Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 59676610 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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
parents 9022ada8 e4f8d81c

include/trace/events/cgroup.h

+23 −24
Original line number Diff line number Diff line
@@ -53,24 +53,22 @@ DEFINE_EVENT(cgroup_root, cgroup_remount, 


DECLARE_EVENT_CLASS(cgroup,



	TP_PROTO(struct cgroup *cgrp),

	TP_PROTO(struct cgroup *cgrp, const char *path),



	TP_ARGS(cgrp),

	TP_ARGS(cgrp, path),



	TP_STRUCT__entry(

		__field(	int,		root			)

		__field(	int,		id			)

		__field(	int,		level			)

		__dynamic_array(char,		path,

				cgroup_path(cgrp, NULL, 0) + 1)

		__string(	path,		path			)

	),



	TP_fast_assign(

		__entry->root = cgrp->root->hierarchy_id;

		__entry->id = cgrp->id;

		__entry->level = cgrp->level;

		cgroup_path(cgrp, __get_dynamic_array(path),

				  __get_dynamic_array_len(path));

		__assign_str(path, path);

	),



	TP_printk("root=%d id=%d level=%d path=%s",
@@ -79,45 +77,45 @@ DECLARE_EVENT_CLASS(cgroup, 


DEFINE_EVENT(cgroup, cgroup_mkdir,



	TP_PROTO(struct cgroup *cgroup),

	TP_PROTO(struct cgroup *cgrp, const char *path),



	TP_ARGS(cgroup)

	TP_ARGS(cgrp, path)

);



DEFINE_EVENT(cgroup, cgroup_rmdir,



	TP_PROTO(struct cgroup *cgroup),

	TP_PROTO(struct cgroup *cgrp, const char *path),



	TP_ARGS(cgroup)

	TP_ARGS(cgrp, path)

);



DEFINE_EVENT(cgroup, cgroup_release,



	TP_PROTO(struct cgroup *cgroup),

	TP_PROTO(struct cgroup *cgrp, const char *path),



	TP_ARGS(cgroup)

	TP_ARGS(cgrp, path)

);



DEFINE_EVENT(cgroup, cgroup_rename,



	TP_PROTO(struct cgroup *cgroup),

	TP_PROTO(struct cgroup *cgrp, const char *path),



	TP_ARGS(cgroup)

	TP_ARGS(cgrp, path)

);



DECLARE_EVENT_CLASS(cgroup_migrate,



	TP_PROTO(struct cgroup *dst_cgrp, struct task_struct *task, bool threadgroup),

	TP_PROTO(struct cgroup *dst_cgrp, const char *path,

		 struct task_struct *task, bool threadgroup),



	TP_ARGS(dst_cgrp, task, threadgroup),

	TP_ARGS(dst_cgrp, path, task, threadgroup),



	TP_STRUCT__entry(

		__field(	int,		dst_root		)

		__field(	int,		dst_id			)

		__field(	int,		dst_level		)

		__dynamic_array(char,		dst_path,

				cgroup_path(dst_cgrp, NULL, 0) + 1)

		__field(	int,		pid			)

		__string(	dst_path,	path			)

		__string(	comm,		task->comm		)

	),
@@ -125,8 +123,7 @@ DECLARE_EVENT_CLASS(cgroup_migrate, 
		__entry->dst_root = dst_cgrp->root->hierarchy_id;

		__entry->dst_id = dst_cgrp->id;

		__entry->dst_level = dst_cgrp->level;

		cgroup_path(dst_cgrp, __get_dynamic_array(dst_path),

				      __get_dynamic_array_len(dst_path));

		__assign_str(dst_path, path);

		__entry->pid = task->pid;

		__assign_str(comm, task->comm);

	),
@@ -138,16 +135,18 @@ DECLARE_EVENT_CLASS(cgroup_migrate, 


DEFINE_EVENT(cgroup_migrate, cgroup_attach_task,



	TP_PROTO(struct cgroup *dst_cgrp, struct task_struct *task, bool threadgroup),

	TP_PROTO(struct cgroup *dst_cgrp, const char *path,

		 struct task_struct *task, bool threadgroup),



	TP_ARGS(dst_cgrp, task, threadgroup)

	TP_ARGS(dst_cgrp, path, task, threadgroup)

);



DEFINE_EVENT(cgroup_migrate, cgroup_transfer_tasks,



	TP_PROTO(struct cgroup *dst_cgrp, struct task_struct *task, bool threadgroup),

	TP_PROTO(struct cgroup *dst_cgrp, const char *path,

		 struct task_struct *task, bool threadgroup),



	TP_ARGS(dst_cgrp, task, threadgroup)

