freebsd-dev/sys/kern/subr_gtaskqueue.c
Marius Strobl f855ec814d Make taskqgroup_attach{,_cpu}(9) work across architectures
So far, intr_{g,s}etaffinity(9) take a single int for identifying
a device interrupt. This approach doesn't work on all architectures
supported, as a single int isn't sufficient to globally specify a
device interrupt. In particular, with multiple interrupt controllers
in one system as found on e. g. arm and arm64 machines, an interrupt
number as returned by rman_get_start(9) may be only unique relative
to the bus and, thus, interrupt controller, a certain device hangs
off from.
In turn, this makes taskqgroup_attach{,_cpu}(9) and - internal to
the gtaskqueue implementation - taskqgroup_attach_deferred{,_cpu}()
not work across architectures. Yet in turn, iflib(4) as gtaskqueue
consumer so far doesn't fit architectures where interrupt numbers
aren't globally unique.
However, at least for intr_setaffinity(..., CPU_WHICH_IRQ, ...) as
employed by the gtaskqueue implementation to bind an interrupt to a
particular CPU, using bus_bind_intr(9) instead is equivalent from
a functional point of view, with bus_bind_intr(9) taking the device
and interrupt resource arguments required for uniquely specifying a
device interrupt.
Thus, change the gtaskqueue implementation to employ bus_bind_intr(9)
instead and intr_{g,s}etaffinity(9) to take the device and interrupt
resource arguments required respectively. This change also moves
struct grouptask from <sys/_task.h> to <sys/gtaskqueue.h> and wraps
struct gtask along with the gtask_fn_t typedef into #ifdef _KERNEL
as userland likes to include <sys/_task.h> or indirectly drags it
in - for better or worse also with _KERNEL defined -, which with
device_t and struct resource dependencies otherwise is no longer
as easily possible now.
The userland inclusion problem probably can be improved a bit by
introducing a _WANT_TASK (as well as a _WANT_MOUNT) akin to the
existing _WANT_PRISON etc., which is orthogonal to this change,
though, and likely needs an exp-run.

While at it:
- Change the gt_cpu member in the grouptask structure to be of type
  int as used elswhere for specifying CPUs (an int16_t may be too
  narrow sooner or later),
- move the gtaskqueue_enqueue_fn typedef from <sys/gtaskqueue.h> to
  the gtaskqueue implementation as it's only used and needed there,
- change the GTASK_INIT macro to use "gtask" rather than "task" as
  argument given that it actually operates on a struct gtask rather
  than a struct task, and
- let subr_gtaskqueue.c consistently use __func__ to print functions
  names.

Reported by:	mmel
Reviewed by:	mmel
Differential Revision:	https://reviews.freebsd.org/D19139
2019-02-12 21:23:59 +00:00

1061 lines
27 KiB
C

/*-
* Copyright (c) 2000 Doug Rabson
* Copyright (c) 2014 Jeff Roberson
* Copyright (c) 2016 Matthew Macy
* 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/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/gtaskqueue.h>
#include <sys/unistd.h>
#include <machine/stdarg.h>
static MALLOC_DEFINE(M_GTASKQUEUE, "gtaskqueue", "Group Task Queues");
static void gtaskqueue_thread_enqueue(void *);
static void gtaskqueue_thread_loop(void *arg);
static int task_is_running(struct gtaskqueue *queue, struct gtask *gtask);
static void gtaskqueue_drain_locked(struct gtaskqueue *queue, struct gtask *gtask);
TASKQGROUP_DEFINE(softirq, mp_ncpus, 1);
TASKQGROUP_DEFINE(config, 1, 1);
struct gtaskqueue_busy {
struct gtask *tb_running;
TAILQ_ENTRY(gtaskqueue_busy) tb_link;
};
static struct gtask * const TB_DRAIN_WAITER = (struct gtask *)0x1;
typedef void (*gtaskqueue_enqueue_fn)(void *context);
struct gtaskqueue {
STAILQ_HEAD(, gtask) tq_queue;
gtaskqueue_enqueue_fn tq_enqueue;
void *tq_context;
char *tq_name;
TAILQ_HEAD(, gtaskqueue_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)
#ifdef INVARIANTS
static void
gtask_dump(struct gtask *gtask)
{
printf("gtask: %p ta_flags=%x ta_priority=%d ta_func=%p ta_context=%p\n",
gtask, gtask->ta_flags, gtask->ta_priority, gtask->ta_func, gtask->ta_context);
}
#endif
static __inline int
TQ_SLEEP(struct gtaskqueue *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 gtaskqueue *
_gtaskqueue_create(const char *name, int mflags,
taskqueue_enqueue_fn enqueue, void *context,
int mtxflags, const char *mtxname __unused)
{
struct gtaskqueue *queue;
char *tq_name;
tq_name = malloc(TASKQUEUE_NAMELEN, M_GTASKQUEUE, mflags | M_ZERO);
if (!tq_name)
return (NULL);
snprintf(tq_name, TASKQUEUE_NAMELEN, "%s", (name) ? name : "taskqueue");
queue = malloc(sizeof(struct gtaskqueue), M_GTASKQUEUE, mflags | M_ZERO);
if (!queue) {
free(tq_name, M_GTASKQUEUE);
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 == gtaskqueue_thread_enqueue)
queue->tq_flags |= TQ_FLAGS_UNLOCKED_ENQUEUE;
mtx_init(&queue->tq_mutex, tq_name, NULL, mtxflags);
return (queue);
}
/*
* Signal a taskqueue thread to terminate.
