#include <linux/module.h>
#include <linux/wait.h>
#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/kthread.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
#include <asm/atomic.h>
static async_cookie_t next_cookie = 1;
-#define MAX_THREADS 256
#define MAX_WORK 32768
static LIST_HEAD(async_pending);
static LIST_HEAD(async_running);
static DEFINE_SPINLOCK(async_lock);
-static int async_enabled = 0;
-
struct async_entry {
- struct list_head list;
- async_cookie_t cookie;
- async_func_ptr *func;
- void *data;
- struct list_head *running;
+ struct list_head list;
+ struct work_struct work;
+ async_cookie_t cookie;
+ async_func_ptr *func;
+ void *data;
+ struct list_head *running;
};
static DECLARE_WAIT_QUEUE_HEAD(async_done);
-static DECLARE_WAIT_QUEUE_HEAD(async_new);
static atomic_t entry_count;
-static atomic_t thread_count;
extern int initcall_debug;
static async_cookie_t __lowest_in_progress(struct list_head *running)
{
struct async_entry *entry;
+
if (!list_empty(running)) {
entry = list_first_entry(running,
struct async_entry, list);
return entry->cookie;
- } else if (!list_empty(&async_pending)) {
- entry = list_first_entry(&async_pending,
- struct async_entry, list);
- return entry->cookie;
- } else {
- /* nothing in progress... next_cookie is "infinity" */
- return next_cookie;
}
+ list_for_each_entry(entry, &async_pending, list)
+ if (entry->running == running)
+ return entry->cookie;
+
+ return next_cookie; /* "infinity" value */
}
static async_cookie_t lowest_in_progress(struct list_head *running)
spin_unlock_irqrestore(&async_lock, flags);
return ret;
}
+
/*
* pick the first pending entry and run it
*/
-static void run_one_entry(void)
+static void async_run_entry_fn(struct work_struct *work)
{
+ struct async_entry *entry =
+ container_of(work, struct async_entry, work);
unsigned long flags;
- struct async_entry *entry;
ktime_t calltime, delta, rettime;
- /* 1) pick one task from the pending queue */
-
+ /* 1) move self to the running queue */
spin_lock_irqsave(&async_lock, flags);
- if (list_empty(&async_pending))
- goto out;
- entry = list_first_entry(&async_pending, struct async_entry, list);
-
- /* 2) move it to the running queue */
- list_del(&entry->list);
- list_add_tail(&entry->list, &async_running);
+ list_move_tail(&entry->list, entry->running);
spin_unlock_irqrestore(&async_lock, flags);
- /* 3) run it (and print duration)*/
+ /* 2) run (and print duration) */
if (initcall_debug && system_state == SYSTEM_BOOTING) {
- printk("calling %lli_%pF @ %i\n", entry->cookie, entry->func, task_pid_nr(current));
+ printk("calling %lli_%pF @ %i\n", (long long)entry->cookie,
+ entry->func, task_pid_nr(current));
calltime = ktime_get();
}
entry->func(entry->data, entry->cookie);
if (initcall_debug && system_state == SYSTEM_BOOTING) {
rettime = ktime_get();
delta = ktime_sub(rettime, calltime);
- printk("initcall %lli_%pF returned 0 after %lld usecs\n", entry->cookie,
- entry->func, ktime_to_ns(delta) >> 10);
+ printk("initcall %lli_%pF returned 0 after %lld usecs\n",
+ (long long)entry->cookie,
+ entry->func,
+ (long long)ktime_to_ns(delta) >> 10);
}
- /* 4) remove it from the running queue */
+ /* 3) remove self from the running queue */
spin_lock_irqsave(&async_lock, flags);
list_del(&entry->list);
- /* 5) free the entry */
+ /* 4) free the entry */
kfree(entry);
atomic_dec(&entry_count);
spin_unlock_irqrestore(&async_lock, flags);
- /* 6) wake up any waiters. */
+ /* 5) wake up any waiters */
wake_up(&async_done);
- return;
-
-out:
- spin_unlock_irqrestore(&async_lock, flags);
}
-
static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct list_head *running)
{
struct async_entry *entry;
unsigned long flags;
async_cookie_t newcookie;
-
/* allow irq-off callers */
entry = kzalloc(sizeof(struct async_entry), GFP_ATOMIC);
* If we're out of memory or if there's too much work
* pending already, we execute synchronously.
*/
- if (!async_enabled || !entry || atomic_read(&entry_count) > MAX_WORK) {
+ if (!entry || atomic_read(&entry_count) > MAX_WORK) {
kfree(entry);
spin_lock_irqsave(&async_lock, flags);
newcookie = next_cookie++;
ptr(data, newcookie);
return newcookie;
}
+ INIT_WORK(&entry->work, async_run_entry_fn);
entry->func = ptr;
entry->data = data;
entry->running = running;
list_add_tail(&entry->list, &async_pending);
atomic_inc(&entry_count);
spin_unlock_irqrestore(&async_lock, flags);
- wake_up(&async_new);
+
+ /* schedule for execution */
+ queue_work(system_unbound_wq, &entry->work);
+
return newcookie;
}
+/**
+ * async_schedule - schedule a function for asynchronous execution
+ * @ptr: function to execute asynchronously
+ * @data: data pointer to pass to the function
+ *
+ * Returns an async_cookie_t that may be used for checkpointing later.