	TP_ARGS(dst_cgrp, path, task, threadgroup)

);



#endif /* _TRACE_CGROUP_H */

kernel/cgroup/cgroup-internal.h

+26 −0
Original line number Diff line number Diff line
@@ -8,6 +8,32 @@ 
#include <linux/list.h>

#include <linux/refcount.h>



#define TRACE_CGROUP_PATH_LEN 1024

extern spinlock_t trace_cgroup_path_lock;

extern char trace_cgroup_path[TRACE_CGROUP_PATH_LEN];



/*

 * cgroup_path() takes a spin lock. It is good practice not to take

 * spin locks within trace point handlers, as they are mostly hidden

 * from normal view. As cgroup_path() can take the kernfs_rename_lock

 * spin lock, it is best to not call that function from the trace event

 * handler.

 *

 * Note: trace_cgroup_##type##_enabled() is a static branch that will only

 *       be set when the trace event is enabled.

 */

#define TRACE_CGROUP_PATH(type, cgrp, ...)				\

	do {								\

		if (trace_cgroup_##type##_enabled()) {			\

			spin_lock(&trace_cgroup_path_lock);		\

			cgroup_path(cgrp, trace_cgroup_path,		\

				    TRACE_CGROUP_PATH_LEN);		\

			trace_cgroup_##type(cgrp, trace_cgroup_path,	\

					    ##__VA_ARGS__);		\

			spin_unlock(&trace_cgroup_path_lock);		\

		}							\

	} while (0)



/*

 * A cgroup can be associated with multiple css_sets as different tasks may

 * belong to different cgroups on different hierarchies.  In the other

kernel/cgroup/cgroup-v1.c

+2 −2
Original line number Diff line number Diff line
@@ -135,7 +135,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from) 
		if (task) {

			ret = cgroup_migrate(task, false, &mgctx);

			if (!ret)

				trace_cgroup_transfer_tasks(to, task, false);

				TRACE_CGROUP_PATH(transfer_tasks, to, task, false);

			put_task_struct(task);

		}

	} while (task && !ret);
@@ -865,7 +865,7 @@ static int cgroup1_rename(struct kernfs_node *kn, struct kernfs_node *new_parent 


	ret = kernfs_rename(kn, new_parent, new_name_str);

	if (!ret)

		trace_cgroup_rename(cgrp);

		TRACE_CGROUP_PATH(rename, cgrp);



	mutex_unlock(&cgroup_mutex);

kernel/cgroup/cgroup.c

+7 −5
Original line number Diff line number Diff line
@@ -83,6 +83,9 @@ EXPORT_SYMBOL_GPL(cgroup_mutex); 
EXPORT_SYMBOL_GPL(css_set_lock);

#endif



DEFINE_SPINLOCK(trace_cgroup_path_lock);

char trace_cgroup_path[TRACE_CGROUP_PATH_LEN];



/*

 * Protects cgroup_idr and css_idr so that IDs can be released without

 * grabbing cgroup_mutex.
@@ -2638,7 +2641,7 @@ int cgroup_attach_task(struct cgroup *dst_cgrp, struct task_struct *leader, 
	cgroup_migrate_finish(&mgctx);



	if (!ret)

		trace_cgroup_attach_task(dst_cgrp, leader, threadgroup);

		TRACE_CGROUP_PATH(attach_task, dst_cgrp, leader, threadgroup);



	return ret;

}
@@ -4636,7 +4639,7 @@ static void css_release_work_fn(struct work_struct *work) 
		struct cgroup *tcgrp;



		/* cgroup release path */

		trace_cgroup_release(cgrp);

		TRACE_CGROUP_PATH(release, cgrp);



		if (cgroup_on_dfl(cgrp))

			cgroup_rstat_flush(cgrp);
@@ -4979,7 +4982,7 @@ int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, umode_t mode) 
	if (ret)

		goto out_destroy;



	trace_cgroup_mkdir(cgrp);

	TRACE_CGROUP_PATH(mkdir, cgrp);



	/* let's create and online css's */

	kernfs_activate(kn);
@@ -5167,9 +5170,8 @@ int cgroup_rmdir(struct kernfs_node *kn) 
		return 0;



	ret = cgroup_destroy_locked(cgrp);



	if (!ret)

		trace_cgroup_rmdir(cgrp);

		TRACE_CGROUP_PATH(rmdir, cgrp);



	cgroup_kn_unlock(kn);

	return ret;