freebsd-dev/sys/kern/subr_taskqueue.c
Andriy Gapon 7107bed0f0 fix loss of taskqueue wakeups (introduced in r300113)
Submitted by:	kmacy
Tested by:	dchagin
2016-05-21 14:51:49 +00:00

1138 lines
27 KiB
C

/*-
* Copyright (c) 2000 Doug Rabson
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/cpuset.h>
#include <sys/interrupt.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/libkern.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sched.h>
#include <sys/smp.h>
#include <sys/taskqueue.h>
#include <sys/unistd.h>
#include <machine/stdarg.h>
static MALLOC_DEFINE(M_TASKQUEUE, "taskqueue", "Task Queues");
static void *taskqueue_giant_ih;
static void *taskqueue_ih;
static void taskqueue_fast_enqueue(void *);
static void taskqueue_swi_enqueue(void *);
static void taskqueue_swi_giant_enqueue(void *);
struct taskqueue_busy {
struct task *tb_running;
TAILQ_ENTRY(taskqueue_busy) tb_link;
};
struct task * const TB_DRAIN_WAITER = (struct task *)0x1;
struct taskqueue {
STAILQ_HEAD(, task) tq_queue;
taskqueue_enqueue_fn tq_enqueue;
void *tq_context;
char *tq_name;
TAILQ_HEAD(, taskqueue_busy) tq_active;
struct mtx tq_mutex;
struct thread **tq_threads;
int tq_tcount;
int tq_spin;
int tq_flags;
int tq_callouts;
taskqueue_callback_fn tq_callbacks[TASKQUEUE_NUM_CALLBACKS];
void *tq_cb_contexts[TASKQUEUE_NUM_CALLBACKS];
};
#define TQ_FLAGS_ACTIVE (1 << 0)
#define TQ_FLAGS_BLOCKED (1 << 1)
#define TQ_FLAGS_UNLOCKED_ENQUEUE (1 << 2)
#define DT_CALLOUT_ARMED (1 << 0)
#define TQ_LOCK(tq) \
do { \
if ((tq)->tq_spin) \
mtx_lock_spin(&(tq)->tq_mutex); \
else \
mtx_lock(&(tq)->tq_mutex); \
} while (0)
#define TQ_ASSERT_LOCKED(tq) mtx_assert(&(tq)->tq_mutex, MA_OWNED)
#define TQ_UNLOCK(tq) \
do { \
if ((tq)->tq_spin) \
mtx_unlock_spin(&(tq)->tq_mutex); \
else \
mtx_unlock(&(tq)->tq_mutex); \
} while (0)
#define TQ_ASSERT_UNLOCKED(tq) mtx_assert(&(tq)->tq_mutex, MA_NOTOWNED)
void
_timeout_task_init(struct taskqueue *queue, struct timeout_task *timeout_task,
int priority, task_fn_t func, void *context)
{
TASK_INIT(&timeout_task->t, priority, func, context);
callout_init_mtx(&timeout_task->c, &queue->tq_mutex,
CALLOUT_RETURNUNLOCKED);
timeout_task->q = queue;
timeout_task->f = 0;
}
static __inline int
TQ_SLEEP(struct taskqueue *tq, void *p, struct mtx *m, int pri, const char *wm,
int t)
{
if (tq->tq_spin)
return (msleep_spin(p, m, wm, t));
return (msleep(p, m, pri, wm, t));
}
static struct taskqueue *
_taskqueue_create(const char *name, int mflags,
taskqueue_enqueue_fn enqueue, void *context,
int mtxflags, const char *mtxname __unused)
{
struct taskqueue *queue;
char *tq_name;
tq_name = malloc(TASKQUEUE_NAMELEN, M_TASKQUEUE, mflags | M_ZERO);
if (!tq_name)
return (NULL);
snprintf(tq_name, TASKQUEUE_NAMELEN, "%s", (name) ? name : "taskqueue");
queue = malloc(sizeof(struct taskqueue), M_TASKQUEUE, mflags | M_ZERO);
if (!queue)
return (NULL);
STAILQ_INIT(&queue->tq_queue);
TAILQ_INIT(&queue->tq_active);
queue->tq_enqueue = enqueue;
queue->tq_context = context;
queue->tq_name = tq_name;
queue->tq_spin = (mtxflags & MTX_SPIN) != 0;
queue->tq_flags |= TQ_FLAGS_ACTIVE;
if (enqueue == taskqueue_fast_enqueue ||
