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Base scheduler queues off linked lists and do cleanup/consolidation

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Abstracts threading from itself a bit, changes the way its queues are
handled and does type hiding for that as well.

Do alot here due to already required major brain surgery.

Threads may now be on a run queue and a wait queue simultaneously so
that the expired timer only has to wake the thread but not remove it
from the wait queue which simplifies the implicit wake handling.

List formats change for wait queues-- doubly-linked, not circular.
Timeout queue is now singly-linked. The run queue is still circular
as before.

Adds a better thread slot allocator that may keep the slot marked as
used regardless of the thread state. Assists in dumping special tasks
that switch_thread was tasked to perform (blocking tasks).

Deletes alot of code yet surprisingly, gets larger than expected.
Well, I'm not not minding that for the time being-- omlettes and break
a few eggs and all that.

Change-Id: I0834d7bb16b2aecb2f63b58886eeda6ae4f29d59
This commit is contained in:
Michael Sevakis 2014-08-08 06:33:51 -04:00
parent eb63d8b4a2
commit 6ed00870ab
20 changed files with 1550 additions and 2057 deletions
Download patch file Download diff file Expand all files Collapse all files

103
firmware/kernel/mrsw_lock.c
View file

@ -19,7 +19,8 @@
*
****************************************************************************/
#include "kernel-internal.h"
#include "mrsw-lock.h"
#include <string.h>
#include "mrsw_lock.h"
#ifdef HAVE_PRIORITY_SCHEDULING
@ -34,13 +35,14 @@ mrsw_reader_claim(struct mrsw_lock *mrsw, struct thread_entry *current,
static FORCE_INLINE void
mrsw_reader_relinquish(struct mrsw_lock *mrsw, struct thread_entry *current,
int count, unsigned int slotnum)
struct thread_entry *first, int count,
unsigned int slotnum)
{
/* If no writer is queued or has ownership then noone is queued;
if a writer owns it, then the reader would be blocked instead.
Therefore, if the queue has threads, then the next after the
owning readers is a writer and this is not the last reader. */
if (mrsw->queue)
if (first)
corelock_lock(&mrsw->splay.cl);
threadbit_clear_bit(&mrsw->splay.mask, slotnum);
@ -61,10 +63,10 @@ mrsw_reader_relinquish(struct mrsw_lock *mrsw, struct thread_entry *current,
threadbit_popcount(&mrsw->splay.mask));
/* switch owner to sole remaining reader */
slotnum = threadbit_ffs(&mrsw->splay.mask);
mrsw->splay.blocker.thread = thread_id_entry(slotnum);
mrsw->splay.blocker.thread = __thread_slot_entry(slotnum);
}
if (mrsw->queue)
if (first)
{
priority_disinherit(current, &mrsw->splay.blocker);
corelock_unlock(&mrsw->splay.cl);
@ -72,23 +74,25 @@ mrsw_reader_relinquish(struct mrsw_lock *mrsw, struct thread_entry *current,
}
static FORCE_INLINE unsigned int
mrsw_reader_wakeup_writer(struct mrsw_lock *mrsw, unsigned int slotnum)
mrsw_reader_wakeup_writer(struct mrsw_lock *mrsw, struct thread_entry *thread,
unsigned int slotnum)
{
threadbit_clear_bit(&mrsw->splay.mask, slotnum);
return wakeup_thread(&mrsw->queue, WAKEUP_TRANSFER);
return wakeup_thread(thread, WAKEUP_TRANSFER);
}
static FORCE_INLINE unsigned int
mrsw_writer_wakeup_writer(struct mrsw_lock *mrsw)
mrsw_writer_wakeup_writer(struct mrsw_lock *mrsw, struct thread_entry *thread)
