos.h"
+#include "sched.h"
+
+struct cacheqos root_cacheqos_group;
+static DEFINE_MUTEX(cacheqos_mutex);
+
+#if !defined(CONFIG_X86_64) || !defined(CONFIG_X86)
+static int __init cacheqos_late_init(void)
+{
+ /* No Cache QoS support on this architecture, disable the subsystem */
+ root_cacheqos_group.monitor_cache = false;
+ root_cacheqos_group.css.ss->disabled = 1;
+ return -ENODEV;
+}
+late_initcall(cacheqos_late_init);
+#endif
+
+inline void cacheqos_sched_out(struct task_struct *task)
+{
+ struct cacheqos *cq = task_cacheqos(task);
+ /*
+ * Assumption is that this thread is running on the logical processor
+ * from which the task is being scheduled out.
+ *
+ * As the task is scheduled out mapping goes back to default map.
+ */
+ if (cq->monitor_cache)
+ cacheqos_map_schedule_out();
+}
+
+inline void cacheqos_sched_in(struct task_struct *task)
+{
+ struct cacheqos *cq = task_cacheqos(task);
+ /*
+ * Assumption is that this thread is running on the logical processor
+ * of which this task is being scheduled onto.
+ *
+ * As the task is scheduled in, the cgroup's rmid is loaded
+ */
+ if (cq->monitor_cache)
+ cacheqos_map_schedule_in(cq);
+}
+
+static void cacheqos_adjust_children_rmid(struct cacheqos *cq)
+{
+ struct cgroup_subsys_state *css, *pos;
+ struct cacheqos *p_cq, *pos_cq;
+
+ css = &cq->css;
+ rcu_read_lock();
+
+ css_for_each_descendant_pre(pos, css) {
+ pos_cq = css_cacheqos(pos);
+ if (!pos_cq->monitor_cache) {
+ /* monitoring is disabled, so use the parent's RMID */
+ p_cq = parent_cacheqos(pos_cq);
+ spin_lock_irq(&pos_cq->lock);
+ pos_cq->rmid = p_cq->rmid;
+ spin_unlock_irq(&pos_cq->lock);
+ }
+ }
+ rcu_read_unlock();
+}
+
+static int cacheqos_move_rmid_to_unused_list(struct cacheqos *cq)
+{
+ struct rmid_list_element *elem;
+
+ /*
+ * Assumes only called when cq->rmid is valid (ie, it is on the
+ * inuse list) and cacheqos_mutex is held.
+ */
+ lockdep_assert_held(&cacheqos_mutex);
+ list_for_each_entry(elem, &cq->subsys_info->rmid_inuse_list, list) {
+ if (cq->rmid == elem->rmid) {
+ /* Move rmid from inuse to unused list */
+ list_del_init(&elem->list);
+ list_add_tail(&elem->list,
+ &cq->subsys_info->rmid_unused_fifo);
+ goto quick_exit;
+ }
+ }
+ return -ELIBBAD;
+
+quick_exit:
+ return 0;
+}
+
+static int cacheqos_deallocate_rmid(struct cacheqos *cq)
+{
+ struct cacheqos *cq_parent = parent_cacheqos(cq);
+ int err;
+
+ mutex_lock(&cacheqos_mutex);
+ err = cacheqos_move_rmid_to_unused_list(cq);
+ if (err)
+ return err;
+ /* assign parent's rmid to cgroup */
+ cq->monitor_cache = false;
+ cq->rmid = cq_parent->rmid;
+
+ /* Check for children using this cgroup's rmid, iterate */
+ cacheqos_adjust_children_rmid(cq);
+
+ mutex_unlock(&cacheqos_mutex);
+ return 0;
+}
+
+static int cacheqos_allocate_rmid(struct cacheqos *cq)
+{
+ struct rmid_list_element *elem;
+ struct list_head *item;
+
+ mutex_lock(&cacheqos_mutex);
+
+ if (list_empty(&cq->subsys_info->rmid_unused_fifo)) {
+ mutex_unlock(&cacheqos_mutex);
+ return -EAGAIN;
+ }
+
+ /* Move rmid from unused to inuse list */
+ item = cq->subsys_info->rmid_unused_fifo.next;
+ list_del_init(item);
+ list_add_tail(item, &cq->subsys_info->rmid_inuse_list);
+
+ /* assign rmid to cgroup */
+ elem = list_entry(item, struct rmid_list_element, list);
+ cq->rmid = elem->rmid;
+ cq->monitor_cache = true;
+
+ /* Check for children using this cgroup's rmid, iterate */
+ cacheqos_adjust_children_rmid(cq);
+
+ mutex_unlock(&cacheqos_mutex);
+
+ return 0;
+}
+
+/* create a new cacheqos cgroup */
+static struct cgroup_subsys_state *
+cacheqos_css_alloc(struct cgroup_subsys_state *parent_css)
+{
+ struct cacheqos *parent = css_cacheqos(parent_css);
+ struct cacheqos *cq;
+
+ if (!parent) {
+ /* cacheqos_late_init() will enable monitoring on the root */
+ root_cacheqos_group.rmid = 0;