enqueue == taskqueue_swi_enqueue ||
enqueue == taskqueue_swi_giant_enqueue ||
enqueue == taskqueue_thread_enqueue)
queue->tq_flags |= TQ_FLAGS_UNLOCKED_ENQUEUE;
mtx_init(&queue->tq_mutex, tq_name, NULL, mtxflags);
return (queue);
}
struct taskqueue *
taskqueue_create(const char *name, int mflags,
taskqueue_enqueue_fn enqueue, void *context)
{
return _taskqueue_create(name, mflags, enqueue, context,
MTX_DEF, name);
}
void
taskqueue_set_callback(struct taskqueue *queue,
enum taskqueue_callback_type cb_type, taskqueue_callback_fn callback,
void *context)
{
KASSERT(((cb_type >= TASKQUEUE_CALLBACK_TYPE_MIN) &&
(cb_type <= TASKQUEUE_CALLBACK_TYPE_MAX)),
("Callback type %d not valid, must be %d-%d", cb_type,
TASKQUEUE_CALLBACK_TYPE_MIN, TASKQUEUE_CALLBACK_TYPE_MAX));
KASSERT((queue->tq_callbacks[cb_type] == NULL),
("Re-initialization of taskqueue callback?"));
queue->tq_callbacks[cb_type] = callback;
queue->tq_cb_contexts[cb_type] = context;
}
/*
* Signal a taskqueue thread to terminate.
*/
static void
taskqueue_terminate(struct thread **pp, struct taskqueue *tq)
{
while (tq->tq_tcount > 0 || tq->tq_callouts > 0) {
wakeup(tq);
TQ_SLEEP(tq, pp, &tq->tq_mutex, PWAIT, "taskqueue_destroy", 0);
}
}
void
taskqueue_free(struct taskqueue *queue)
{
TQ_LOCK(queue);
queue->tq_flags &= ~TQ_FLAGS_ACTIVE;
taskqueue_terminate(queue->tq_threads, queue);
KASSERT(TAILQ_EMPTY(&queue->tq_active), ("Tasks still running?"));
KASSERT(queue->tq_callouts == 0, ("Armed timeout tasks"));
mtx_destroy(&queue->tq_mutex);
free(queue->tq_threads, M_TASKQUEUE);
free(queue->tq_name, M_TASKQUEUE);
free(queue, M_TASKQUEUE);
}
static int
taskqueue_enqueue_locked(struct taskqueue *queue, struct task *task)
{
struct task *ins;
struct task *prev;
KASSERT(task->ta_func != NULL, ("enqueueing task with NULL func"));
/*
* Count multiple enqueues.
*/
if (task->ta_pending) {
if (task->ta_pending < USHRT_MAX)
task->ta_pending++;
TQ_UNLOCK(queue);
return (0);
}
/*
* Optimise the case when all tasks have the same priority.
*/
prev = STAILQ_LAST(&queue->tq_queue, task, ta_link);
if (!prev || prev->ta_priority >= task->ta_priority) {
STAILQ_INSERT_TAIL(&queue->tq_queue, task, ta_link);
} else {
prev = NULL;
for (ins = STAILQ_FIRST(&queue->tq_queue); ins;
prev = ins, ins = STAILQ_NEXT(ins, ta_link))
if (ins->ta_priority < task->ta_priority)
break;
if (prev)
STAILQ_INSERT_AFTER(&queue->tq_queue, prev, task, ta_link);
else
STAILQ_INSERT_HEAD(&queue->tq_queue, task, ta_link);
}
task->ta_pending = 1;
if ((queue->tq_flags & TQ_FLAGS_UNLOCKED_ENQUEUE) != 0)
TQ_UNLOCK(queue);
if ((queue->tq_flags & TQ_FLAGS_BLOCKED) == 0)
queue->tq_enqueue(queue->tq_context);
if ((queue->tq_flags & TQ_FLAGS_UNLOCKED_ENQUEUE) == 0)
TQ_UNLOCK(queue);
/* Return with lock released. */
return (0);
}
int
grouptaskqueue_enqueue(struct taskqueue *queue, struct task *task)
{
TQ_LOCK(queue);
if (task->ta_pending) {
TQ_UNLOCK(queue);
return (0);
}
STAILQ_INSERT_TAIL(&queue->tq_queue, task, ta_link);
task->ta_pending = 1;
TQ_UNLOCK(queue);
if ((queue->tq_flags & TQ_FLAGS_BLOCKED) == 0)
queue->tq_enqueue(queue->tq_context);
return (0);
}
int
