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authorLinus Torvalds <torvalds@linux-foundation.org>2019-05-09 13:52:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-09 13:52:12 -0700
commitabde77eb5c66b2f98539c4644b54f34b7e179e6b (patch)
treecc6f6142641397e895fba9a19d0971f3827d7422 /include
parent23c970608a0931b913f96f6117ea3e9e1bc06959 (diff)
parentf2b31bb598248c04721cb8485e6091a9feb045ac (diff)
Merge branch 'for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo: "This includes Roman's cgroup2 freezer implementation. It's a separate machanism from cgroup1 freezer. Instead of blocking user tasks in arbitrary uninterruptible sleeps, the new implementation extends jobctl stop - frozen tasks are trapped in jobctl stop until thawed and can be killed and ptraced. Lots of thanks to Oleg for sheperding the effort. Other than that, there are a few trivial changes" * 'for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: never call do_group_exit() with task->frozen bit set kernel: cgroup: fix misuse of %x cgroup: get rid of cgroup_freezer_frozen_exit() cgroup: prevent spurious transition into non-frozen state cgroup: Remove unused cgrp variable cgroup: document cgroup v2 freezer interface cgroup: add tracing points for cgroup v2 freezer cgroup: make TRACE_CGROUP_PATH irq-safe kselftests: cgroup: add freezer controller self-tests kselftests: cgroup: don't fail on cg_kill_all() error in cg_destroy() cgroup: cgroup v2 freezer cgroup: protect cgroup->nr_(dying_)descendants by css_set_lock cgroup: implement __cgroup_task_count() helper cgroup: rename freezer.c into legacy_freezer.c cgroup: remove extra cgroup_migrate_finish() call
Diffstat (limited to 'include')
-rw-r--r--include/linux/cgroup-defs.h33
-rw-r--r--include/linux/cgroup.h43
-rw-r--r--include/linux/sched.h2
-rw-r--r--include/linux/sched/jobctl.h2
-rw-r--r--include/trace/events/cgroup.h55
5 files changed, 135 insertions, 0 deletions
diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h
index 1c70803e9f77..77258d276f93 100644
--- a/include/linux/cgroup-defs.h
+++ b/include/linux/cgroup-defs.h
@@ -65,6 +65,12 @@ enum {
* specified at mount time and thus is implemented here.
*/
CGRP_CPUSET_CLONE_CHILDREN,
+
+ /* Control group has to be frozen. */
+ CGRP_FREEZE,
+
+ /* Cgroup is frozen. */
+ CGRP_FROZEN,
};
/* cgroup_root->flags */
@@ -317,6 +323,25 @@ struct cgroup_rstat_cpu {
struct cgroup *updated_next; /* NULL iff not on the list */
};
+struct cgroup_freezer_state {
+ /* Should the cgroup and its descendants be frozen. */
+ bool freeze;
+
+ /* Should the cgroup actually be frozen? */
+ int e_freeze;
+
+ /* Fields below are protected by css_set_lock */
+
+ /* Number of frozen descendant cgroups */
+ int nr_frozen_descendants;
+
+ /*
+ * Number of tasks, which are counted as frozen:
+ * frozen, SIGSTOPped, and PTRACEd.
+ */
+ int nr_frozen_tasks;
+};
+
struct cgroup {
/* self css with NULL ->ss, points back to this cgroup */
struct cgroup_subsys_state self;
@@ -349,6 +374,11 @@ struct cgroup {
* Dying cgroups are cgroups which were deleted by a user,
* but are still existing because someone else is holding a reference.
* max_descendants is a maximum allowed number of descent cgroups.
+ *
+ * nr_descendants and nr_dying_descendants are protected
+ * by cgroup_mutex and css_set_lock. It's fine to read them holding
+ * any of cgroup_mutex and css_set_lock; for writing both locks
+ * should be held.
