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-rw-r--r--fs/io-wq.c449
1 files changed, 276 insertions, 173 deletions
diff --git a/fs/io-wq.c b/fs/io-wq.c
index cd9bd095fb1b..c2360cdc403d 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -14,6 +14,7 @@
#include <linux/rculist_nulls.h>
#include <linux/cpu.h>
#include <linux/tracehook.h>
+#include <uapi/linux/io_uring.h>
#include "io-wq.h"
@@ -23,8 +24,7 @@ enum {
IO_WORKER_F_UP = 1, /* up and active */
IO_WORKER_F_RUNNING = 2, /* account as running */
IO_WORKER_F_FREE = 4, /* worker on free list */
- IO_WORKER_F_FIXED = 8, /* static idle worker */
- IO_WORKER_F_BOUND = 16, /* is doing bounded work */
+ IO_WORKER_F_BOUND = 8, /* is doing bounded work */
};
enum {
@@ -32,7 +32,7 @@ enum {
};
enum {
- IO_WQE_FLAG_STALLED = 1, /* stalled on hash */
+ IO_ACCT_STALLED_BIT = 0, /* stalled on hash */
};
/*
@@ -55,7 +55,10 @@ struct io_worker {
struct callback_head create_work;
int create_index;
- struct rcu_head rcu;
+ union {
+ struct rcu_head rcu;
+ struct work_struct work;
+ };
};
#if BITS_PER_LONG == 64
@@ -71,25 +74,24 @@ struct io_wqe_acct {
unsigned max_workers;
int index;
atomic_t nr_running;
+ struct io_wq_work_list work_list;
+ unsigned long flags;
};
enum {
IO_WQ_ACCT_BOUND,
IO_WQ_ACCT_UNBOUND,
+ IO_WQ_ACCT_NR,
};
/*
* Per-node worker thread pool
*/
struct io_wqe {
- struct {
- raw_spinlock_t lock;
- struct io_wq_work_list work_list;
- unsigned flags;
- } ____cacheline_aligned_in_smp;
+ raw_spinlock_t lock;
+ struct io_wqe_acct acct[2];
int node;
- struct io_wqe_acct acct[2];
struct hlist_nulls_head free_list;
struct list_head all_list;
@@ -133,8 +135,11 @@ struct io_cb_cancel_data {
bool cancel_all;
};
-static void create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index, bool first);
+static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index);
static void io_wqe_dec_running(struct io_worker *worker);
+static bool io_acct_cancel_pending_work(struct io_wqe *wqe,
+ struct io_wqe_acct *acct,
+ struct io_cb_cancel_data *match);
static bool io_worker_get(struct io_worker *worker)
{
@@ -172,7 +177,6 @@ static void io_worker_ref_put(struct io_wq *wq)
static void io_worker_exit(struct io_worker *worker)
{
struct io_wqe *wqe = worker->wqe;
- struct io_wqe_acct *acct = io_wqe_get_acct(worker);
if (refcount_dec_and_test(&worker->ref))
complete(&worker->ref_done);
@@ -182,7 +186,6 @@ static void io_worker_exit(struct io_worker *worker)
if (worker->flags & IO_WORKER_F_FREE)
hlist_nulls_del_rcu(&worker->nulls_node);
list_del_rcu(&worker->all_list);
- acct->nr_workers--;
preempt_disable();
io_wqe_dec_running(worker);
worker->flags = 0;
@@ -195,11 +198,10 @@ static void io_worker_exit(struct io_worker *worker)
do_exit(0);
}
-static inline bool io_wqe_run_queue(struct io_wqe *wqe)
- __must_hold(wqe->lock)
+static inline bool io_acct_run_queue(struct io_wqe_acct *acct)
{
- if (!wq_list_empty(&wqe->work_list) &&
- !(wqe->flags & IO_WQE_FLAG_STALLED))
+ if (!wq_list_empty(&acct->work_list) &&
+ !test_bit(IO_ACCT_STALLED_BIT, &acct->flags))
return true;
return false;
}
@@ -208,7 +210,8 @@ static inline bool io_wqe_run_queue(struct io_wqe *wqe)
* Check head of free list for an available worker. If one isn't available,
* caller must create one.