taskqueue_enqueue(struct taskqueue *queue, struct task *task)
{
int res;
TQ_LOCK(queue);
res = taskqueue_enqueue_locked(queue, task);
/* The lock is released inside. */
return (res);
}
static void
taskqueue_timeout_func(void *arg)
{
struct taskqueue *queue;
struct timeout_task *timeout_task;
timeout_task = arg;
queue = timeout_task->q;
KASSERT((timeout_task->f & DT_CALLOUT_ARMED) != 0, ("Stray timeout"));
timeout_task->f &= ~DT_CALLOUT_ARMED;
queue->tq_callouts--;
taskqueue_enqueue_locked(timeout_task->q, &timeout_task->t);
/* The lock is released inside. */
}
int
taskqueue_enqueue_timeout(struct taskqueue *queue,
struct timeout_task *timeout_task, int ticks)
{
int res;
TQ_LOCK(queue);
KASSERT(timeout_task->q == NULL || timeout_task->q == queue,
("Migrated queue"));
KASSERT(!queue->tq_spin, ("Timeout for spin-queue"));
timeout_task->q = queue;
res = timeout_task->t.ta_pending;
if (ticks == 0) {
taskqueue_enqueue_locked(queue, &timeout_task->t);
/* The lock is released inside. */
} else {
if ((timeout_task->f & DT_CALLOUT_ARMED) != 0) {
res++;
} else {
queue->tq_callouts++;
timeout_task->f |= DT_CALLOUT_ARMED;
if (ticks < 0)
ticks = -ticks; /* Ignore overflow. */
}
if (ticks > 0) {
callout_reset(&timeout_task->c, ticks,
taskqueue_timeout_func, timeout_task);
}
TQ_UNLOCK(queue);
}
return (res);
}
static void
taskqueue_task_nop_fn(void *context, int pending)
{
}
/*
* Block until all currently queued tasks in this taskqueue
* have begun execution. Tasks queued during execution of
* this function are ignored.
*/
static void
taskqueue_drain_tq_queue(struct taskqueue *queue)
{
struct task t_barrier;
if (STAILQ_EMPTY(&queue->tq_queue))
return;
/*
* Enqueue our barrier after all current tasks, but with
* the highest priority so that newly queued tasks cannot
* pass it. Because of the high priority, we can not use
* taskqueue_enqueue_locked directly (which drops the lock
* anyway) so just insert it at tail while we have the
* queue lock.
*/
TASK_INIT(&t_barrier, USHRT_MAX, taskqueue_task_nop_fn, &t_barrier);
STAILQ_INSERT_TAIL(&queue->tq_queue, &t_barrier, ta_link);
t_barrier.ta_pending = 1;
/*
* Once the barrier has executed, all previously queued tasks
* have completed or are currently executing.
*/
while (t_barrier.ta_pending != 0)
TQ_SLEEP(queue, &t_barrier, &queue->tq_mutex, PWAIT, "-", 0);
}
/*
* Block until all currently executing tasks for this taskqueue
* complete. Tasks that begin execution during the execution
* of this function are ignored.
*/
static void
taskqueue_drain_tq_active(struct taskqueue *queue)
{
struct taskqueue_busy tb_marker, *tb_first;
if (TAILQ_EMPTY(&queue->tq_active))
return;
/* Block taskq_terminate().*/
queue->tq_callouts++;
/*
* Wait for all currently executing taskqueue threads
* to go idle.
*/
tb_marker.tb_running = TB_DRAIN_WAITER;
TAILQ_INSERT_TAIL(&queue->tq_active, &tb_marker, tb_link);
while (TAILQ_FIRST(&queue->tq_active) != &tb_marker)
TQ_SLEEP(queue, &tb_marker, &queue->tq_mutex, PWAIT, "-", 0);
TAILQ_REMOVE(&queue->tq_active, &tb_marker, tb_link);
/*
* Wakeup any other drain waiter that happened to queue up
* without any intervening active thread.