*/
static void
gtaskqueue_terminate(struct thread **pp, struct gtaskqueue *tq)
{
while (tq->tq_tcount > 0 || tq->tq_callouts > 0) {
wakeup(tq);
TQ_SLEEP(tq, pp, &tq->tq_mutex, PWAIT, "taskqueue_destroy", 0);
}
}
static void
gtaskqueue_free(struct gtaskqueue *queue)
{
TQ_LOCK(queue);
queue->tq_flags &= ~TQ_FLAGS_ACTIVE;
gtaskqueue_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_GTASKQUEUE);
free(queue->tq_name, M_GTASKQUEUE);
free(queue, M_GTASKQUEUE);
}
/*
* Wait for all to complete, then prevent it from being enqueued
*/
void
grouptask_block(struct grouptask *grouptask)
{
struct gtaskqueue *queue = grouptask->gt_taskqueue;
struct gtask *gtask = &grouptask->gt_task;
#ifdef INVARIANTS
if (queue == NULL) {
gtask_dump(gtask);
panic("queue == NULL");
}
#endif
TQ_LOCK(queue);
gtask->ta_flags |= TASK_NOENQUEUE;
gtaskqueue_drain_locked(queue, gtask);
TQ_UNLOCK(queue);
}
void
grouptask_unblock(struct grouptask *grouptask)
{
struct gtaskqueue *queue = grouptask->gt_taskqueue;
struct gtask *gtask = &grouptask->gt_task;
#ifdef INVARIANTS
if (queue == NULL) {
gtask_dump(gtask);
panic("queue == NULL");
}
#endif
TQ_LOCK(queue);
gtask->ta_flags &= ~TASK_NOENQUEUE;
TQ_UNLOCK(queue);
}
int
grouptaskqueue_enqueue(struct gtaskqueue *queue, struct gtask *gtask)
{
#ifdef INVARIANTS
if (queue == NULL) {
gtask_dump(gtask);
panic("queue == NULL");
}
#endif
TQ_LOCK(queue);
if (gtask->ta_flags & TASK_ENQUEUED) {
TQ_UNLOCK(queue);
return (0);
}
if (gtask->ta_flags & TASK_NOENQUEUE) {
TQ_UNLOCK(queue);
return (EAGAIN);
}
STAILQ_INSERT_TAIL(&queue->tq_queue, gtask, ta_link);
gtask->ta_flags |= TASK_ENQUEUED;
TQ_UNLOCK(queue);
if ((queue->tq_flags & TQ_FLAGS_BLOCKED) == 0)
queue->tq_enqueue(queue->tq_context);
return (0);
}
static void
gtaskqueue_task_nop_fn(void *context)
{
}
/*
* Block until all currently queued tasks in this taskqueue
* have begun execution. Tasks queued during execution of
* this function are ignored.
*/
static void
gtaskqueue_drain_tq_queue(struct gtaskqueue *queue)
{
struct gtask 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.
*/
GTASK_INIT(&t_barrier, 0, USHRT_MAX, gtaskqueue_task_nop_fn, &t_barrier);
STAILQ_INSERT_TAIL(&queue->tq_queue, &t_barrier, ta_link);
t_barrier.ta_flags |= TASK_ENQUEUED;
/*
* Once the barrier has executed, all previously queued tasks
* have completed or are currently executing.
