Commit 8723d503 authored by Tejun Heo's avatar Tejun Heo
Browse files

async: bring sanity to the use of words domain and running 



In the beginning, running lists were literal struct list_heads.  Later
on, struct async_domain was added.  For some reason, while the
conversion substituted list_heads with async_domains, the variable
names weren't fully converted.  In more places, "running" was used for
struct async_domain while other places adopted new "domain" name.

The situation is made much worse by having async_domain's running list
named "domain" and async_entry's field pointing to async_domain named
"running".

So, we end up with mix of "running" and "domain" for variable names
for async_domain, with the field names of async_domain and async_entry
swapped between "running" and "domain".

It feels almost intentionally made to be as confusing as possible.
Bring some sanity by

* Renaming all async_domain variables "domain".

* s/async_running/async_dfl_domain/

* s/async_domain->domain/async_domain->running/

* s/async_entry->running/async_entry->domain/

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <djbw@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
parent c14afb82

include/linux/async.h

+3 −3
Original line number Diff line number Diff line
@@ -19,7 +19,7 @@ typedef u64 async_cookie_t; 
typedef void (async_func_ptr) (void *data, async_cookie_t cookie);

struct async_domain {

	struct list_head node;

	struct list_head domain;

	struct list_head running;

	int count;

	unsigned registered:1;

};
@@ -29,7 +29,7 @@ struct async_domain { 
 */

#define ASYNC_DOMAIN(_name) \

	struct async_domain _name = { .node = LIST_HEAD_INIT(_name.node), \

				      .domain = LIST_HEAD_INIT(_name.domain), \

				      .running = LIST_HEAD_INIT(_name.running), \

				      .count = 0, \

				      .registered = 1 }
@@ -39,7 +39,7 @@ struct async_domain { 
 */

#define ASYNC_DOMAIN_EXCLUSIVE(_name) \

	struct async_domain _name = { .node = LIST_HEAD_INIT(_name.node), \

				      .domain = LIST_HEAD_INIT(_name.domain), \

				      .running = LIST_HEAD_INIT(_name.running), \

				      .count = 0, \

				      .registered = 0 }

kernel/async.c

+34 −34
Original line number Diff line number Diff line
@@ -64,7 +64,7 @@ static async_cookie_t next_cookie = 1; 
#define MAX_WORK	32768



static LIST_HEAD(async_pending);

static ASYNC_DOMAIN(async_running);

static ASYNC_DOMAIN(async_dfl_domain);

static LIST_HEAD(async_domains);

static DEFINE_SPINLOCK(async_lock);

static DEFINE_MUTEX(async_register_mutex);
@@ -75,7 +75,7 @@ struct async_entry { 
	async_cookie_t		cookie;

	async_func_ptr		*func;

	void			*data;

	struct async_domain	*running;

	struct async_domain	*domain;

};



static DECLARE_WAIT_QUEUE_HEAD(async_done);
@@ -86,7 +86,7 @@ static atomic_t entry_count; 
/*

 * MUST be called with the lock held!

 */

static async_cookie_t  __lowest_in_progress(struct async_domain *running)

static async_cookie_t __lowest_in_progress(struct async_domain *domain)

{

	async_cookie_t first_running = next_cookie;	/* infinity value */

	async_cookie_t first_pending = next_cookie;	/* ditto */
@@ -96,13 +96,13 @@ static async_cookie_t __lowest_in_progress(struct async_domain *running) 
	 * Both running and pending lists are sorted but not disjoint.

	 * Take the first cookies from both and return the min.

	 */

	if (!list_empty(&running->domain)) {

		entry = list_first_entry(&running->domain, typeof(*entry), list);

	if (!list_empty(&domain->running)) {

		entry = list_first_entry(&domain->running, typeof(*entry), list);

		first_running = entry->cookie;

	}



	list_for_each_entry(entry, &async_pending, list) {

		if (entry->running == running) {

		if (entry->domain == domain) {

			first_pending = entry->cookie;

			break;

		}
@@ -111,13 +111,13 @@ static async_cookie_t __lowest_in_progress(struct async_domain *running) 
	return min(first_running, first_pending);

}



static async_cookie_t  lowest_in_progress(struct async_domain *running)

static async_cookie_t lowest_in_progress(struct async_domain *domain)

{

	unsigned long flags;

	async_cookie_t ret;



	spin_lock_irqsave(&async_lock, flags);

	ret = __lowest_in_progress(running);

	ret = __lowest_in_progress(domain);

	spin_unlock_irqrestore(&async_lock, flags);

	return ret;

}
@@ -132,11 +132,11 @@ static void async_run_entry_fn(struct work_struct *work) 
	struct async_entry *pos;

	unsigned long flags;

	ktime_t uninitialized_var(calltime), delta, rettime;

	struct async_domain *running = entry->running;

	struct async_domain *domain = entry->domain;



	/* 1) move self to the running queue, make sure it stays sorted */

	spin_lock_irqsave(&async_lock, flags);

	list_for_each_entry_reverse(pos, &running->domain, list)

	list_for_each_entry_reverse(pos, &domain->running, list)

		if (entry->cookie < pos->cookie)

			break;

	list_move_tail(&entry->list, &pos->list);
@@ -162,8 +162,8 @@ static void async_run_entry_fn(struct work_struct *work) 
	/* 3) remove self from the running queue */

	spin_lock_irqsave(&async_lock, flags);

	list_del(&entry->list);

	if (running->registered && --running->count == 0)

		list_del_init(&running->node);

	if (domain->registered && --domain->count == 0)

		list_del_init(&domain->node);



