Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge branch 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
"Just one commit from Steven to take out spin lock from trace event
handlers"
* 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup/tracing: Move taking of spin lock out of trace event handlers
+58
-31
+23
-24
include/trace/events/cgroup.h
+23
-24
include/trace/events/cgroup.h
···
53
53
54
54
DECLARE_EVENT_CLASS(cgroup,
55
55
56
-
TP_PROTO(struct cgroup *cgrp),
56
+
TP_PROTO(struct cgroup *cgrp, const char *path),
57
57
58
-
TP_ARGS(cgrp),
58
+
TP_ARGS(cgrp, path),
59
59
60
60
TP_STRUCT__entry(
61
61
__field( int, root )
62
62
__field( int, id )
63
63
__field( int, level )
64
-
__dynamic_array(char, path,
65
-
cgroup_path(cgrp, NULL, 0) + 1)
64
+
__string( path, path )
66
65
),
67
66
68
67
TP_fast_assign(
69
68
__entry->root = cgrp->root->hierarchy_id;
70
69
__entry->id = cgrp->id;
71
70
__entry->level = cgrp->level;
72
-
cgroup_path(cgrp, __get_dynamic_array(path),
73
-
__get_dynamic_array_len(path));
71
+
__assign_str(path, path);
74
72
),
75
73
76
74
TP_printk("root=%d id=%d level=%d path=%s",
···
77
79
78
80
DEFINE_EVENT(cgroup, cgroup_mkdir,
79
81
80
-
TP_PROTO(struct cgroup *cgroup),
82
+
TP_PROTO(struct cgroup *cgrp, const char *path),
81
83
82
-
TP_ARGS(cgroup)
84
+
TP_ARGS(cgrp, path)
83
85
);
84
86
85
87
DEFINE_EVENT(cgroup, cgroup_rmdir,
86
88
87
-
TP_PROTO(struct cgroup *cgroup),
89
+
TP_PROTO(struct cgroup *cgrp, const char *path),
88
90
89
-
TP_ARGS(cgroup)
91
+
TP_ARGS(cgrp, path)
90
92
);
91
93
92
94
DEFINE_EVENT(cgroup, cgroup_release,
93
95
94
-
TP_PROTO(struct cgroup *cgroup),
96
+
TP_PROTO(struct cgroup *cgrp, const char *path),
95
97
96
-
TP_ARGS(cgroup)
98
+
TP_ARGS(cgrp, path)
97
99
);
98
100
99
101
DEFINE_EVENT(cgroup, cgroup_rename,
100
102
101
-
TP_PROTO(struct cgroup *cgroup),
103
+
TP_PROTO(struct cgroup *cgrp, const char *path),
102
104
103
-
TP_ARGS(cgroup)
105
+
TP_ARGS(cgrp, path)
104
106
);
105
107
106
108
DECLARE_EVENT_CLASS(cgroup_migrate,
107
109
108
-
TP_PROTO(struct cgroup *dst_cgrp, struct task_struct *task, bool threadgroup),
110
+
TP_PROTO(struct cgroup *dst_cgrp, const char *path,
111
+
struct task_struct *task, bool threadgroup),
109
112
110
-
TP_ARGS(dst_cgrp, task, threadgroup),
113
+
TP_ARGS(dst_cgrp, path, task, threadgroup),
111
114
112
115
TP_STRUCT__entry(
113
116
__field( int, dst_root )
114
117
__field( int, dst_id )
115
118
__field( int, dst_level )
116
-
__dynamic_array(char, dst_path,
117
-
cgroup_path(dst_cgrp, NULL, 0) + 1)
118
119
__field( int, pid )
120
+
__string( dst_path, path )
119
121
__string( comm, task->comm )
120
122
),
121
123
···
123
125
__entry->dst_root = dst_cgrp->root->hierarchy_id;
124
126
__entry->dst_id = dst_cgrp->id;
125
127
__entry->dst_level = dst_cgrp->level;
126
-
cgroup_path(dst_cgrp, __get_dynamic_array(dst_path),
127
-
__get_dynamic_array_len(dst_path));
128
+
__assign_str(dst_path, path);
128
129
__entry->pid = task->pid;
129
130
__assign_str(comm, task->comm);
130
131
),
···
135
138
136
139
DEFINE_EVENT(cgroup_migrate, cgroup_attach_task,
137
140
138
-
TP_PROTO(struct cgroup *dst_cgrp, struct task_struct *task, bool threadgroup),
141
+
TP_PROTO(struct cgroup *dst_cgrp, const char *path,
142
+
struct task_struct *task, bool threadgroup),
139
143
140
-
TP_ARGS(dst_cgrp, task, threadgroup)
144
+
TP_ARGS(dst_cgrp, path, task, threadgroup)
141
145
);
142
146
143
147
DEFINE_EVENT(cgroup_migrate, cgroup_transfer_tasks,
144
148
145
-
TP_PROTO(struct cgroup *dst_cgrp, struct task_struct *task, bool threadgroup),
149
+
TP_PROTO(struct cgroup *dst_cgrp, const char *path,
150
+
struct task_struct *task, bool threadgroup),
146
151
147
-
TP_ARGS(dst_cgrp, task, threadgroup)
152
+
TP_ARGS(dst_cgrp, path, task, threadgroup)
148
153
);
149
154
150
155
#endif /* _TRACE_CGROUP_H */
+26
kernel/cgroup/cgroup-internal.h
+26
kernel/cgroup/cgroup-internal.h
···
8
8
#include <linux/list.h>
9
9
#include <linux/refcount.h>
10
10
11
+
#define TRACE_CGROUP_PATH_LEN 1024
12
+
extern spinlock_t trace_cgroup_path_lock;
13
+
extern char trace_cgroup_path[TRACE_CGROUP_PATH_LEN];
14
+
15
+
/*
16
+
* cgroup_path() takes a spin lock. It is good practice not to take
17
+
* spin locks within trace point handlers, as they are mostly hidden
18
+
* from normal view. As cgroup_path() can take the kernfs_rename_lock
19
+
* spin lock, it is best to not call that function from the trace event
20
+
* handler.