*/
tb_first = TAILQ_FIRST(&queue->tq_active);
if (tb_first != NULL && tb_first->tb_running == TB_DRAIN_WAITER)
wakeup(tb_first);
/* Release taskqueue_terminate(). */
queue->tq_callouts--;
if ((queue->tq_flags & TQ_FLAGS_ACTIVE) == 0)
wakeup_one(queue->tq_threads);
}
void
taskqueue_block(struct taskqueue *queue)
{
TQ_LOCK(queue);
queue->tq_flags |= TQ_FLAGS_BLOCKED;
TQ_UNLOCK(queue);
}
void
taskqueue_unblock(struct taskqueue *queue)
{
TQ_LOCK(queue);
queue->tq_flags &= ~TQ_FLAGS_BLOCKED;
if (!STAILQ_EMPTY(&queue->tq_queue))
queue->tq_enqueue(queue->tq_context);
TQ_UNLOCK(queue);
}
static void
taskqueue_run_locked(struct taskqueue *queue)
{
struct taskqueue_busy tb;
struct taskqueue_busy *tb_first;
struct task *task;
int pending;
KASSERT(queue != NULL, ("tq is NULL"));
TQ_ASSERT_LOCKED(queue);
tb.tb_running = NULL;
while (STAILQ_FIRST(&queue->tq_queue)) {
TAILQ_INSERT_TAIL(&queue->tq_active, &tb, tb_link);
/*
* Carefully remove the first task from the queue and
* zero its pending count.
*/
task = STAILQ_FIRST(&queue->tq_queue);
KASSERT(task != NULL, ("task is NULL"));
STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link);
pending = task->ta_pending;
task->ta_pending = 0;
tb.tb_running = task;
TQ_UNLOCK(queue);
KASSERT(task->ta_func != NULL, ("task->ta_func is NULL"));
task->ta_func(task->ta_context, pending);
TQ_LOCK(queue);
tb.tb_running = NULL;
wakeup(task);
TAILQ_REMOVE(&queue->tq_active, &tb, tb_link);
tb_first = TAILQ_FIRST(&queue->tq_active);
if (tb_first != NULL &&
tb_first->tb_running == TB_DRAIN_WAITER)
wakeup(tb_first);
}
}
void
taskqueue_run(struct taskqueue *queue)
{
TQ_LOCK(queue);
taskqueue_run_locked(queue);
TQ_UNLOCK(queue);
}
static int
task_is_running(struct taskqueue *queue, struct task *task)
{
struct taskqueue_busy *tb;
TQ_ASSERT_LOCKED(queue);
TAILQ_FOREACH(tb, &queue->tq_active, tb_link) {
if (tb->tb_running == task)
return (1);
}
return (0);
}
static int
taskqueue_cancel_locked(struct taskqueue *queue, struct task *task,
u_int *pendp)
{
if (task->ta_pending > 0)
STAILQ_REMOVE(&queue->tq_queue, task, task, ta_link);
if (pendp != NULL)
*pendp = task->ta_pending;
task->ta_pending = 0;
return (task_is_running(queue, task) ? EBUSY : 0);
}
int
taskqueue_cancel(struct taskqueue *queue, struct task *task, u_int *pendp)
{
int error;
TQ_LOCK(queue);
error = taskqueue_cancel_locked(queue, task, pendp);
TQ_UNLOCK(queue);
return (error);
}
int
taskqueue_cancel_timeout(struct taskqueue *queue,
struct timeout_task *timeout_task, u_int *pendp)
{
u_int pending, pending1;
int error;
TQ_LOCK(queue);
pending = !!(callout_stop(&timeout_task->c) > 0);
error = taskqueue_cancel_locked(queue, &timeout_task->t, &pending1);
if ((timeout_task->f & DT_CALLOUT_ARMED) != 0) {
timeout_task->f &= ~DT_CALLOUT_ARMED;
queue->tq_callouts--;
}
TQ_UNLOCK(queue);
if (pendp != NULL)
*pendp = pending + pending1;
return (error);
}
void
taskqueue_drain(struct taskqueue *queue, struct task *task)
{
if (!queue->tq_spin)
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__);
TQ_LOCK(queue);
while (task->ta_pending != 0 || task_is_running(queue, task))
TQ_SLEEP(queue, task, &queue->tq_mutex, PWAIT, "-", 0);
TQ_UNLOCK(queue);
}
void
taskqueue_drain_all(struct taskqueue *queue)
{
if (!queue->tq_spin)
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__);
TQ_LOCK(queue);
taskqueue_drain_tq_queue(queue);
taskqueue_drain_tq_active(queue);
TQ_UNLOCK(queue);
}
void
