Place some LIKELY and UNLIKELY hints in kernel where I can definitively say anything about it and where it could make a small difference.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@19433 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Michael Sevakis 2008-12-14 07:09:26 +00:00
parent 5b2a600007
commit 0fab3e36f3
2 changed files with 28 additions and 28 deletions

View file

@ -391,7 +391,7 @@ static inline void queue_do_unblock_sender(struct queue_sender_list *send,
{ {
struct thread_entry **spp = &send->senders[i]; struct thread_entry **spp = &send->senders[i];
if(*spp) if(UNLIKELY(*spp))
{ {
queue_release_sender(spp, 0); queue_release_sender(spp, 0);
} }
@ -665,13 +665,13 @@ intptr_t queue_send(struct event_queue *q, long id, intptr_t data)
q->events[wr].id = id; q->events[wr].id = id;
q->events[wr].data = data; q->events[wr].data = data;
if(q->send) if(LIKELY(q->send))
{ {
struct queue_sender_list *send = q->send; struct queue_sender_list *send = q->send;
struct thread_entry **spp = &send->senders[wr]; struct thread_entry **spp = &send->senders[wr];
struct thread_entry *current = cores[CURRENT_CORE].running; struct thread_entry *current = cores[CURRENT_CORE].running;
if(*spp) if(UNLIKELY(*spp))
{ {
/* overflow protect - unblock any thread waiting at this index */ /* overflow protect - unblock any thread waiting at this index */
queue_release_sender(spp, 0); queue_release_sender(spp, 0);
@ -735,7 +735,7 @@ void queue_reply(struct event_queue *q, intptr_t retval)
int oldlevel = disable_irq_save(); int oldlevel = disable_irq_save();
corelock_lock(&q->cl); corelock_lock(&q->cl);
/* Double-check locking */ /* Double-check locking */
IF_COP( if(q->send && q->send->curr_sender) ) IF_COP( if(LIKELY(q->send && q->send->curr_sender)) )
{ {
queue_release_sender(&q->send->curr_sender, retval); queue_release_sender(&q->send->curr_sender, retval);
} }
@ -890,7 +890,7 @@ void mutex_lock(struct mutex *m)
/* lock out other cores */ /* lock out other cores */
corelock_lock(&m->cl); corelock_lock(&m->cl);
if(m->locked == 0) if(LIKELY(m->locked == 0))
{ {
/* lock is open */ /* lock is open */
MUTEX_SET_THREAD(m, current); MUTEX_SET_THREAD(m, current);
@ -933,7 +933,7 @@ void mutex_unlock(struct mutex *m)
corelock_lock(&m->cl); corelock_lock(&m->cl);
/* transfer to next queued thread if any */ /* transfer to next queued thread if any */
if(m->queue == NULL) if(LIKELY(m->queue == NULL))
{ {
/* no threads waiting - open the lock */ /* no threads waiting - open the lock */
MUTEX_SET_THREAD(m, NULL); MUTEX_SET_THREAD(m, NULL);
@ -1031,7 +1031,7 @@ void semaphore_wait(struct semaphore *s)
corelock_lock(&s->cl); corelock_lock(&s->cl);
if(--s->count >= 0) if(LIKELY(--s->count >= 0))
{ {
/* wait satisfied */ /* wait satisfied */
corelock_unlock(&s->cl); corelock_unlock(&s->cl);
@ -1099,7 +1099,7 @@ int wakeup_wait(struct wakeup *w, int timeout)
corelock_lock(&w->cl); corelock_lock(&w->cl);
if(w->signalled == 0 && timeout != TIMEOUT_NOBLOCK) if(LIKELY(w->signalled == 0 && timeout != TIMEOUT_NOBLOCK))
{ {
struct thread_entry * current = cores[CURRENT_CORE].running; struct thread_entry * current = cores[CURRENT_CORE].running;
@ -1118,7 +1118,7 @@ int wakeup_wait(struct wakeup *w, int timeout)
corelock_lock(&w->cl); corelock_lock(&w->cl);
} }
if(w->signalled == 0) if(UNLIKELY(w->signalled == 0))
{ {
/* Timed-out or failed */ /* Timed-out or failed */
ret = (timeout != TIMEOUT_BLOCK) ? ret = (timeout != TIMEOUT_BLOCK) ?