*/
-static bool io_wqe_activate_free_worker(struct io_wqe *wqe)
+static bool io_wqe_activate_free_worker(struct io_wqe *wqe,
+ struct io_wqe_acct *acct)
__must_hold(RCU)
{
struct hlist_nulls_node *n;
@@ -222,6 +225,10 @@ static bool io_wqe_activate_free_worker(struct io_wqe *wqe)
hlist_nulls_for_each_entry_rcu(worker, n, &wqe->free_list, nulls_node) {
if (!io_worker_get(worker))
continue;
+ if (io_wqe_get_acct(worker) != acct) {
+ io_worker_release(worker);
+ continue;
+ }
if (wake_up_process(worker->task)) {
io_worker_release(worker);
return true;
@@ -236,10 +243,8 @@ static bool io_wqe_activate_free_worker(struct io_wqe *wqe)
* We need a worker. If we find a free one, we're good. If not, and we're
* below the max number of workers, create one.
*/
-static void io_wqe_wake_worker(struct io_wqe *wqe, struct io_wqe_acct *acct)
+static bool io_wqe_create_worker(struct io_wqe *wqe, struct io_wqe_acct *acct)
{
- bool ret;
-
/*
* Most likely an attempt to queue unbounded work on an io_wq that
* wasn't setup with any unbounded workers.
@@ -247,27 +252,16 @@ static void io_wqe_wake_worker(struct io_wqe *wqe, struct io_wqe_acct *acct)
if (unlikely(!acct->max_workers))
pr_warn_once("io-wq is not configured for unbound workers");
- rcu_read_lock();
- ret = io_wqe_activate_free_worker(wqe);
- rcu_read_unlock();
-
- if (!ret) {
- bool do_create = false, first = false;
-
- raw_spin_lock(&wqe->lock);
- if (acct->nr_workers < acct->max_workers) {
- if (!acct->nr_workers)
- first = true;
- acct->nr_workers++;
- do_create = true;
- }
+ raw_spin_lock(&wqe->lock);
+ if (acct->nr_workers == acct->max_workers) {
raw_spin_unlock(&wqe->lock);
- if (do_create) {
- atomic_inc(&acct->nr_running);
- atomic_inc(&wqe->wq->worker_refs);
- create_io_worker(wqe->wq, wqe, acct->index, first);
- }
+ return true;
}
+ acct->nr_workers++;
+ raw_spin_unlock(&wqe->lock);
+ atomic_inc(&acct->nr_running);
+ atomic_inc(&wqe->wq->worker_refs);
+ return create_io_worker(wqe->wq, wqe, acct->index);
}
static void io_wqe_inc_running(struct io_worker *worker)
@@ -283,7 +277,7 @@ static void create_worker_cb(struct callback_head *cb)
struct io_wq *wq;
struct io_wqe *wqe;
struct io_wqe_acct *acct;
- bool do_create = false, first = false;
+ bool do_create = false;
worker = container_of(cb, struct io_worker, create_work);
wqe = worker->wqe;
@@ -291,14 +285,12 @@ static void create_worker_cb(struct callback_head *cb)
acct = &wqe->acct[worker->create_index];
raw_spin_lock(&wqe->lock);
if (acct->nr_workers < acct->max_workers) {
- if (!acct->nr_workers)
- first = true;
acct->nr_workers++;
do_create = true;
}
raw_spin_unlock(&wqe->lock);
if (do_create) {
- create_io_worker(wq, wqe, worker->create_index, first);
+ create_io_worker(wq, wqe, worker->create_index);
} else {
atomic_dec(&acct->nr_running);
io_worker_ref_put(wq);
@@ -307,9 +299,11 @@ static void create_worker_cb(struct callback_head *cb)
io_worker_release(worker);
}