taskqueue_drain_timeout(struct taskqueue *queue,
struct timeout_task *timeout_task)
{
callout_drain(&timeout_task->c);
taskqueue_drain(queue, &timeout_task->t);
}
static void
taskqueue_swi_enqueue(void *context)
{
swi_sched(taskqueue_ih, 0);
}
static void
taskqueue_swi_run(void *dummy)
{
taskqueue_run(taskqueue_swi);
}
static void
taskqueue_swi_giant_enqueue(void *context)
{
swi_sched(taskqueue_giant_ih, 0);
}
static void
taskqueue_swi_giant_run(void *dummy)
{
taskqueue_run(taskqueue_swi_giant);
}
static int
_taskqueue_start_threads(struct taskqueue **tqp, int count, int pri,
cpuset_t *mask, const char *name, va_list ap)
{
char ktname[MAXCOMLEN + 1];
struct thread *td;
struct taskqueue *tq;
int i, error;
if (count <= 0)
return (EINVAL);
vsnprintf(ktname, sizeof(ktname), name, ap);
tq = *tqp;
tq->tq_threads = malloc(sizeof(struct thread *) * count, M_TASKQUEUE,
M_NOWAIT | M_ZERO);
if (tq->tq_threads == NULL) {
printf("%s: no memory for %s threads\n", __func__, ktname);
return (ENOMEM);
}
for (i = 0; i < count; i++) {
if (count == 1)
error = kthread_add(taskqueue_thread_loop, tqp, NULL,
&tq->tq_threads[i], RFSTOPPED, 0, "%s", ktname);
else
error = kthread_add(taskqueue_thread_loop, tqp, NULL,
&tq->tq_threads[i], RFSTOPPED, 0,
"%s_%d", ktname, i);
if (error) {
/* should be ok to continue, taskqueue_free will dtrt */
printf("%s: kthread_add(%s): error %d", __func__,
ktname, error);
tq->tq_threads[i] = NULL; /* paranoid */
} else
tq->tq_tcount++;
}
for (i = 0; i < count; i++) {
if (tq->tq_threads[i] == NULL)
continue;
td = tq->tq_threads[i];
if (mask) {
error = cpuset_setthread(td->td_tid, mask);
/*
* Failing to pin is rarely an actual fatal error;
* it'll just affect performance.
*/
if (error)
printf("%s: curthread=%llu: can't pin; "
"error=%d\n",
__func__,
(unsigned long long) td->td_tid,
error);
}
thread_lock(td);
sched_prio(td, pri);
sched_add(td, SRQ_BORING);
thread_unlock(td);
}
return (0);
}
int
taskqueue_start_threads(struct taskqueue **tqp, int count, int pri,
const char *name, ...)
{
va_list ap;
int error;
va_start(ap, name);
error = _taskqueue_start_threads(tqp, count, pri, NULL, name, ap);
va_end(ap);
return (error);
}
int
taskqueue_start_threads_cpuset(struct taskqueue **tqp, int count, int pri,
cpuset_t *mask, const char *name, ...)
{
va_list ap;
int error;
va_start(ap, name);
error = _taskqueue_start_threads(tqp, count, pri, mask, name, ap);
va_end(ap);
return (error);
}
static inline void
taskqueue_run_callback(struct taskqueue *tq,
enum taskqueue_callback_type cb_type)
{
taskqueue_callback_fn tq_callback;
TQ_ASSERT_UNLOCKED(tq);
tq_callback = tq->tq_callbacks[cb_type];
if (tq_callback != NULL)
tq_callback(tq->tq_cb_contexts[cb_type]);
}
void
taskqueue_thread_loop(void *arg)
{
struct taskqueue **tqp, *tq;
tqp = arg;
tq = *tqp;
taskqueue_run_callback(tq, TASKQUEUE_CALLBACK_TYPE_INIT);
TQ_LOCK(tq);
while ((tq->tq_flags & TQ_FLAGS_ACTIVE) != 0) {
/* XXX ? */
taskqueue_run_locked(tq);
/*
* Because taskqueue_run() can drop tq_mutex, we need to
* check if the TQ_FLAGS_ACTIVE flag wasn't removed in the
* meantime, which means we missed a wakeup.
*/
if ((tq->tq_flags & TQ_FLAGS_ACTIVE) == 0)
break;
TQ_SLEEP(tq, tq, &tq->tq_mutex, 0, "-", 0);
}
taskqueue_run_locked(tq);
/*
* This thread is on its way out, so just drop the lock temporarily
* in order to call the shutdown callback. This allows the callback
* to look at the taskqueue, even just before it dies.