*/
while (t_barrier.ta_flags & TASK_ENQUEUED)
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
gtaskqueue_drain_tq_active(struct gtaskqueue *queue)
{
struct gtaskqueue_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
gtaskqueue_block(struct gtaskqueue *queue)
{
TQ_LOCK(queue);
queue->tq_flags |= TQ_FLAGS_BLOCKED;
TQ_UNLOCK(queue);
}
void
gtaskqueue_unblock(struct gtaskqueue *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
gtaskqueue_run_locked(struct gtaskqueue *queue)
{
struct gtaskqueue_busy tb;
struct gtaskqueue_busy *tb_first;
struct gtask *gtask;
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
* clear its TASK_ENQUEUED flag
*/
gtask = STAILQ_FIRST(&queue->tq_queue);
KASSERT(gtask != NULL, ("task is NULL"));
STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link);
gtask->ta_flags &= ~TASK_ENQUEUED;
tb.tb_running = gtask;
TQ_UNLOCK(queue);
KASSERT(gtask->ta_func != NULL, ("task->ta_func is NULL"));
gtask->ta_func(gtask->ta_context);
TQ_LOCK(queue);
tb.tb_running = NULL;
wakeup(gtask);
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);
}
}
static int
task_is_running(struct gtaskqueue *queue, struct gtask *gtask)
{
struct gtaskqueue_busy *tb;
TQ_ASSERT_LOCKED(queue);
TAILQ_FOREACH(tb, &queue->tq_active, tb_link) {
if (tb->tb_running == gtask)
return (1);
}
return (0);
}
static int
gtaskqueue_cancel_locked(struct gtaskqueue *queue, struct gtask *gtask)
{
if (gtask->ta_flags & TASK_ENQUEUED)
STAILQ_REMOVE(&queue->tq_queue, gtask, gtask, ta_link);
gtask->ta_flags &= ~TASK_ENQUEUED;
return (task_is_running(queue, gtask) ? EBUSY : 0);
}
int
gtaskqueue_cancel(struct gtaskqueue *queue, struct gtask *gtask)
{
int error;
TQ_LOCK(queue);
error = gtaskqueue_cancel_locked(queue, gtask);
TQ_UNLOCK(queue);
return (error);
}
static void
gtaskqueue_drain_locked(struct gtaskqueue *queue, struct gtask *gtask)
{
while ((gtask->ta_flags & TASK_ENQUEUED) || task_is_running(queue, gtask))
TQ_SLEEP(queue, gtask, &queue->tq_mutex, PWAIT, "-", 0);
}
void
gtaskqueue_drain(struct gtaskqueue *queue, struct gtask *gtask)
{
if (!queue->tq_spin)
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__);
TQ_LOCK(queue);
gtaskqueue_drain_locked(queue, gtask);
TQ_UNLOCK(queue);
}
void
gtaskqueue_drain_all(struct gtaskqueue *queue)
{
if (!queue->tq_spin)
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__);
TQ_LOCK(queue);
gtaskqueue_drain_tq_queue(queue);
gtaskqueue_drain_tq_active(queue);
TQ_UNLOCK(queue);
}
static int
_gtaskqueue_start_threads(struct gtaskqueue **tqp, int count, int pri,
cpuset_t *mask, const char *name, va_list ap)
{
char ktname[MAXCOMLEN + 1];
struct thread *td;
struct gtaskqueue *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_GTASKQUEUE,
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(gtaskqueue_thread_loop, tqp, NULL,
&tq->tq_threads[i], RFSTOPPED, 0, "%s", ktname);
else
error = kthread_add(gtaskqueue_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);
}
static int
gtaskqueue_start_threads(struct gtaskqueue **tqp, int count, int pri,
const char *name, ...)