{
return wakeup_thread(&mrsw->queue, WAKEUP_TRANSFER);
return wakeup_thread(thread, WAKEUP_TRANSFER);
(void)mrsw;
}
static FORCE_INLINE unsigned int
mrsw_writer_wakeup_readers(struct mrsw_lock *mrsw)
mrsw_writer_wakeup_readers(struct mrsw_lock *mrsw, struct thread_entry *first)
{
unsigned int result = wakeup_thread(&mrsw->queue, WAKEUP_TRANSFER_MULTI);
mrsw->count = thread_self_entry()->retval;
unsigned int result = wakeup_thread(first, WAKEUP_TRANSFER_MULTI);
mrsw->count = __running_self_entry()->retval;
return result;
}
@ -97,32 +101,36 @@ mrsw_writer_wakeup_readers(struct mrsw_lock *mrsw)
#define mrsw_reader_claim(mrsw, current, count, slotnum) \
do {} while (0)
#define mrsw_reader_relinquish(mrsw, current, count, slotnum) \
#define mrsw_reader_relinquish(mrsw, current, first, count, slotnum) \
do {} while (0)
static FORCE_INLINE unsigned int
mrsw_reader_wakeup_writer(struct mrsw_lock *mrsw)
mrsw_reader_wakeup_writer(struct mrsw_lock *mrsw, struct thread_entry *thread)
{
mrsw->splay.blocker.thread = mrsw->queue;
return wakeup_thread(&mrsw->queue);
mrsw->splay.blocker.thread = thread;
return wakeup_thread(thread);
}
static FORCE_INLINE unsigned int
mrsw_writer_wakeup_writer(struct mrsw_lock *mrsw)
mrsw_writer_wakeup_writer(struct mrsw_lock *mrsw, struct thread_entry *thread)
{
mrsw->splay.blocker.thread = mrsw->queue;
return wakeup_thread(&mrsw->queue);
mrsw->splay.blocker.thread = thread;
return wakeup_thread(thread);
}
static FORCE_INLINE unsigned int
mrsw_writer_wakeup_readers(struct mrsw_lock *mrsw)
mrsw_writer_wakeup_readers(struct mrsw_lock *mrsw, struct thread_entry *first)
{
mrsw->splay.blocker.thread = NULL;
int count = 0;
int count = 1;
while (mrsw->queue && mrsw->queue->retval != 0)
while (1)
{
wakeup_thread(&mrsw->queue);
wakeup_thread(first);
if (!(first = WQ_THREAD_FIRST(&mrsw->queue)) || first->retval == 0)
break;
count++;
}
@ -138,14 +146,11 @@ mrsw_writer_wakeup_readers(struct mrsw_lock *mrsw)
void mrsw_init(struct mrsw_lock *mrsw)
{
mrsw->count = 0;
mrsw->queue = NULL;
mrsw->splay.blocker.thread = NULL;
wait_queue_init(&mrsw->queue);
blocker_splay_init(&mrsw->splay);
#ifdef HAVE_PRIORITY_SCHEDULING
mrsw->splay.blocker.priority = PRIORITY_IDLE;
threadbit_clear(&mrsw->splay.mask);
corelock_init(&mrsw->splay.cl);
memset(mrsw->rdrecursion, 0, sizeof (mrsw->rdrecursion));
#endif /* HAVE_PRIORITY_SCHEDULING */
#endif
corelock_init(&mrsw->cl);
}
@ -154,7 +159,7 @@ void mrsw_init(struct mrsw_lock *mrsw)
* access recursively. The current writer is ignored and gets access. */
void mrsw_read_acquire(struct mrsw_lock *mrsw)
{
struct thread_entry *current = thread_self_entry();
struct thread_entry *current = __running_self_entry();
if (current == mrsw->splay.blocker.thread IF_PRIO( && mrsw->count < 0 ))
return; /* Read request while holding write access; pass */
@ -178,7 +183,7 @@ void mrsw_read_acquire(struct mrsw_lock *mrsw)
int count = mrsw->count;
if (LIKELY(count >= 0 && !mrsw->queue))
if (LIKELY(count >= 0 && mrsw->queue.head == NULL))
{
/* Lock open to readers:
IFN_PRIO, mrsw->count tracks reader recursion */
@ -189,13 +194,10 @@ void mrsw_read_acquire(struct mrsw_lock *mrsw)
}
/* A writer owns it or is waiting; block... */
IF_COP( current->obj_cl = &mrsw->cl; )
IF_PRIO( current->blocker = &mrsw->splay.blocker; )
current->bqp = &mrsw->queue;