	/* 4) free the entry */

	kfree(entry);
@@ -175,7 +175,7 @@ static void async_run_entry_fn(struct work_struct *work) 
	wake_up(&async_done);

}



static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct async_domain *running)

static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct async_domain *domain)

{

	struct async_entry *entry;

	unsigned long flags;
@@ -201,13 +201,13 @@ static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct a 
	INIT_WORK(&entry->work, async_run_entry_fn);

	entry->func = ptr;

	entry->data = data;

	entry->running = running;

	entry->domain = domain;



	spin_lock_irqsave(&async_lock, flags);

	newcookie = entry->cookie = next_cookie++;

	list_add_tail(&entry->list, &async_pending);

	if (running->registered && running->count++ == 0)

		list_add_tail(&running->node, &async_domains);

	if (domain->registered && domain->count++ == 0)

		list_add_tail(&domain->node, &async_domains);

	atomic_inc(&entry_count);

	spin_unlock_irqrestore(&async_lock, flags);
@@ -230,7 +230,7 @@ static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct a 
 */

async_cookie_t async_schedule(async_func_ptr *ptr, void *data)

{

	return __async_schedule(ptr, data, &async_running);

	return __async_schedule(ptr, data, &async_dfl_domain);

}

EXPORT_SYMBOL_GPL(async_schedule);
@@ -238,18 +238,18 @@ EXPORT_SYMBOL_GPL(async_schedule); 
 * async_schedule_domain - schedule a function for asynchronous execution within a certain domain

 * @ptr: function to execute asynchronously

 * @data: data pointer to pass to the function

 * @running: running list for the domain

 * @domain: the domain

 *

 * Returns an async_cookie_t that may be used for checkpointing later.

 * @running may be used in the async_synchronize_*_domain() functions

 * to wait within a certain synchronization domain rather than globally.

 * A synchronization domain is specified via the running queue @running to use.

 * Note: This function may be called from atomic or non-atomic contexts.

 * @domain may be used in the async_synchronize_*_domain() functions to

 * wait within a certain synchronization domain rather than globally.  A

 * synchronization domain is specified via @domain.  Note: This function

 * may be called from atomic or non-atomic contexts.

 */

async_cookie_t async_schedule_domain(async_func_ptr *ptr, void *data,

				     struct async_domain *running)

				     struct async_domain *domain)

{

	return __async_schedule(ptr, data, running);

	return __async_schedule(ptr, data, domain);

}

EXPORT_SYMBOL_GPL(async_schedule_domain);
@@ -289,7 +289,7 @@ void async_unregister_domain(struct async_domain *domain) 
	mutex_lock(&async_register_mutex);

	spin_lock_irq(&async_lock);

	WARN_ON(!domain->registered || !list_empty(&domain->node) ||

		!list_empty(&domain->domain));

		!list_empty(&domain->running));

	domain->registered = 0;

	spin_unlock_irq(&async_lock);

	mutex_unlock(&async_register_mutex);
@@ -298,10 +298,10 @@ EXPORT_SYMBOL_GPL(async_unregister_domain); 


/**

 * async_synchronize_full_domain - synchronize all asynchronous function within a certain domain

 * @domain: running list to synchronize on

 * @domain: the domain to synchronize

 *

 * This function waits until all asynchronous function calls for the

 * synchronization domain specified by the running list @domain have been done.

 * synchronization domain specified by @domain have been done.

 */

void async_synchronize_full_domain(struct async_domain *domain)

{
@@ -312,17 +312,17 @@ EXPORT_SYMBOL_GPL(async_synchronize_full_domain); 
/**

 * async_synchronize_cookie_domain - synchronize asynchronous function calls within a certain domain with cookie checkpointing

 * @cookie: async_cookie_t to use as checkpoint

 * @running: running list to synchronize on

 * @domain: the domain to synchronize

 *

 * This function waits until all asynchronous function calls for the

 * synchronization domain specified by running list @running submitted

 * prior to @cookie have been done.

 * synchronization domain specified by @domain submitted prior to @cookie

 * have been done.

 */

void async_synchronize_cookie_domain(async_cookie_t cookie, struct async_domain *running)

void async_synchronize_cookie_domain(async_cookie_t cookie, struct async_domain *domain)

{

	ktime_t uninitialized_var(starttime), delta, endtime;



	if (!running)

	if (!domain)

		return;



	if (initcall_debug && system_state == SYSTEM_BOOTING) {
@@ -330,7 +330,7 @@ void async_synchronize_cookie_domain(async_cookie_t cookie, struct async_domain 
		starttime = ktime_get();

	}



	wait_event(async_done, lowest_in_progress(running) >= cookie);

	wait_event(async_done, lowest_in_progress(domain) >= cookie);



	if (initcall_debug && system_state == SYSTEM_BOOTING) {

		endtime = ktime_get();
@@ -352,7 +352,7 @@ EXPORT_SYMBOL_GPL(async_synchronize_cookie_domain); 
 */

void async_synchronize_cookie(async_cookie_t cookie)

{

	async_synchronize_cookie_domain(cookie, &async_running);

	async_synchronize_cookie_domain(cookie, &async_dfl_domain);

}

EXPORT_SYMBOL_GPL(async_synchronize_cookie);

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