{
va_list ap;
int error;
va_start(ap, name);
error = _gtaskqueue_start_threads(tqp, count, pri, NULL, name, ap);
va_end(ap);
return (error);
}
static inline void
gtaskqueue_run_callback(struct gtaskqueue *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]);
}
static void
gtaskqueue_thread_loop(void *arg)
{
struct gtaskqueue **tqp, *tq;
tqp = arg;
tq = *tqp;
gtaskqueue_run_callback(tq, TASKQUEUE_CALLBACK_TYPE_INIT);
TQ_LOCK(tq);
while ((tq->tq_flags & TQ_FLAGS_ACTIVE) != 0) {
/* XXX ? */
gtaskqueue_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);
}
gtaskqueue_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);
gtaskqueue_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();
}
static void
gtaskqueue_thread_enqueue(void *context)
{
struct gtaskqueue **tqp, *tq;
tqp = context;
tq = *tqp;
wakeup_one(tq);
}
static struct gtaskqueue *
gtaskqueue_create_fast(const char *name, int mflags,
taskqueue_enqueue_fn enqueue, void *context)
{
return _gtaskqueue_create(name, mflags, enqueue, context,
MTX_SPIN, "fast_taskqueue");
}
struct taskqgroup_cpu {
LIST_HEAD(, grouptask) tgc_tasks;
struct gtaskqueue *tgc_taskq;
int tgc_cnt;
int tgc_cpu;
};
struct taskqgroup {
struct taskqgroup_cpu tqg_queue[MAXCPU];
struct mtx tqg_lock;
const char * tqg_name;
int tqg_adjusting;
int tqg_stride;
int tqg_cnt;
};
struct taskq_bind_task {
struct gtask bt_task;
int bt_cpuid;
};
static void
taskqgroup_cpu_create(struct taskqgroup *qgroup, int idx, int cpu)
{
struct taskqgroup_cpu *qcpu;
qcpu = &qgroup->tqg_queue[idx];
LIST_INIT(&qcpu->tgc_tasks);
qcpu->tgc_taskq = gtaskqueue_create_fast(NULL, M_WAITOK,
taskqueue_thread_enqueue, &qcpu->tgc_taskq);
gtaskqueue_start_threads(&qcpu->tgc_taskq, 1, PI_SOFT,
"%s_%d", qgroup->tqg_name, idx);
qcpu->tgc_cpu = cpu;
}
static void
taskqgroup_cpu_remove(struct taskqgroup *qgroup, int idx)
{
gtaskqueue_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("%s: failed to pick a qid.", __func__);
return (idx);
}
/*
* smp_started is unusable since it is not set for UP kernels or even for
* SMP kernels when there is 1 CPU. This is usually handled by adding a
* (mp_ncpus == 1) test, but that would be broken here since we need to
* to synchronize with the SI_SUB_SMP ordering. Even in the pure SMP case
* smp_started only gives a fuzzy ordering relative to SI_SUB_SMP.
*
* So maintain our own flag. It must be set after all CPUs are started
* and before SI_SUB_SMP:SI_ORDER_ANY so that the SYSINIT for delayed
* adjustment is properly delayed. SI_ORDER_FOURTH is clearly before
* SI_ORDER_ANY and unclearly after the CPUs are started. It would be
* simpler for adjustment to pass a flag indicating if it is delayed.
*/
static int tqg_smp_started;
static void
tqg_record_smp_started(void *arg)
{
tqg_smp_started = 1;
}
SYSINIT(tqg_record_smp_started, SI_SUB_SMP, SI_ORDER_FOURTH,
tqg_record_smp_started, NULL);
void
taskqgroup_attach(struct taskqgroup *qgroup, struct grouptask *gtask,
void *uniq, device_t dev, struct resource *irq, const char *name)
{
int cpu, qid, error;
gtask->gt_uniq = uniq;
snprintf(gtask->gt_name, GROUPTASK_NAMELEN, "%s", name ? name : "grouptask");
gtask->gt_dev = dev;
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 (dev != NULL && irq != NULL && tqg_smp_started) {
cpu = qgroup->tqg_queue[qid].tgc_cpu;
gtask->gt_cpu = cpu;
mtx_unlock(&qgroup->tqg_lock);
error = bus_bind_intr(dev, irq, cpu);
if (error)
printf("%s: binding interrupt failed for %s: %d\n",
__func__, gtask->gt_name, error);
} else