-static void io_queue_worker_create(struct io_wqe *wqe, struct io_worker *worker,
- struct io_wqe_acct *acct)
+static bool io_queue_worker_create(struct io_worker *worker,
+ struct io_wqe_acct *acct,
+ task_work_func_t func)
{
+ struct io_wqe *wqe = worker->wqe;
struct io_wq *wq = wqe->wq;
/* raced with exit, just ignore create call */
@@ -327,16 +321,17 @@ static void io_queue_worker_create(struct io_wqe *wqe, struct io_worker *worker,
test_and_set_bit_lock(0, &worker->create_state))
goto fail_release;
- init_task_work(&worker->create_work, create_worker_cb);
+ init_task_work(&worker->create_work, func);
worker->create_index = acct->index;
if (!task_work_add(wq->task, &worker->create_work, TWA_SIGNAL))
- return;
+ return true;
clear_bit_unlock(0, &worker->create_state);
fail_release:
io_worker_release(worker);
fail:
atomic_dec(&acct->nr_running);
io_worker_ref_put(wq);
+ return false;
}
static void io_wqe_dec_running(struct io_worker *worker)
@@ -348,10 +343,10 @@ static void io_wqe_dec_running(struct io_worker *worker)
if (!(worker->flags & IO_WORKER_F_UP))
return;
- if (atomic_dec_and_test(&acct->nr_running) && io_wqe_run_queue(wqe)) {
+ if (atomic_dec_and_test(&acct->nr_running) && io_acct_run_queue(acct)) {
atomic_inc(&acct->nr_running);
atomic_inc(&wqe->wq->worker_refs);
- io_queue_worker_create(wqe, worker, acct);
+ io_queue_worker_create(worker, acct, create_worker_cb);
}
}
@@ -363,29 +358,10 @@ static void __io_worker_busy(struct io_wqe *wqe, struct io_worker *worker,
struct io_wq_work *work)
__must_hold(wqe->lock)
{
- bool worker_bound, work_bound;
-
- BUILD_BUG_ON((IO_WQ_ACCT_UNBOUND ^ IO_WQ_ACCT_BOUND) != 1);
-
if (worker->flags & IO_WORKER_F_FREE) {
worker->flags &= ~IO_WORKER_F_FREE;
hlist_nulls_del_init_rcu(&worker->nulls_node);
}
-
- /*
- * If worker is moving from bound to unbound (or vice versa), then
- * ensure we update the running accounting.
- */
- worker_bound = (worker->flags & IO_WORKER_F_BOUND) != 0;
- work_bound = (work->flags & IO_WQ_WORK_UNBOUND) == 0;
- if (worker_bound != work_bound) {
- int index = work_bound ? IO_WQ_ACCT_UNBOUND : IO_WQ_ACCT_BOUND;
- io_wqe_dec_running(worker);
- worker->flags ^= IO_WORKER_F_BOUND;
- wqe->acct[index].nr_workers--;
- wqe->acct[index ^ 1].nr_workers++;
- io_wqe_inc_running(worker);
- }
}
/*
@@ -413,7 +389,7 @@ static void io_wait_on_hash(struct io_wqe *wqe, unsigned int hash)
{
struct io_wq *wq = wqe->wq;
- spin_lock(&wq->hash->wait.lock);
+ spin_lock_irq(&wq->hash->wait.lock);
if (list_empty(&wqe->wait.entry)) {
__add_wait_queue(&wq->hash->wait, &wqe->wait);
if (!test_bit(hash, &wq->hash->map)) {
@@ -421,48 +397,26 @@ static void io_wait_on_hash(struct io_wqe *wqe, unsigned int hash)
list_del_init(&wqe->wait.entry);
}
}
- spin_unlock(&wq->hash->wait.lock);
-}
-
-/*
- * We can always run the work if the worker is currently the same type as
- * the work (eg both are bound, or both are unbound). If they are not the
- * same, only allow it if incrementing the worker count would be allowed.