+ return &root_cacheqos_group.css;
+ }
+
+ cq = kzalloc(sizeof(struct cacheqos), GFP_KERNEL);
+ if (!cq)
+ goto out;
+
+ cq->cgrp = parent_css->cgroup;
+ cq->monitor_cache = false; /* disabled i.e., use parent's RMID */
+ cq->rmid = parent->rmid; /* Start by using parent's RMID*/
+ cq->subsys_info = root_cacheqos_group.subsys_info;
+ return &cq->css;
+
+out:
+ return ERR_PTR(-ENOMEM);
+}
+
+/* destroy an existing cacheqos task group */
+static void cacheqos_css_free(struct cgroup_subsys_state *css)
+{
+ struct cacheqos *cq = css_cacheqos(css);
+
+ if (cq->monitor_cache) {
+ mutex_lock(&cacheqos_mutex);
+ cacheqos_move_rmid_to_unused_list(cq);
+ mutex_unlock(&cacheqos_mutex);
+ }
+ kfree(cq);
+}
+
+/* return task group's monitoring state */
+static u64 cacheqos_monitor_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ struct cacheqos *cq = css_cacheqos(css);
+
+ return cq->monitor_cache;
+}
+
+/* set the task group's monitoring state */
+static int cacheqos_monitor_write(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 enable)
+{
+ struct cacheqos *cq = css_cacheqos(css);
+ int err = 0;
+
+ if (enable != 0 && enable != 1) {
+ err = -EINVAL;
+ goto monitor_out;
+ }
+
+ if (enable && cq->monitor_cache)
+ goto monitor_out;
+
+ if (cq->monitor_cache)
+ err = cacheqos_deallocate_rmid(cq);
+ else
+ err = cacheqos_allocate_rmid(cq);
+
+monitor_out:
+ return err;
+}
+
+static int cacheqos_get_occupancy_data(struct cacheqos *cq)
+{
+ unsigned int cpu;
+ unsigned int node;
+ const struct cpumask *node_cpus;
+ int err = 0;
+
+ /* Assumes cacheqos_mutex is held */
+ lockdep_assert_held(&cacheqos_mutex);
+ for_each_node_with_cpus(node) {
+ node_cpus = cpumask_of_node(node);
+ cpu = any_online_cpu(*node_cpus);
+ err = smp_call_function_single(cpu, cacheqos_read, cq, 1);
+
+ if (err) {
+ break;
+ } else if (cq->subsys_info->node_results[node] == -1) {
+ err = -EPROTO;
+ break;
+ }
+ }
+ return err;
+}
+
+/* return total system LLC occupancy in bytes of a task group */
+static int cacheqos_occupancy_read(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct seq_file *m)
+{
+ struct cacheqos *cq = css_cacheqos(css);
+ u64 total_occupancy = 0;
+ int err, node;
+
+ mutex_lock(&cacheqos_mutex);
+ err = cacheqos_get_occupancy_data(cq);
+ if (err) {
+ mutex_unlock(&cacheqos_mutex);
+ return err;
+ }
+
+ for_each_node_with_cpus(node)
+ total_occupancy += cq->subsys_info->node_results[node];
+
+ mutex_unlock(&cacheqos_mutex);
+
+ seq_printf(m, "%llu\n", total_occupancy);
+ return 0;
+}
+
+/* return display each LLC's occupancy in bytes of a task group */
+static int
+cacheqos_occupancy_persocket_seq_read(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct seq_file *m)
+{
+ struct cacheqos *cq = css_cacheqos(css);
+ int err, node;
+
+ mutex_lock(&cacheqos_mutex);
+ err = cacheqos_get_occupancy_data(cq);
+ if (err) {
+ mutex_unlock(&cacheqos_mutex);
+ return err;
+ }
+
+ for_each_node_with_cpus(node) {
+ seq_printf(m, "%llu\n",
+ cq->subsys_info->node_results[node]);
+ }
+
+ mutex_unlock(&cacheqos_mutex);
+
+ return 0;
+}
+
+/* return total system LLC occupancy as a %of system LLC for the task group */
+static int cacheqos_occupancy_percent_read(struct cgroup_subsys_state *css,
+ struct cftype *cft,
+ struct seq_file *m)
+{
+ struct cacheqos *cq = css_cacheqos(css);
+ u64 total_occupancy = 0;
+ int err, node;
+ int node_cnt = 0;
+ int parts_of_100, parts_of_10000;
+ int cache_size;
+
+ mutex_lock(&cacheqos_mutex);
+ err = cacheqos_get_occupancy_data(cq);
+ if (err) {
+ mutex_unlock(&cacheqos_mutex);
+ return err;
+ }
+
+ for_each_node_with_cpus(node) {
+ ++node_cnt;
+ total_occupancy += cq->subsys_info->node_results[node];
+ }
+
+ mutex_unlock(&cacheqos_mutex);
+
+ cache_size = cq->subsys_info->cache_size * node_cnt;