21
+
*
22
+
* Note: trace_cgroup_##type##_enabled() is a static branch that will only
23
+
* be set when the trace event is enabled.
24
+
*/
25
+
#define TRACE_CGROUP_PATH(type, cgrp, ...) \
26
+
do { \
27
+
if (trace_cgroup_##type##_enabled()) { \
28
+
spin_lock(&trace_cgroup_path_lock); \
29
+
cgroup_path(cgrp, trace_cgroup_path, \
30
+
TRACE_CGROUP_PATH_LEN); \
31
+
trace_cgroup_##type(cgrp, trace_cgroup_path, \
32
+
##__VA_ARGS__); \
33
+
spin_unlock(&trace_cgroup_path_lock); \
34
+
} \
35
+
} while (0)
36
+
11
37
/*
12
38
* A cgroup can be associated with multiple css_sets as different tasks may
13
39
* belong to different cgroups on different hierarchies. In the other
+2
-2
kernel/cgroup/cgroup-v1.c
+2
-2
kernel/cgroup/cgroup-v1.c
···
135
135
if (task) {
136
136
ret = cgroup_migrate(task, false, &mgctx);
137
137
if (!ret)
138
-
trace_cgroup_transfer_tasks(to, task, false);
138
+
TRACE_CGROUP_PATH(transfer_tasks, to, task, false);
139
139
put_task_struct(task);
140
140
}
141
141
} while (task && !ret);
···
865
865
866
866
ret = kernfs_rename(kn, new_parent, new_name_str);
867
867
if (!ret)
868
-
trace_cgroup_rename(cgrp);
868
+
TRACE_CGROUP_PATH(rename, cgrp);
869
869
870
870
mutex_unlock(&cgroup_mutex);
871
871
+7
-5
kernel/cgroup/cgroup.c
+7
-5
kernel/cgroup/cgroup.c
···
83
83
EXPORT_SYMBOL_GPL(css_set_lock);
84
84
#endif
85
85
86
+
DEFINE_SPINLOCK(trace_cgroup_path_lock);
87
+
char trace_cgroup_path[TRACE_CGROUP_PATH_LEN];
88
+
86
89
/*
87
90
* Protects cgroup_idr and css_idr so that IDs can be released without
88
91
* grabbing cgroup_mutex.
···
2641
2638
cgroup_migrate_finish(&mgctx);
2642
2639
2643
2640
if (!ret)
2644
-
trace_cgroup_attach_task(dst_cgrp, leader, threadgroup);
2641
+
TRACE_CGROUP_PATH(attach_task, dst_cgrp, leader, threadgroup);
2645
2642
2646
2643
return ret;
2647
2644
}
···
4639
4636
struct cgroup *tcgrp;
4640
4637
4641
4638
/* cgroup release path */
4642
-
trace_cgroup_release(cgrp);
4639
+
TRACE_CGROUP_PATH(release, cgrp);
4643
4640
4644
4641
if (cgroup_on_dfl(cgrp))
4645
4642
cgroup_rstat_flush(cgrp);
···
4982
4979
if (ret)
4983
4980
goto out_destroy;
4984
4981
4985
-
trace_cgroup_mkdir(cgrp);
4982
+
TRACE_CGROUP_PATH(mkdir, cgrp);
4986
4983
4987
4984
/* let's create and online css's */
4988
4985
kernfs_activate(kn);
···
5170
5167
return 0;
5171
5168
5172
5169
ret = cgroup_destroy_locked(cgrp);
5173
-
5174
5170
if (!ret)
5175
-
trace_cgroup_rmdir(cgrp);
5171
+
TRACE_CGROUP_PATH(rmdir, cgrp);
5176
5172
5177
5173
cgroup_kn_unlock(kn);
5178
5174
return ret;