- */
-static bool io_worker_can_run_work(struct io_worker *worker,
- struct io_wq_work *work)
-{
- struct io_wqe_acct *acct;
-
- if (!(worker->flags & IO_WORKER_F_BOUND) !=
- !(work->flags & IO_WQ_WORK_UNBOUND))
- return true;
-
- /* not the same type, check if we'd go over the limit */
- acct = io_work_get_acct(worker->wqe, work);
- return acct->nr_workers < acct->max_workers;
+ spin_unlock_irq(&wq->hash->wait.lock);
}
-static struct io_wq_work *io_get_next_work(struct io_wqe *wqe,
- struct io_worker *worker,
- bool *stalled)
+static struct io_wq_work *io_get_next_work(struct io_wqe_acct *acct,
+ struct io_worker *worker)
__must_hold(wqe->lock)
{
struct io_wq_work_node *node, *prev;
struct io_wq_work *work, *tail;
unsigned int stall_hash = -1U;
+ struct io_wqe *wqe = worker->wqe;
- wq_list_for_each(node, prev, &wqe->work_list) {
+ wq_list_for_each(node, prev, &acct->work_list) {
unsigned int hash;
work = container_of(node, struct io_wq_work, list);
- if (!io_worker_can_run_work(worker, work))
- break;
-
/* not hashed, can run anytime */
if (!io_wq_is_hashed(work)) {
- wq_list_del(&wqe->work_list, node, prev);
+ wq_list_del(&acct->work_list, node, prev);
return work;
}
@@ -473,7 +427,7 @@ static struct io_wq_work *io_get_next_work(struct io_wqe *wqe,
/* hashed, can run if not already running */
if (!test_and_set_bit(hash, &wqe->wq->hash->map)) {
wqe->hash_tail[hash] = NULL;
- wq_list_cut(&wqe->work_list, &tail->list, prev);
+ wq_list_cut(&acct->work_list, &tail->list, prev);
return work;
}
if (stall_hash == -1U)
@@ -483,10 +437,14 @@ static struct io_wq_work *io_get_next_work(struct io_wqe *wqe,
}
if (stall_hash != -1U) {
+ /*
+ * Set this before dropping the lock to avoid racing with new
+ * work being added and clearing the stalled bit.
+ */
+ set_bit(IO_ACCT_STALLED_BIT, &acct->flags);
raw_spin_unlock(&wqe->lock);
io_wait_on_hash(wqe, stall_hash);
raw_spin_lock(&wqe->lock);
- *stalled = true;
}
return NULL;
@@ -520,13 +478,13 @@ static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work);
static void io_worker_handle_work(struct io_worker *worker)
__releases(wqe->lock)
{
+ struct io_wqe_acct *acct = io_wqe_get_acct(worker);
struct io_wqe *wqe = worker->wqe;
struct io_wq *wq = wqe->wq;
bool do_kill = test_bit(IO_WQ_BIT_EXIT, &wq->state);
do {
struct io_wq_work *work;
- bool stalled;
get_next:
/*
* If we got some work, mark us as busy. If we didn't, but
@@ -535,12 +493,9 @@ get_next:
* can't make progress, any work completion or insertion will
* clear the stalled flag.
*/
- stalled = false;
- work = io_get_next_work(wqe, worker, &stalled);
+ work = io_get_next_work(acct, worker);
if (work)
__io_worker_busy(wqe, worker, work);
- else if (stalled)
- wqe->flags |= IO_WQE_FLAG_STALLED;
raw_spin_unlock(&wqe->lock);
if (!work)
@@ -572,10 +527,10 @@ get_next:
if (hash != -1U && !next_hashed) {
clear_bit(hash, &wq->hash->map);
+ clear_bit(IO_ACCT_STALLED_BIT, &acct->flags);
if (wq_has_sleeper(&wq->hash->wait))
wake_up(&wq->hash->wait);
raw_spin_lock(&wqe->lock);
- wqe->flags &= ~IO_WQE_FLAG_STALLED;
/* skip unnecessary unlock-lock wqe->lock */
if (!work)
goto get_next;
@@ -590,8 +545,10 @@ get_next:
static int io_wqe_worker(void *data)
{