View file

@ -1454,7 +1454,7 @@ static inline void set_running_thread_priority(
static int find_highest_priority_in_list_l( static int find_highest_priority_in_list_l(
struct thread_entry * const thread) struct thread_entry * const thread)
{ {
if (thread != NULL) if (LIKELY(thread != NULL))
{ {
/* Go though list until the ending up at the initial thread */ /* Go though list until the ending up at the initial thread */
int highest_priority = thread->priority; int highest_priority = thread->priority;
@ -1538,7 +1538,7 @@ static struct thread_entry *
next = bl->thread; next = bl->thread;
if (next == tstart) if (UNLIKELY(next == tstart))
break; /* Full-circle - deadlock! */ break; /* Full-circle - deadlock! */
UNLOCK_THREAD(current); UNLOCK_THREAD(current);
@ -1549,7 +1549,7 @@ static struct thread_entry *
LOCK_THREAD(next); LOCK_THREAD(next);
/* Blocker could change - retest condition */ /* Blocker could change - retest condition */
if (bl->thread == next) if (LIKELY(bl->thread == next))
break; break;
UNLOCK_THREAD(next); UNLOCK_THREAD(next);
@ -1638,7 +1638,7 @@ struct thread_entry *
next = bl->thread; next = bl->thread;
if (next == tstart) if (UNLIKELY(next == tstart))
break; /* Full-circle - deadlock! */ break; /* Full-circle - deadlock! */
UNLOCK_THREAD(thread); UNLOCK_THREAD(thread);
@ -1649,7 +1649,7 @@ struct thread_entry *
LOCK_THREAD(next); LOCK_THREAD(next);
/* Blocker could change - retest condition */ /* Blocker could change - retest condition */
if (bl->thread == next) if (LIKELY(bl->thread == next))
break; break;
UNLOCK_THREAD(next); UNLOCK_THREAD(next);
@ -1663,7 +1663,7 @@ struct thread_entry *
UNLOCK_THREAD(bl_t); UNLOCK_THREAD(bl_t);
#if NUM_CORES > 1 #if NUM_CORES > 1
if (thread != tstart) if (UNLIKELY(thread != tstart))
{ {
/* Relock original if it changed */ /* Relock original if it changed */
LOCK_THREAD(tstart); LOCK_THREAD(tstart);
@ -1715,7 +1715,7 @@ struct thread_entry *
next = *thread->bqp; next = *thread->bqp;
if (next == NULL) if (LIKELY(next == NULL))
{ {
/* Expected shortcut - no more waiters */ /* Expected shortcut - no more waiters */
bl_pr = PRIORITY_IDLE; bl_pr = PRIORITY_IDLE;
@ -1830,7 +1830,7 @@ void check_tmo_threads(void)
* list. */ * list. */
remove_from_list_tmo(curr); remove_from_list_tmo(curr);
} }
else if (TIME_BEFORE(tick, curr->tmo_tick)) else if (LIKELY(TIME_BEFORE(tick, curr->tmo_tick)))
{ {
/* Timeout still pending - this will be the usual case */ /* Timeout still pending - this will be the usual case */
if (TIME_BEFORE(curr->tmo_tick, next_tmo_check)) if (TIME_BEFORE(curr->tmo_tick, next_tmo_check))
@ -1850,7 +1850,7 @@ void check_tmo_threads(void)
/* Lock the waiting thread's kernel object */ /* Lock the waiting thread's kernel object */
struct corelock *ocl = curr->obj_cl; struct corelock *ocl = curr->obj_cl;
if (corelock_try_lock(ocl) == 0) if (UNLIKELY(corelock_try_lock(ocl) == 0))
{ {
/* Need to retry in the correct order though the need is /* Need to retry in the correct order though the need is
* unlikely */ * unlikely */
@ -1858,7 +1858,7 @@ void check_tmo_threads(void)
corelock_lock(ocl); corelock_lock(ocl);
LOCK_THREAD(curr); LOCK_THREAD(curr);
if (curr->state != STATE_BLOCKED_W_TMO) if (UNLIKELY(curr->state != STATE_BLOCKED_W_TMO))
{ {
/* Thread was woken or removed explicitely while slot /* Thread was woken or removed explicitely while slot