*/
int nr_descendants;
int nr_dying_descendants;
@@ -448,6 +478,9 @@ struct cgroup {
/* If there is block congestion on this cgroup. */
atomic_t congestion_count;
+ /* Used to store internal freezer state */
+ struct cgroup_freezer_state freezer;
+
/* ids of the ancestors at each level including self */
int ancestor_ids[];
};
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 81f58b4a5418..c0077adeea83 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -881,4 +881,47 @@ static inline void put_cgroup_ns(struct cgroup_namespace *ns)
free_cgroup_ns(ns);
}
+#ifdef CONFIG_CGROUPS
+
+void cgroup_enter_frozen(void);
+void cgroup_leave_frozen(bool always_leave);
+void cgroup_update_frozen(struct cgroup *cgrp);
+void cgroup_freeze(struct cgroup *cgrp, bool freeze);
+void cgroup_freezer_migrate_task(struct task_struct *task, struct cgroup *src,
+ struct cgroup *dst);
+
+static inline bool cgroup_task_freeze(struct task_struct *task)
+{
+ bool ret;
+
+ if (task->flags & PF_KTHREAD)
+ return false;
+
+ rcu_read_lock();
+ ret = test_bit(CGRP_FREEZE, &task_dfl_cgroup(task)->flags);
+ rcu_read_unlock();
+
+ return ret;
+}
+
+static inline bool cgroup_task_frozen(struct task_struct *task)
+{
+ return task->frozen;
+}
+
+#else /* !CONFIG_CGROUPS */
+
+static inline void cgroup_enter_frozen(void) { }
+static inline void cgroup_leave_frozen(bool always_leave) { }
+static inline bool cgroup_task_freeze(struct task_struct *task)
+{
+ return false;
+}
+static inline bool cgroup_task_frozen(struct task_struct *task)
+{
+ return false;
+}
+
+#endif /* !CONFIG_CGROUPS */
+
#endif /* _LINUX_CGROUP_H */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 50606a6e73d6..a2cd15855bad 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -726,6 +726,8 @@ struct task_struct {
#ifdef CONFIG_CGROUPS
/* disallow userland-initiated cgroup migration */
unsigned no_cgroup_migration:1;
+ /* task is frozen/stopped (used by the cgroup freezer) */
+ unsigned frozen:1;
#endif
#ifdef CONFIG_BLK_CGROUP
/* to be used once the psi infrastructure lands upstream. */
diff --git a/include/linux/sched/jobctl.h b/include/linux/sched/jobctl.h
index 98228bd48aee..fa067de9f1a9 100644
--- a/include/linux/sched/jobctl.h
+++ b/include/linux/sched/jobctl.h
@@ -18,6 +18,7 @@ struct task_struct;
#define JOBCTL_TRAP_NOTIFY_BIT 20 /* trap for NOTIFY */
#define JOBCTL_TRAPPING_BIT 21 /* switching to TRACED */
#define JOBCTL_LISTENING_BIT 22 /* ptracer is listening for events */
+#define JOBCTL_TRAP_FREEZE_BIT 23 /* trap for cgroup freezer */
#define JOBCTL_STOP_DEQUEUED (1UL << JOBCTL_STOP_DEQUEUED_BIT)
#define JOBCTL_STOP_PENDING (1UL << JOBCTL_STOP_PENDING_BIT)
@@ -26,6 +27,7 @@ struct task_struct;
#define JOBCTL_TRAP_NOTIFY (1UL << JOBCTL_TRAP_NOTIFY_BIT)
#define JOBCTL_TRAPPING (1UL << JOBCTL_TRAPPING_BIT)
#define JOBCTL_LISTENING (1UL << JOBCTL_LISTENING_BIT)
+#define JOBCTL_TRAP_FREEZE (1UL << JOBCTL_TRAP_FREEZE_BIT)
#define JOBCTL_TRAP_MASK (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
#define JOBCTL_PENDING_MASK (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
diff --git a/include/trace/events/cgroup.h b/include/trace/events/cgroup.h
index a401ff5e7847..a566cc521476 100644
--- a/include/trace/events/cgroup.h
+++ b/include/trace/events/cgroup.h
@@ -103,6 +103,20 @@ DEFINE_EVENT(cgroup, cgroup_rename,
TP_ARGS(cgrp, path)
);
+DEFINE_EVENT(cgroup, cgroup_freeze,
+
+ TP_PROTO(struct cgroup *cgrp, const char *path),
+
+ TP_ARGS(cgrp, path)
+);
+
+DEFINE_EVENT(cgroup, cgroup_unfreeze,
+
+ TP_PROTO(struct cgroup *cgrp, const char *path),
+
+ TP_ARGS(cgrp, path)
+);
+
DECLARE_EVENT_CLASS(cgroup_migrate,
TP_PROTO(struct cgroup *dst_cgrp, const char *path,
@@ -149,6 +163,47 @@ DEFINE_EVENT(cgroup_migrate, cgroup_transfer_tasks,
TP_ARGS(dst_cgrp, path, task, threadgroup)
);
+DECLARE_EVENT_CLASS(cgroup_event,
+
+ TP_PROTO(struct cgroup *cgrp, const char *path, int val),
+
+ TP_ARGS(cgrp, path, val),
+
+ TP_STRUCT__entry(
+ __field( int, root )
+ __field( int, id )
+ __field( int, level )
+ __string( path, path )
+ __field( int, val )
+ ),
+
+ TP_fast_assign(
+ __entry->root = cgrp->root->hierarchy_id;
+ __entry->id = cgrp->id;
+ __entry->level = cgrp->level;
+ __assign_str(path, path);
+ __entry->val = val;
+ ),
+
+ TP_printk("root=%d id=%d level=%d path=%s val=%d",
+ __entry->root, __entry->id, __entry->level, __get_str(path),
+ __entry->val)
+);
+
+DEFINE_EVENT(cgroup_event, cgroup_notify_populated,
+
+ TP_PROTO(struct cgroup *cgrp, const char *path, int val),
+
+ TP_ARGS(cgrp, path, val)
+);
+
+DEFINE_EVENT(cgroup_event, cgroup_notify_frozen,
+
+ TP_PROTO(struct cgroup *cgrp, const char *path, int val),
+
+ TP_ARGS(cgrp, path, val)
+);
+
#endif /* _TRACE_CGROUP_H */
/* This part must be outside protection */