struct io_worker *worker = data;
+ struct io_wqe_acct *acct = io_wqe_get_acct(worker);
struct io_wqe *wqe = worker->wqe;
struct io_wq *wq = wqe->wq;
+ bool last_timeout = false;
char buf[TASK_COMM_LEN];
worker->flags |= (IO_WORKER_F_UP | IO_WORKER_F_RUNNING);
@@ -605,10 +562,18 @@ static int io_wqe_worker(void *data)
set_current_state(TASK_INTERRUPTIBLE);
loop:
raw_spin_lock(&wqe->lock);
- if (io_wqe_run_queue(wqe)) {
+ if (io_acct_run_queue(acct)) {
io_worker_handle_work(worker);
goto loop;
}
+ /* timed out, exit unless we're the last worker */
+ if (last_timeout && acct->nr_workers > 1) {
+ acct->nr_workers--;
+ raw_spin_unlock(&wqe->lock);
+ __set_current_state(TASK_RUNNING);
+ break;
+ }
+ last_timeout = false;
__io_worker_idle(wqe, worker);
raw_spin_unlock(&wqe->lock);
if (io_flush_signals())
@@ -619,13 +584,12 @@ loop:
if (!get_signal(&ksig))
continue;
- break;
- }
- if (ret)
+ if (fatal_signal_pending(current) ||
+ signal_group_exit(current->signal))
+ break;
continue;
- /* timed out, exit unless we're the fixed worker */
- if (!(worker->flags & IO_WORKER_F_FIXED))
- break;
+ }
+ last_timeout = !ret;
}
if (test_bit(IO_WQ_BIT_EXIT, &wq->state)) {
@@ -676,51 +640,131 @@ void io_wq_worker_sleeping(struct task_struct *tsk)
raw_spin_unlock(&worker->wqe->lock);
}
-static void create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index, bool first)
+static void io_init_new_worker(struct io_wqe *wqe, struct io_worker *worker,
+ struct task_struct *tsk)
+{
+ tsk->pf_io_worker = worker;
+ worker->task = tsk;
+ set_cpus_allowed_ptr(tsk, wqe->cpu_mask);
+ tsk->flags |= PF_NO_SETAFFINITY;
+
+ raw_spin_lock(&wqe->lock);
+ hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list);
+ list_add_tail_rcu(&worker->all_list, &wqe->all_list);
+ worker->flags |= IO_WORKER_F_FREE;
+ raw_spin_unlock(&wqe->lock);
+ wake_up_new_task(tsk);
+}
+
+static bool io_wq_work_match_all(struct io_wq_work *work, void *data)
+{
+ return true;
+}
+
+static inline bool io_should_retry_thread(long err)
+{
+ switch (err) {
+ case -EAGAIN:
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR:
+ case -ERESTARTNOHAND:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static void create_worker_cont(struct callback_head *cb)
{
- struct io_wqe_acct *acct = &wqe->acct[index];
struct io_worker *worker;
struct task_struct *tsk;
+ struct io_wqe *wqe;
- __set_current_state(TASK_RUNNING);
+ worker = container_of(cb, struct io_worker, create_work);
+ clear_bit_unlock(0, &worker->create_state);
+ wqe = worker->wqe;
+ tsk = create_io_thread(io_wqe_worker, worker, wqe->node);
+ if (!IS_ERR(tsk)) {
+ io_init_new_worker(wqe, worker, tsk);
+ io_worker_release(worker);
+ return;
+ } else if (!io_should_retry_thread(PTR_ERR(tsk))) {
+ struct io_wqe_acct *acct = io_wqe_get_acct(worker);
- worker = kzalloc_node(sizeof(*worker), GFP_KERNEL, wqe->node);
- if (!worker)
- goto fail;
+ atomic_dec(&acct->nr_running);
+ raw_spin_lock(&wqe->lock);
+ acct->nr_workers--;
+ if (!acct->nr_workers) {
+ struct io_cb_cancel_data match = {
+ .fn = io_wq_work_match_all,
+ .cancel_all = true,
+ };
- refcount_set(&worker->ref, 1);
- worker->nulls_node.pprev = NULL;
- worker->wqe = wqe;
- spin_lock_init(&worker->lock);