current->retval = 1; /* indicate multi-wake candidate */
disable_irq();
block_thread(current, TIMEOUT_BLOCK);
block_thread(current, TIMEOUT_BLOCK, &mrsw->queue, &mrsw->splay.blocker);
corelock_unlock(&mrsw->cl);
@ -207,7 +209,7 @@ void mrsw_read_acquire(struct mrsw_lock *mrsw)
* leave opens up access to writer threads. The current writer is ignored. */
void mrsw_read_release(struct mrsw_lock *mrsw)
{
struct thread_entry *current = thread_self_entry();
struct thread_entry *current = __running_self_entry();
if (current == mrsw->splay.blocker.thread IF_PRIO( && mrsw->count < 0 ))
return; /* Read release while holding write access; ignore */
@ -237,17 +239,18 @@ void mrsw_read_release(struct mrsw_lock *mrsw)
unsigned int result = THREAD_NONE;
const int oldlevel = disable_irq_save();
if (--count == 0 && mrsw->queue)
struct thread_entry *thread = WQ_THREAD_FIRST(&mrsw->queue);
if (--count == 0 && thread != NULL)
{
/* No readers remain and a writer is waiting */
mrsw->count = -1;
result = mrsw_reader_wakeup_writer(mrsw IF_PRIO(, slotnum));
result = mrsw_reader_wakeup_writer(mrsw, thread IF_PRIO(, slotnum));
}
else
{
/* Giving up readership; we may be the last, or not */
mrsw->count = count;
mrsw_reader_relinquish(mrsw, current, count, slotnum);
mrsw_reader_relinquish(mrsw, current, thread, count, slotnum);
}
restore_irq(oldlevel);
@ -265,7 +268,7 @@ void mrsw_read_release(struct mrsw_lock *mrsw)
* safely call recursively. */
void mrsw_write_acquire(struct mrsw_lock *mrsw)
{
struct thread_entry *current = thread_self_entry();
struct thread_entry *current = __running_self_entry();
if (current == mrsw->splay.blocker.thread)
{
@ -288,13 +291,10 @@ void mrsw_write_acquire(struct mrsw_lock *mrsw)
}
/* Readers present or a writer owns it - block... */
IF_COP( current->obj_cl = &mrsw->cl; )
IF_PRIO( current->blocker = &mrsw->splay.blocker; )
current->bqp = &mrsw->queue;
current->retval = 0; /* indicate single-wake candidate */
disable_irq();
block_thread(current, TIMEOUT_BLOCK);
block_thread(current, TIMEOUT_BLOCK, &mrsw->queue, &mrsw->splay.blocker);
corelock_unlock(&mrsw->cl);
@ -305,9 +305,9 @@ void mrsw_write_acquire(struct mrsw_lock *mrsw)
/* Release writer thread lock and open the lock to readers and writers */
void mrsw_write_release(struct mrsw_lock *mrsw)
{
KERNEL_ASSERT(thread_self_entry() == mrsw->splay.blocker.thread,
KERNEL_ASSERT(__running_self_entry() == mrsw->splay.blocker.thread,
"mrsw_write_release->wrong thread (%s != %s)\n",
thread_self_entry()->name,
__running_self_entry()->name,
mrsw->splay.blocker.thread->name);
int count = mrsw->count;
@ -323,15 +323,16 @@ void mrsw_write_release(struct mrsw_lock *mrsw)
corelock_lock(&mrsw->cl);
const int oldlevel = disable_irq_save();
if (mrsw->queue == NULL) /* 'count' becomes zero */
struct thread_entry *thread = WQ_THREAD_FIRST(&mrsw->queue);
if (thread == NULL) /* 'count' becomes zero */
{
mrsw->splay.blocker.thread = NULL;
mrsw->count = 0;
}
else if (mrsw->queue->retval == 0) /* 'count' stays -1 */
result = mrsw_writer_wakeup_writer(mrsw);
else /* 'count' becomes # of readers */
result = mrsw_writer_wakeup_readers(mrsw);
else if (thread->retval == 0) /* 'count' stays -1 */
result = mrsw_writer_wakeup_writer(mrsw, thread);
else /* 'count' becomes # of readers */
result = mrsw_writer_wakeup_readers(mrsw, thread);
restore_irq(oldlevel);
corelock_unlock(&mrsw->cl);