*/
TQ_UNLOCK(tq);
taskqueue_run_callback(tq, TASKQUEUE_CALLBACK_TYPE_SHUTDOWN);
TQ_LOCK(tq);
/* rendezvous with thread that asked us to terminate */
tq->tq_tcount--;
wakeup_one(tq->tq_threads);
TQ_UNLOCK(tq);
kthread_exit();
}
void
taskqueue_thread_enqueue(void *context)
{
struct taskqueue **tqp, *tq;
tqp = context;
tq = *tqp;
wakeup_one(tq);
}
TASKQUEUE_DEFINE(swi, taskqueue_swi_enqueue, NULL,
swi_add(NULL, "task queue", taskqueue_swi_run, NULL, SWI_TQ,
INTR_MPSAFE, &taskqueue_ih));
TASKQUEUE_DEFINE(swi_giant, taskqueue_swi_giant_enqueue, NULL,
swi_add(NULL, "Giant taskq", taskqueue_swi_giant_run,
NULL, SWI_TQ_GIANT, 0, &taskqueue_giant_ih));
TASKQUEUE_DEFINE_THREAD(thread);
struct taskqueue *
taskqueue_create_fast(const char *name, int mflags,
taskqueue_enqueue_fn enqueue, void *context)
{
return _taskqueue_create(name, mflags, enqueue, context,
MTX_SPIN, "fast_taskqueue");
}
static void *taskqueue_fast_ih;
static void
taskqueue_fast_enqueue(void *context)
{
swi_sched(taskqueue_fast_ih, 0);
}
static void
taskqueue_fast_run(void *dummy)
{
taskqueue_run(taskqueue_fast);
}
TASKQUEUE_FAST_DEFINE(fast, taskqueue_fast_enqueue, NULL,
swi_add(NULL, "fast taskq", taskqueue_fast_run, NULL,
SWI_TQ_FAST, INTR_MPSAFE, &taskqueue_fast_ih));
int
taskqueue_member(struct taskqueue *queue, struct thread *td)
{
int i, j, ret = 0;
for (i = 0, j = 0; ; i++) {
if (queue->tq_threads[i] == NULL)
continue;
if (queue->tq_threads[i] == td) {
ret = 1;
break;
}
if (++j >= queue->tq_tcount)
break;
}
return (ret);
}
struct taskqgroup_cpu {
LIST_HEAD(, grouptask) tgc_tasks;
struct taskqueue *tgc_taskq;
int tgc_cnt;
int tgc_cpu;
};
struct taskqgroup {
struct taskqgroup_cpu tqg_queue[MAXCPU];
struct mtx tqg_lock;
char * tqg_name;
int tqg_adjusting;
int tqg_stride;
int tqg_cnt;
};
struct taskq_bind_task {
struct task bt_task;
int bt_cpuid;
};
static void
taskqgroup_cpu_create(struct taskqgroup *qgroup, int idx)
{
struct taskqgroup_cpu *qcpu;
qcpu = &qgroup->tqg_queue[idx];
LIST_INIT(&qcpu->tgc_tasks);
qcpu->tgc_taskq = taskqueue_create_fast(NULL, M_WAITOK,
taskqueue_thread_enqueue, &qcpu->tgc_taskq);
taskqueue_start_threads(&qcpu->tgc_taskq, 1, PI_SOFT,
"%s_%d", qgroup->tqg_name, idx);
qcpu->tgc_cpu = idx * qgroup->tqg_stride;
}
static void
taskqgroup_cpu_remove(struct taskqgroup *qgroup, int idx)
{
taskqueue_free(qgroup->tqg_queue[idx].tgc_taskq);
}
/*
* Find the taskq with least # of tasks that doesn't currently have any
* other queues from the uniq identifier.