- init_completion(&worker->ref_done);
+ while (io_acct_cancel_pending_work(wqe, acct, &match))
+ raw_spin_lock(&wqe->lock);
+ }
+ raw_spin_unlock(&wqe->lock);
+ io_worker_ref_put(wqe->wq);
+ kfree(worker);
+ return;
+ }
- tsk = create_io_thread(io_wqe_worker, worker, wqe->node);
- if (IS_ERR(tsk)) {
+ /* re-create attempts grab a new worker ref, drop the existing one */
+ io_worker_release(worker);
+ schedule_work(&worker->work);
+}
+
+static void io_workqueue_create(struct work_struct *work)
+{
+ struct io_worker *worker = container_of(work, struct io_worker, work);
+ struct io_wqe_acct *acct = io_wqe_get_acct(worker);
+
+ if (!io_queue_worker_create(worker, acct, create_worker_cont)) {
+ clear_bit_unlock(0, &worker->create_state);
+ io_worker_release(worker);
kfree(worker);
+ }
+}
+
+static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index)
+{
+ struct io_wqe_acct *acct = &wqe->acct[index];
+ struct io_worker *worker;
+ struct task_struct *tsk;
+
+ __set_current_state(TASK_RUNNING);
+
+ worker = kzalloc_node(sizeof(*worker), GFP_KERNEL, wqe->node);
+ if (!worker) {
fail:
atomic_dec(&acct->nr_running);
raw_spin_lock(&wqe->lock);
acct->nr_workers--;
raw_spin_unlock(&wqe->lock);
io_worker_ref_put(wq);
- return;
+ return false;
}
- tsk->pf_io_worker = worker;
- worker->task = tsk;
- set_cpus_allowed_ptr(tsk, wqe->cpu_mask);
- tsk->flags |= PF_NO_SETAFFINITY;
+ refcount_set(&worker->ref, 1);
+ worker->wqe = wqe;
+ spin_lock_init(&worker->lock);
+ init_completion(&worker->ref_done);
- raw_spin_lock(&wqe->lock);
- hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list);
- list_add_tail_rcu(&worker->all_list, &wqe->all_list);
- worker->flags |= IO_WORKER_F_FREE;
if (index == IO_WQ_ACCT_BOUND)
worker->flags |= IO_WORKER_F_BOUND;
- if (first && (worker->flags & IO_WORKER_F_BOUND))
- worker->flags |= IO_WORKER_F_FIXED;
- raw_spin_unlock(&wqe->lock);
- wake_up_new_task(tsk);
+
+ tsk = create_io_thread(io_wqe_worker, worker, wqe->node);
+ if (!IS_ERR(tsk)) {
+ io_init_new_worker(wqe, worker, tsk);
+ } else if (!io_should_retry_thread(PTR_ERR(tsk))) {
+ kfree(worker);
+ goto fail;
+ } else {
+ INIT_WORK(&worker->work, io_workqueue_create);
+ schedule_work(&worker->work);
+ }
+
+ return true;
}
/*
@@ -755,11 +799,6 @@ static bool io_wq_worker_wake(struct io_worker *worker, void *data)
return false;
}
-static bool io_wq_work_match_all(struct io_wq_work *work, void *data)
-{
- return true;
-}
-
static void io_run_cancel(struct io_wq_work *work, struct io_wqe *wqe)
{
struct io_wq *wq = wqe->wq;
@@ -773,12 +812,13 @@ static void io_run_cancel(struct io_wq_work *work, struct io_wqe *wqe)
static void io_wqe_insert_work(struct io_wqe *wqe, struct io_wq_work *work)
{
+ struct io_wqe_acct *acct = io_work_get_acct(wqe, work);
unsigned int hash;
struct io_wq_work *tail;
if (!io_wq_is_hashed(work)) {
append:
- wq_list_add_tail(&work->list, &wqe->work_list);
+ wq_list_add_tail(&work->list, &acct->work_list);
return;
}
@@ -788,13 +828,19 @@ append:
if (!tail)
goto append;
- wq_list_add_after(&work->list, &tail->list, &wqe->work_list);
+ wq_list_add_after(&work->list, &tail->list, &acct->work_list);
+}
+
+static bool io_wq_work_match_item(struct io_wq_work *work, void *data)
+{