+ * Note: This function may be called from atomic or non-atomic contexts.
+ */
async_cookie_t async_schedule(async_func_ptr *ptr, void *data)
{
- return __async_schedule(ptr, data, &async_pending);
+ return __async_schedule(ptr, data, &async_running);
}
EXPORT_SYMBOL_GPL(async_schedule);
-async_cookie_t async_schedule_special(async_func_ptr *ptr, void *data, struct list_head *running)
+/**
+ * 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
+ *
+ * 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.
+ */
+async_cookie_t async_schedule_domain(async_func_ptr *ptr, void *data,
+ struct list_head *running)
{
return __async_schedule(ptr, data, running);
}
-EXPORT_SYMBOL_GPL(async_schedule_special);
+EXPORT_SYMBOL_GPL(async_schedule_domain);
+/**
+ * async_synchronize_full - synchronize all asynchronous function calls
+ *
+ * This function waits until all asynchronous function calls have been done.
+ */
void async_synchronize_full(void)
{
do {
}
EXPORT_SYMBOL_GPL(async_synchronize_full);
-void async_synchronize_full_special(struct list_head *list)
+/**
+ * async_synchronize_full_domain - synchronize all asynchronous function within a certain domain
+ * @list: running list to synchronize on
+ *
+ * This function waits until all asynchronous function calls for the
+ * synchronization domain specified by the running list @list have been done.
+ */
+void async_synchronize_full_domain(struct list_head *list)
{
- async_synchronize_cookie_special(next_cookie, list);
+ async_synchronize_cookie_domain(next_cookie, list);
}
-EXPORT_SYMBOL_GPL(async_synchronize_full_special);
+EXPORT_SYMBOL_GPL(async_synchronize_full_domain);
-void async_synchronize_cookie_special(async_cookie_t cookie, struct list_head *running)
+/**
+ * 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
+ *
+ * This function waits until all asynchronous function calls for the
+ * synchronization domain specified by the running list @list submitted
+ * prior to @cookie have been done.
+ */
+void async_synchronize_cookie_domain(async_cookie_t cookie,
+ struct list_head *running)
{
ktime_t starttime, delta, endtime;
delta = ktime_sub(endtime, starttime);
printk("async_continuing @ %i after %lli usec\n",
- task_pid_nr(current), ktime_to_ns(delta) >> 10);
+ task_pid_nr(current),
+ (long long)ktime_to_ns(delta) >> 10);
}
}
-EXPORT_SYMBOL_GPL(async_synchronize_cookie_special);
+EXPORT_SYMBOL_GPL(async_synchronize_cookie_domain);
+/**
+ * async_synchronize_cookie - synchronize asynchronous function calls with cookie checkpointing
+ * @cookie: async_cookie_t to use as checkpoint
+ *
+ * This function waits until all asynchronous function calls prior to @cookie
+ * have been done.
+ */
void async_synchronize_cookie(async_cookie_t cookie)
{
- async_synchronize_cookie_special(cookie, &async_running);
+ async_synchronize_cookie_domain(cookie, &async_running);
}
EXPORT_SYMBOL_GPL(async_synchronize_cookie);
-
-
-static int async_thread(void *unused)
-{
- DECLARE_WAITQUEUE(wq, current);
- add_wait_queue(&async_new, &wq);
-
- while (!kthread_should_stop()) {
- int ret = HZ;
- set_current_state(TASK_INTERRUPTIBLE);
- /*
- * check the list head without lock.. false positives
- * are dealt with inside run_one_entry() while holding
- * the lock.
- */
- rmb();
- if (!list_empty(&async_pending))
- run_one_entry();
- else
- ret = schedule_timeout(HZ);
-
- if (ret == 0) {
- /*
- * we timed out, this means we as thread are redundant.
- * we sign off and die, but we to avoid any races there
- * is a last-straw check to see if work snuck in.
- */
- atomic_dec(&thread_count);
- wmb(); /* manager must see our departure first */
- if (list_empty(&async_pending))
- break;
- /*
- * woops work came in between us timing out and us
- * signing off; we need to stay alive and keep working.
- */
- atomic_inc(&thread_count);
- }
- }
- remove_wait_queue(&async_new, &wq);
-
- return 0;
-}
-
-static int async_manager_thread(void *unused)
-{
- DECLARE_WAITQUEUE(wq, current);
- add_wait_queue(&async_new, &wq);
-
- while (!kthread_should_stop()) {
- int tc, ec;
-
- set_current_state(TASK_INTERRUPTIBLE);
-
- tc = atomic_read(&thread_count);
- rmb();
- ec = atomic_read(&entry_count);
-
- while (tc < ec && tc < MAX_THREADS) {
- kthread_run(async_thread, NULL, "async/%i", tc);
- atomic_inc(&thread_count);
- tc++;
- }
-
- schedule();
- }
- remove_wait_queue(&async_new, &wq);
-
- return 0;
-}
-
-static int __init async_init(void)
-{
- if (async_enabled)
- kthread_run(async_manager_thread, NULL, "async/mgr");
- return 0;
-}
-
-static int __init setup_async(char *str)
-{
- async_enabled = 1;
- return 1;
-}
-
-__setup("fastboot", setup_async);
-
-
-core_initcall(async_init);
projects / linux-flexiantxendom0-natty.git / blobdiff