* was unlocked */ * was unlocked */
@ -1915,7 +1915,7 @@ static inline void run_blocking_ops(
struct thread_blk_ops *ops = &cores[core].blk_ops; struct thread_blk_ops *ops = &cores[core].blk_ops;
const unsigned flags = ops->flags; const unsigned flags = ops->flags;
if (flags == TBOP_CLEAR) if (LIKELY(flags == TBOP_CLEAR))
return; return;
switch (flags) switch (flags)
@ -2015,7 +2015,7 @@ void switch_thread(void)
cores[core].block_task = NULL; cores[core].block_task = NULL;
#if NUM_CORES > 1 #if NUM_CORES > 1
if (thread == block) if (UNLIKELY(thread == block))
{ {
/* This was the last thread running and another core woke us before /* This was the last thread running and another core woke us before
* reaching here. Force next thread selection to give tmo threads or * reaching here. Force next thread selection to give tmo threads or
@ -2040,7 +2040,7 @@ void switch_thread(void)
store_context(&thread->context); store_context(&thread->context);
/* Check if the current thread stack is overflown */ /* Check if the current thread stack is overflown */
if (thread->stack[0] != DEADBEEF) if (UNLIKELY(thread->stack[0] != DEADBEEF))
thread_stkov(thread); thread_stkov(thread);
#if NUM_CORES > 1 #if NUM_CORES > 1
@ -2069,7 +2069,7 @@ void switch_thread(void)
thread = cores[core].running; thread = cores[core].running;
if (thread == NULL) if (UNLIKELY(thread == NULL))
{ {
/* Enter sleep mode to reduce power usage - woken up on interrupt /* Enter sleep mode to reduce power usage - woken up on interrupt
* or wakeup request from another core - expected to enable * or wakeup request from another core - expected to enable
@ -2106,7 +2106,7 @@ void switch_thread(void)
* ready. Of course, aging is only employed when higher and lower * ready. Of course, aging is only employed when higher and lower
* priority threads are runnable. The highest priority runnable * priority threads are runnable. The highest priority runnable
* thread(s) are never skipped. */ * thread(s) are never skipped. */
if (priority <= max || if (LIKELY(priority <= max) ||
IF_NO_SKIP_YIELD( thread->skip_count == -1 || ) IF_NO_SKIP_YIELD( thread->skip_count == -1 || )
(diff = priority - max, ++thread->skip_count > diff*diff)) (diff = priority - max, ++thread->skip_count > diff*diff))
{ {
@ -2733,13 +2733,13 @@ IF_COP( retry_state: )
{ {
ocl = thread->obj_cl; ocl = thread->obj_cl;
if (corelock_try_lock(ocl) == 0) if (UNLIKELY(corelock_try_lock(ocl) == 0))
{ {
UNLOCK_THREAD(thread); UNLOCK_THREAD(thread);
corelock_lock(ocl); corelock_lock(ocl);
LOCK_THREAD(thread); LOCK_THREAD(thread);
if (thread->state != state) if (UNLIKELY(thread->state != state))
{ {
/* Something woke the thread */ /* Something woke the thread */
state = thread->state; state = thread->state;
@ -2873,7 +2873,7 @@ int thread_set_priority(unsigned int thread_id, int priority)
LOCK_THREAD(bl_t); LOCK_THREAD(bl_t);
/* Double-check the owner - retry if it changed */ /* Double-check the owner - retry if it changed */
if (bl->thread == bl_t) if (LIKELY(bl->thread == bl_t))
break; break;
UNLOCK_THREAD(bl_t); UNLOCK_THREAD(bl_t);
@ -2914,7 +2914,7 @@ int thread_set_priority(unsigned int thread_id, int priority)
next = bl->thread; next = bl->thread;
if (next == tstart) if (UNLIKELY(next == tstart))
break; /* Full-circle */ break; /* Full-circle */
UNLOCK_THREAD(thread); UNLOCK_THREAD(thread);