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authorTejun Heo <tj@kernel.org>2013-01-23 09:32:30 -0800
committerTejun Heo <tj@kernel.org>2013-01-23 09:32:30 -0800
commit9fdb04cdc5566d6ba68283a0bebe49667ca0b0e8 (patch)
tree998ae384cdfa764686f85e0b0dc57fc40b407d21 /kernel/async.c
parent52722794d6a48162fd8906d54618ae60a4abdb21 (diff)
downloadvexpress-lsk-9fdb04cdc5566d6ba68283a0bebe49667ca0b0e8.tar.gz
async: replace list of active domains with global list of pending items
Global synchronization - async_synchronize_full() - is currently implemented by keeping a list of all active registered domains and syncing them one by one until no domain is active. While this isn't necessarily a complex scheme, it can easily be simplified by keeping global list of the pending items of all registered active domains instead of list of domains and simply using the globl pending list the same way as domain syncing. This patch replaces async_domains with async_global_pending and update lowest_in_progress() to use the global pending list if @domain is %NULL. async_synchronize_full_domain(NULL) is now allowed and equivalent to async_synchronize_full(). As no one is calling with NULL domain, this doesn't affect any existing users. async_register_mutex is no longer necessary and dropped. Signed-off-by: Tejun 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>
Diffstat (limited to 'kernel/async.c')
-rw-r--r--kernel/async.c63
1 files changed, 29 insertions, 34 deletions
diff --git a/kernel/async.c b/kernel/async.c
index 7c9f50f436d..6958000eeb4 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -64,13 +64,13 @@ static async_cookie_t next_cookie = 1;
#define MAX_WORK 32768
#define ASYNC_COOKIE_MAX ULLONG_MAX /* infinity cookie */
+static LIST_HEAD(async_global_pending); /* pending from all registered doms */
static ASYNC_DOMAIN(async_dfl_domain);
-static LIST_HEAD(async_domains);
static DEFINE_SPINLOCK(async_lock);
-static DEFINE_MUTEX(async_register_mutex);
struct async_entry {
- struct list_head list;
+ struct list_head domain_list;
+ struct list_head global_list;
struct work_struct work;
async_cookie_t cookie;
async_func_ptr *func;
@@ -84,15 +84,25 @@ static atomic_t entry_count;
static async_cookie_t lowest_in_progress(struct async_domain *domain)
{
+ struct async_entry *first = NULL;
async_cookie_t ret = ASYNC_COOKIE_MAX;
unsigned long flags;
spin_lock_irqsave(&async_lock, flags);
- if (!list_empty(&domain->pending)) {
- struct async_entry *first = list_first_entry(&domain->pending,
- struct async_entry, list);
- ret = first->cookie;
+
+ if (domain) {
+ if (!list_empty(&domain->pending))
+ first = list_first_entry(&domain->pending,
+ struct async_entry, domain_list);
+ } else {
+ if (!list_empty(&async_global_pending))
+ first = list_first_entry(&async_global_pending,
+ struct async_entry, global_list);
}
+
+ if (first)
+ ret = first->cookie;
+
spin_unlock_irqrestore(&async_lock, flags);
return ret;
}
@@ -106,7 +116,6 @@ static void async_run_entry_fn(struct work_struct *work)
container_of(work, struct async_entry, work);
unsigned long flags;
ktime_t uninitialized_var(calltime), delta, rettime;
- struct async_domain *domain = entry->domain;
/* 1) run (and print duration) */
if (initcall_debug && system_state == SYSTEM_BOOTING) {
@@ -127,9 +136,8 @@ static void async_run_entry_fn(struct work_struct *work)
/* 2) remove self from the pending queues */
spin_lock_irqsave(&async_lock, flags);
- list_del(&entry->list);
- if (domain->registered && list_empty(&domain->pending))
- list_del_init(&domain->node);
+ list_del_init(&entry->domain_list);
+ list_del_init(&entry->global_list);
/* 3) free the entry */
kfree(entry);
@@ -170,10 +178,14 @@ static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct a
entry->domain = domain;
spin_lock_irqsave(&async_lock, flags);
+
+ /* allocate cookie and queue */
newcookie = entry->cookie = next_cookie++;
- if (domain->registered && list_empty(&domain->pending))
- list_add_tail(&domain->node, &async_domains);
- list_add_tail(&entry->list, &domain->pending);
+
+ list_add_tail(&entry->domain_list, &domain->pending);
+ if (domain->registered)
+ list_add_tail(&entry->global_list, &async_global_pending);
+
atomic_inc(&entry_count);
spin_unlock_irqrestore(&async_lock, flags);
@@ -226,18 +238,7 @@ EXPORT_SYMBOL_GPL(async_schedule_domain);
*/
void async_synchronize_full(void)
{
- mutex_lock(&async_register_mutex);
- do {
- struct async_domain *domain = NULL;
-
- spin_lock_irq(&async_lock);
- if (!list_empty(&async_domains))
- domain = list_first_entry(&async_domains, typeof(*domain), node);
- spin_unlock_irq(&async_lock);
-
- async_synchronize_cookie_domain(ASYNC_COOKIE_MAX, domain);
- } while (!list_empty(&async_domains));
- mutex_unlock(&async_register_mutex);
+ async_synchronize_full_domain(NULL);
}
EXPORT_SYMBOL_GPL(async_synchronize_full);
@@ -252,13 +253,10 @@ EXPORT_SYMBOL_GPL(async_synchronize_full);
*/
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->pending));
+ WARN_ON(!domain->registered || !list_empty(&domain->pending));
domain->registered = 0;
spin_unlock_irq(&async_lock);
- mutex_unlock(&async_register_mutex);
}
EXPORT_SYMBOL_GPL(async_unregister_domain);
@@ -278,7 +276,7 @@ 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
- * @domain: the domain to synchronize
+ * @domain: the domain to synchronize (%NULL for all registered domains)
*
* This function waits until all asynchronous function calls for the
* synchronization domain specified by @domain submitted prior to @cookie
@@ -288,9 +286,6 @@ void async_synchronize_cookie_domain(async_cookie_t cookie, struct async_domain
{
ktime_t uninitialized_var(starttime), delta, endtime;
- if (!domain)
- return;
-
if (initcall_debug && system_state == SYSTEM_BOOTING) {
printk(KERN_DEBUG "async_waiting @ %i\n", task_pid_nr(current));
starttime = ktime_get();