+ parts_of_100 = (total_occupancy * 100) / (cache_size * 1024);
+ parts_of_10000 = (total_occupancy * 10000) / (cache_size * 1024) -
+ parts_of_100 * 100;
+ seq_printf(m, "%d.%02d\n", parts_of_100, parts_of_10000);
+
+ return 0;
+}
+
+/* return display each LLC's % occupancy of the socket's LLC for task group */
+static int
+cacheqos_occupancy_percent_persocket_seq_read(struct cgroup_subsys_state *css,
+ struct cftype *cft,
+ struct seq_file *m)
+{
+ struct cacheqos *cq = css_cacheqos(css);
+ u64 total_occupancy;
+ int err, node;
+ int cache_size;
+ int parts_of_100, parts_of_10000;
+
+ mutex_lock(&cacheqos_mutex);
+ err = cacheqos_get_occupancy_data(cq);
+ if (err) {
+ mutex_unlock(&cacheqos_mutex);
+ return err;
+ }
+
+ cache_size = cq->subsys_info->cache_size;
+ for_each_node_with_cpus(node) {
+ total_occupancy = cq->subsys_info->node_results[node];
+ parts_of_100 = (total_occupancy * 100) / (cache_size * 1024);
+ parts_of_10000 = (total_occupancy * 10000) /
+ (cache_size * 1024) - parts_of_100 * 100;
+
+ seq_printf(m, "%d.%02d\n", parts_of_100, parts_of_10000);
+ }
+
+ mutex_unlock(&cacheqos_mutex);
+
+ return 0;
+}
+
+static struct cftype cacheqos_files[] = {
+ {
+ .name = "monitor_cache",
+ .read_u64 = cacheqos_monitor_read,
+ .write_u64 = cacheqos_monitor_write,
+ .mode = 0666,
+ .flags = CFTYPE_NOT_ON_ROOT,
+ },
+ {
+ .name = "occupancy_persocket",
+ .read_seq_string = cacheqos_occupancy_persocket_seq_read,
+ },
+ {
+ .name = "occupancy",
+ .read_seq_string = cacheqos_occupancy_read,
+ },
+ {
+ .name = "occupancy_percent_persocket",
+ .read_seq_string = cacheqos_occupancy_percent_persocket_seq_read,
+ },
+ {
+ .name = "occupancy_percent",
+ .read_seq_string = cacheqos_occupancy_percent_read,
+ },
+ { } /* terminate */
+};
+
+struct cgroup_subsys cacheqos_subsys = {
+ .name = "cacheqos",
+ .css_alloc = cacheqos_css_alloc,
+ .css_free = cacheqos_css_free,
+ .subsys_id = cacheqos_subsys_id,
+ .base_cftypes = cacheqos_files,
+};
diff --git a/kernel/sched/cacheqos.h b/kernel/sched/cacheqos.h
new file mode 100644
index 0000000..b20f25e
--- /dev/null
+++ b/kernel/sched/cacheqos.h
@@ -0,0 +1,59 @@
+#ifndef _CACHEQOS_H_
+#define _CACHEQOS_H_
+#ifdef CONFIG_CGROUP_CACHEQOS
+
+#include <linux/cgroup.h>
+
+struct rmid_list_element {
+ int rmid;
+ struct list_head list;
+};
+
+struct cacheqos_subsys_info {
+ struct list_head rmid_unused_fifo;
+ struct list_head rmid_inuse_list;
+ int cache_max_rmid;
+ int cache_occ_scale;
+ int cache_size;
+ u64 node_results[MAX_NUMNODES];
+};
+
+struct cacheqos {
+ struct cgroup_subsys_state css;
+ struct cacheqos_subsys_info *subsys_info;
+ struct cgroup *cgrp;
+ bool monitor_cache; /* false - use parent RMID / true - new RMID */
+
+ /*
+ * Used for walking the task groups to update RMID's of the various
+ * sub-groups. If monitor_cache is false, the sub-groups will inherit
+ * the parent's RMID. If monitor_cache is true, then the group has its
+ * own RMID.
+ */
+ spinlock_t lock;
+ u32 rmid;
+};
+
+extern void cacheqos_map_schedule_out(void);
+extern void cacheqos_map_schedule_in(struct cacheqos *);
+extern void cacheqos_read(void *);
+
+/* return cacheqos group corresponding to this container */
+static inline struct cacheqos *css_cacheqos(struct cgroup_subsys_state *css)
+{
+ return css ? container_of(css, struct cacheqos, css) : NULL;
+}
+
+/* return cacheqos group to which this task belongs */
+static inline struct cacheqos *task_cacheqos(struct task_struct *task)
+{
+ return css_cacheqos(task_css(task, cacheqos_subsys_id));
+}
+
+static inline struct cacheqos *parent_cacheqos(struct cacheqos *cacheqos)
+{
+ return css_cacheqos(css_parent(&cacheqos->css));
+}
+
+#endif /* CONFIG_CGROUP_CACHEQOS */
+#endif /* _CACHEQOS_H_ */
--
1.8.3.1
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