mtx_unlock(&qgroup->tqg_lock);
}
static void
taskqgroup_attach_deferred(struct taskqgroup *qgroup, struct grouptask *gtask)
{
int qid, cpu, error;
mtx_lock(&qgroup->tqg_lock);
qid = taskqgroup_find(qgroup, gtask->gt_uniq);
cpu = qgroup->tqg_queue[qid].tgc_cpu;
if (gtask->gt_dev != NULL && gtask->gt_irq != NULL) {
mtx_unlock(&qgroup->tqg_lock);
error = bus_bind_intr(gtask->gt_dev, gtask->gt_irq, cpu);
mtx_lock(&qgroup->tqg_lock);
if (error)
printf("%s: binding interrupt failed for %s: %d\n",
__func__, gtask->gt_name, error);
}
qgroup->tqg_queue[qid].tgc_cnt++;
LIST_INSERT_HEAD(&qgroup->tqg_queue[qid].tgc_tasks, gtask, gt_list);
MPASS(qgroup->tqg_queue[qid].tgc_taskq != NULL);
gtask->gt_taskqueue = qgroup->tqg_queue[qid].tgc_taskq;
mtx_unlock(&qgroup->tqg_lock);
}
int
taskqgroup_attach_cpu(struct taskqgroup *qgroup, struct grouptask *gtask,
void *uniq, int cpu, device_t dev, struct resource *irq, const char *name)
{
int i, qid, error;
qid = -1;
gtask->gt_uniq = uniq;
snprintf(gtask->gt_name, GROUPTASK_NAMELEN, "%s", name ? name : "grouptask");
gtask->gt_dev = dev;
gtask->gt_irq = irq;
gtask->gt_cpu = cpu;
mtx_lock(&qgroup->tqg_lock);
if (tqg_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);
printf("%s: qid not found for %s cpu=%d\n", __func__, gtask->gt_name, cpu);
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;
cpu = qgroup->tqg_queue[qid].tgc_cpu;
mtx_unlock(&qgroup->tqg_lock);
if (dev != NULL && irq != NULL && tqg_smp_started) {
error = bus_bind_intr(dev, irq, cpu);
if (error)
printf("%s: binding interrupt failed for %s: %d\n",
__func__, gtask->gt_name, error);
}
return (0);
}
static int
taskqgroup_attach_cpu_deferred(struct taskqgroup *qgroup, struct grouptask *gtask)
{
device_t dev;
struct resource *irq;
int cpu, error, i, qid;
qid = -1;
dev = gtask->gt_dev;
irq = gtask->gt_irq;
cpu = gtask->gt_cpu;
MPASS(tqg_smp_started);
mtx_lock(&qgroup->tqg_lock);
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);
printf("%s: qid not found for %s cpu=%d\n", __func__, gtask->gt_name, cpu);
return (EINVAL);
}
qgroup->tqg_queue[qid].tgc_cnt++;
LIST_INSERT_HEAD(&qgroup->tqg_queue[qid].tgc_tasks, gtask, gt_list);
MPASS(qgroup->tqg_queue[qid].tgc_taskq != NULL);
gtask->gt_taskqueue = qgroup->tqg_queue[qid].tgc_taskq;
mtx_unlock(&qgroup->tqg_lock);
if (dev != NULL && irq != NULL) {
error = bus_bind_intr(dev, irq, cpu);
if (error)
printf("%s: binding interrupt failed for %s: %d\n",
__func__, gtask->gt_name, error);
}
return (0);
}
void
taskqgroup_detach(struct taskqgroup *qgroup, struct grouptask *gtask)
{
int i;
grouptask_block(gtask);
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("%s: task %s not in group", __func__, gtask->gt_name);
qgroup->tqg_queue[i].tgc_cnt--;
LIST_REMOVE(gtask, gt_list);
mtx_unlock(&qgroup->tqg_lock);
gtask->gt_taskqueue = NULL;
gtask->gt_task.ta_flags &= ~TASK_NOENQUEUE;
}
static void
taskqgroup_binder(void *ctx)
{
struct taskq_bind_task *gtask = (struct taskq_bind_task *)ctx;
cpuset_t mask;
int error;
CPU_ZERO(&mask);
CPU_SET(gtask->bt_cpuid, &mask);
error = cpuset_setthread(curthread->td_tid, &mask);
thread_lock(curthread);
sched_bind(curthread, gtask->bt_cpuid);
thread_unlock(curthread);
if (error)
printf("%s: binding curthread failed: %d\n", __func__, error);
free(gtask, M_DEVBUF);
}
static void
taskqgroup_bind(struct taskqgroup *qgroup)
{
struct taskq_bind_task *gtask;
int i;
/*
* Bind taskqueue threads to specific CPUs, if they have been assigned
* one.