*/
static int
taskqgroup_find(struct taskqgroup *qgroup, void *uniq)
{
struct grouptask *n;
int i, idx, mincnt;
int strict;
mtx_assert(&qgroup->tqg_lock, MA_OWNED);
if (qgroup->tqg_cnt == 0)
return (0);
idx = -1;
mincnt = INT_MAX;
/*
* Two passes; First scan for a queue with the least tasks that
* does not already service this uniq id. If that fails simply find
* the queue with the least total tasks;
*/
for (strict = 1; mincnt == INT_MAX; strict = 0) {
for (i = 0; i < qgroup->tqg_cnt; i++) {
if (qgroup->tqg_queue[i].tgc_cnt > mincnt)
continue;
if (strict) {
LIST_FOREACH(n,
&qgroup->tqg_queue[i].tgc_tasks, gt_list)
if (n->gt_uniq == uniq)
break;
if (n != NULL)
continue;
}
mincnt = qgroup->tqg_queue[i].tgc_cnt;
idx = i;
}
}
if (idx == -1)
panic("taskqgroup_find: Failed to pick a qid.");
return (idx);
}
void
taskqgroup_attach(struct taskqgroup *qgroup, struct grouptask *gtask,
void *uniq, int irq, char *name)
{
cpuset_t mask;
int qid;
gtask->gt_uniq = uniq;
gtask->gt_name = name;
gtask->gt_irq = irq;
gtask->gt_cpu = -1;
mtx_lock(&qgroup->tqg_lock);
qid = taskqgroup_find(qgroup, uniq);
qgroup->tqg_queue[qid].tgc_cnt++;
LIST_INSERT_HEAD(&qgroup->tqg_queue[qid].tgc_tasks, gtask, gt_list);
gtask->gt_taskqueue = qgroup->tqg_queue[qid].tgc_taskq;
if (irq != -1 && smp_started) {
CPU_ZERO(&mask);
CPU_SET(qgroup->tqg_queue[qid].tgc_cpu, &mask);
mtx_unlock(&qgroup->tqg_lock);
intr_setaffinity(irq, &mask);
} else
mtx_unlock(&qgroup->tqg_lock);
}
int
taskqgroup_attach_cpu(struct taskqgroup *qgroup, struct grouptask *gtask,
void *uniq, int cpu, int irq, char *name)
{
cpuset_t mask;
int i, qid;
qid = -1;
gtask->gt_uniq = uniq;
gtask->gt_name = name;
gtask->gt_irq = irq;
gtask->gt_cpu = cpu;
mtx_lock(&qgroup->tqg_lock);
if (smp_started) {
for (i = 0; i < qgroup->tqg_cnt; i++)
if (qgroup->tqg_queue[i].tgc_cpu == cpu) {
qid = i;
break;
}
if (qid == -1) {
mtx_unlock(&qgroup->tqg_lock);
return (EINVAL);
}
} else
qid = 0;
qgroup->tqg_queue[qid].tgc_cnt++;
LIST_INSERT_HEAD(&qgroup->tqg_queue[qid].tgc_tasks, gtask, gt_list);
gtask->gt_taskqueue = qgroup->tqg_queue[qid].tgc_taskq;
if (irq != -1 && smp_started) {
CPU_ZERO(&mask);
CPU_SET(qgroup->tqg_queue[qid].tgc_cpu, &mask);
mtx_unlock(&qgroup->tqg_lock);
intr_setaffinity(irq, &mask);
} else
mtx_unlock(&qgroup->tqg_lock);
return (0);
}
void
taskqgroup_detach(struct taskqgroup *qgroup, struct grouptask *gtask)
{
int i;
mtx_lock(&qgroup->tqg_lock);
for (i = 0; i < qgroup->tqg_cnt; i++)
if (qgroup->tqg_queue[i].tgc_taskq == gtask->gt_taskqueue)
break;
if (i == qgroup->tqg_cnt)
panic("taskqgroup_detach: task not in group\n");
qgroup->tqg_queue[i].tgc_cnt--;
LIST_REMOVE(gtask, gt_list);
mtx_unlock(&qgroup->tqg_lock);
gtask->gt_taskqueue = NULL;
}
static void
taskqgroup_binder(void *ctx, int pending)
{
struct taskq_bind_task *task = (struct taskq_bind_task *)ctx;
cpuset_t mask;
int error;
CPU_ZERO(&mask);
CPU_SET(task->bt_cpuid, &mask);
error = cpuset_setthread(curthread->td_tid, &mask);
thread_lock(curthread);
sched_bind(curthread, task->bt_cpuid);
thread_unlock(curthread);
if (error)
printf("taskqgroup_binder: setaffinity failed: %d\n",
error);
free(task, M_DEVBUF);
}
static void
taskqgroup_bind(struct taskqgroup *qgroup)
{
struct taskq_bind_task *task;
int i;
/*
* Bind taskqueue threads to specific CPUs, if they have been assigned
* one.
*/
for (i = 0; i < qgroup->tqg_cnt; i++) {
task = malloc(sizeof (*task), M_DEVBUF, M_NOWAIT);
TASK_INIT(&task->bt_task, 0, taskqgroup_binder, task);
task->bt_cpuid = qgroup->tqg_queue[i].tgc_cpu;
taskqueue_enqueue(qgroup->tqg_queue[i].tgc_taskq,
&task->bt_task);
}
}
static int
_taskqgroup_adjust(struct taskqgroup *qgroup, int cnt, int stride)
{
LIST_HEAD(, grouptask) gtask_head = LIST_HEAD_INITIALIZER(NULL);
cpuset_t mask;
struct grouptask *gtask;
int i, old_cnt, qid;
mtx_assert(&qgroup->tqg_lock, MA_OWNED);
if (cnt < 1 || cnt * stride > mp_ncpus || !smp_started) {
printf("taskqgroup_adjust failed cnt: %d stride: %d mp_ncpus: %d smp_started: %d\n",
cnt, stride, mp_ncpus, smp_started);
return (EINVAL);
}
if (qgroup->tqg_adjusting) {
printf("taskqgroup_adjust failed: adjusting\n");
return (EBUSY);
}
qgroup->tqg_adjusting = 1;
old_cnt = qgroup->tqg_cnt;
mtx_unlock(&qgroup->tqg_lock);
/*
* Set up queue for tasks added before boot.
*/
if (old_cnt == 0) {
LIST_SWAP(&gtask_head, &qgroup->tqg_queue[0].tgc_tasks,
grouptask, gt_list);
qgroup->tqg_queue[0].tgc_cnt = 0;
}
/*
* If new taskq threads have been added.
*/
for (i = old_cnt; i < cnt; i++)
taskqgroup_cpu_create(qgroup, i);
mtx_lock(&qgroup->tqg_lock);
qgroup->tqg_cnt = cnt;
qgroup->tqg_stride = stride;
/*
* Adjust drivers to use new taskqs.
*/
for (i = 0; i < old_cnt; i++) {
while ((gtask = LIST_FIRST(&qgroup->tqg_queue[i].tgc_tasks))) {
LIST_REMOVE(gtask, gt_list);
qgroup->tqg_queue[i].tgc_cnt--;
LIST_INSERT_HEAD(&gtask_head, gtask, gt_list);
}
}
while ((gtask = LIST_FIRST(&gtask_head))) {
LIST_REMOVE(gtask, gt_list);
if (gtask->gt_cpu == -1)
qid = taskqgroup_find(qgroup, gtask->gt_uniq);
else {
for (i = 0; i < qgroup->tqg_cnt; i++)
if (qgroup->tqg_queue[i].tgc_cpu == gtask->gt_cpu) {
qid = i;
break;
}
}
qgroup->tqg_queue[qid].tgc_cnt++;
LIST_INSERT_HEAD(&qgroup->tqg_queue[qid].tgc_tasks, gtask,
gt_list);
gtask->gt_taskqueue = qgroup->tqg_queue[qid].tgc_taskq;
}
/*
* Set new CPU and IRQ affinity
*/
for (i = 0; i < cnt; i++) {
qgroup->tqg_queue[i].tgc_cpu = i * qgroup->tqg_stride;
CPU_ZERO(&mask);
CPU_SET(qgroup->tqg_queue[i].tgc_cpu, &mask);
LIST_FOREACH(gtask, &qgroup->tqg_queue[i].tgc_tasks, gt_list) {
if (gtask->gt_irq == -1)
continue;
intr_setaffinity(gtask->gt_irq, &mask);
}
}
mtx_unlock(&qgroup->tqg_lock);
/*
* If taskq thread count has been reduced.
*/
for (i = cnt; i < old_cnt; i++)
taskqgroup_cpu_remove(qgroup, i);
mtx_lock(&qgroup->tqg_lock);
qgroup->tqg_adjusting = 0;
taskqgroup_bind(qgroup);
return (0);
}
int
taskqgroup_adjust(struct taskqgroup *qgroup, int cpu, int stride)
{
int error;
mtx_lock(&qgroup->tqg_lock);
error = _taskqgroup_adjust(qgroup, cpu, stride);
mtx_unlock(&qgroup->tqg_lock);
return (error);
}
struct taskqgroup *
taskqgroup_create(char *name)
{
struct taskqgroup *qgroup;
qgroup = malloc(sizeof(*qgroup), M_TASKQUEUE, M_WAITOK | M_ZERO);
mtx_init(&qgroup->tqg_lock, "taskqgroup", NULL, MTX_DEF);
qgroup->tqg_name = name;
LIST_INIT(&qgroup->tqg_queue[0].tgc_tasks);
return (qgroup);
}
void
taskqgroup_destroy(struct taskqgroup *qgroup)
{
}