*/
if (qgroup->tqg_cnt == 1)
return;
for (i = 0; i < qgroup->tqg_cnt; i++) {
gtask = malloc(sizeof (*gtask), M_DEVBUF, M_WAITOK);
GTASK_INIT(&gtask->bt_task, 0, 0, taskqgroup_binder, gtask);
gtask->bt_cpuid = qgroup->tqg_queue[i].tgc_cpu;
grouptaskqueue_enqueue(qgroup->tqg_queue[i].tgc_taskq,
&gtask->bt_task);
}
}
static void
taskqgroup_config_init(void *arg)
{
struct taskqgroup *qgroup = qgroup_config;
LIST_HEAD(, grouptask) gtask_head = LIST_HEAD_INITIALIZER(NULL);
LIST_SWAP(&gtask_head, &qgroup->tqg_queue[0].tgc_tasks,
grouptask, gt_list);
qgroup->tqg_queue[0].tgc_cnt = 0;
taskqgroup_cpu_create(qgroup, 0, 0);
qgroup->tqg_cnt = 1;
qgroup->tqg_stride = 1;
}
SYSINIT(taskqgroup_config_init, SI_SUB_TASKQ, SI_ORDER_SECOND,
taskqgroup_config_init, NULL);
static int
_taskqgroup_adjust(struct taskqgroup *qgroup, int cnt, int stride)
{
LIST_HEAD(, grouptask) gtask_head = LIST_HEAD_INITIALIZER(NULL);
struct grouptask *gtask;
int i, k, old_cnt, old_cpu, cpu;
mtx_assert(&qgroup->tqg_lock, MA_OWNED);
if (cnt < 1 || cnt * stride > mp_ncpus || !tqg_smp_started) {
printf("%s: failed cnt: %d stride: %d "
"mp_ncpus: %d tqg_smp_started: %d\n",
__func__, cnt, stride, mp_ncpus, tqg_smp_started);
return (EINVAL);
}
if (qgroup->tqg_adjusting) {
printf("%s failed: adjusting\n", __func__);
return (EBUSY);
}
qgroup->tqg_adjusting = 1;
old_cnt = qgroup->tqg_cnt;
old_cpu = 0;
if (old_cnt < cnt)
old_cpu = qgroup->tqg_queue[old_cnt].tgc_cpu;
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.
*/
cpu = old_cpu;
for (i = old_cnt; i < cnt; i++) {
taskqgroup_cpu_create(qgroup, i, cpu);
for (k = 0; k < stride; k++)
cpu = CPU_NEXT(cpu);
}
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);
}
}
mtx_unlock(&qgroup->tqg_lock);
while ((gtask = LIST_FIRST(&gtask_head))) {
LIST_REMOVE(gtask, gt_list);
if (gtask->gt_cpu == -1)
taskqgroup_attach_deferred(qgroup, gtask);
else if (taskqgroup_attach_cpu_deferred(qgroup, gtask))
taskqgroup_attach_deferred(qgroup, gtask);
}
#ifdef INVARIANTS
mtx_lock(&qgroup->tqg_lock);
for (i = 0; i < qgroup->tqg_cnt; i++) {
MPASS(qgroup->tqg_queue[i].tgc_taskq != NULL);
LIST_FOREACH(gtask, &qgroup->tqg_queue[i].tgc_tasks, gt_list)
MPASS(gtask->gt_taskqueue != NULL);
}
mtx_unlock(&qgroup->tqg_lock);
#endif
/*
* If taskq thread count has been reduced.
*/
for (i = cnt; i < old_cnt; i++)
taskqgroup_cpu_remove(qgroup, i);
taskqgroup_bind(qgroup);
mtx_lock(&qgroup->tqg_lock);
qgroup->tqg_adjusting = 0;
return (0);
}
int
taskqgroup_adjust(struct taskqgroup *qgroup, int cnt, int stride)
{
int error;
mtx_lock(&qgroup->tqg_lock);
error = _taskqgroup_adjust(qgroup, cnt, stride);
mtx_unlock(&qgroup->tqg_lock);
return (error);
}
struct taskqgroup *
taskqgroup_create(const char *name)
{
struct taskqgroup *qgroup;
qgroup = malloc(sizeof(*qgroup), M_GTASKQUEUE, 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)
{
}
void
taskqgroup_config_gtask_init(void *ctx, struct grouptask *gtask, gtask_fn_t *fn,
const char *name)
{
GROUPTASK_INIT(gtask, 0, fn, ctx);
taskqgroup_attach(qgroup_config, gtask, gtask, NULL, NULL, name);
}
void
taskqgroup_config_gtask_deinit(struct grouptask *gtask)
{
taskqgroup_detach(qgroup_config, gtask);
}