+ return work == data;
}
static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work)
{
struct io_wqe_acct *acct = io_work_get_acct(wqe, work);
- bool do_wake;
+ unsigned work_flags = work->flags;
+ bool do_create;
/*
* If io-wq is exiting for this task, or if the request has explicitly
@@ -808,13 +854,36 @@ static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work)
raw_spin_lock(&wqe->lock);
io_wqe_insert_work(wqe, work);
- wqe->flags &= ~IO_WQE_FLAG_STALLED;
- do_wake = (work->flags & IO_WQ_WORK_CONCURRENT) ||
- !atomic_read(&acct->nr_running);
+ clear_bit(IO_ACCT_STALLED_BIT, &acct->flags);
+
+ rcu_read_lock();
+ do_create = !io_wqe_activate_free_worker(wqe, acct);
+ rcu_read_unlock();
+
raw_spin_unlock(&wqe->lock);
- if (do_wake)
- io_wqe_wake_worker(wqe, acct);
+ if (do_create && ((work_flags & IO_WQ_WORK_CONCURRENT) ||
+ !atomic_read(&acct->nr_running))) {
+ bool did_create;
+
+ did_create = io_wqe_create_worker(wqe, acct);
+ if (likely(did_create))
+ return;
+
+ raw_spin_lock(&wqe->lock);
+ /* fatal condition, failed to create the first worker */
+ if (!acct->nr_workers) {
+ struct io_cb_cancel_data match = {
+ .fn = io_wq_work_match_item,
+ .data = work,
+ .cancel_all = false,
+ };
+
+ if (io_acct_cancel_pending_work(wqe, acct, &match))
+ raw_spin_lock(&wqe->lock);
+ }
+ raw_spin_unlock(&wqe->lock);
+ }
}
void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work)
@@ -859,6 +928,7 @@ static inline void io_wqe_remove_pending(struct io_wqe *wqe,
struct io_wq_work *work,
struct io_wq_work_node *prev)
{
+ struct io_wqe_acct *acct = io_work_get_acct(wqe, work);
unsigned int hash = io_get_work_hash(work);
struct io_wq_work *prev_work = NULL;
@@ -870,18 +940,18 @@ static inline void io_wqe_remove_pending(struct io_wqe *wqe,
else
wqe->hash_tail[hash] = NULL;
}
- wq_list_del(&wqe->work_list, &work->list, prev);
+ wq_list_del(&acct->work_list, &work->list, prev);
}
-static void io_wqe_cancel_pending_work(struct io_wqe *wqe,
- struct io_cb_cancel_data *match)
+static bool io_acct_cancel_pending_work(struct io_wqe *wqe,
+ struct io_wqe_acct *acct,
+ struct io_cb_cancel_data *match)
+ __releases(wqe->lock)
{
struct io_wq_work_node *node, *prev;
struct io_wq_work *work;
-retry:
- raw_spin_lock(&wqe->lock);
- wq_list_for_each(node, prev, &wqe->work_list) {
+ wq_list_for_each(node, prev, &acct->work_list) {
work = container_of(node, struct io_wq_work, list);
if (!match->fn(work, match->data))
continue;
@@ -889,11 +959,27 @@ retry:
raw_spin_unlock(&wqe->lock);
io_run_cancel(work, wqe);
match->nr_pending++;
- if (!match->cancel_all)
- return;
-
/* not safe to continue after unlock */
- goto retry;
+ return true;
+ }
+
+ return false;
+}
+
+static void io_wqe_cancel_pending_work(struct io_wqe *wqe,
+ struct io_cb_cancel_data *match)
+{
+ int i;
+retry:
+ raw_spin_lock(&wqe->lock);
+ for (i = 0; i < IO_WQ_ACCT_NR; i++) {
+ struct io_wqe_acct *acct = io_get_acct(wqe, i == 0);
+
+ if (io_acct_cancel_pending_work(wqe, acct, match)) {
+ if (match->cancel_all)
+ goto retry;
+ return;
+ }
}
raw_spin_unlock(&wqe->lock);
}
@@ -954,18 +1040,24 @@ static int io_wqe_hash_wake(struct wait_queue_entry *wait, unsigned mode,
int sync, void *key)
{
struct io_wqe *wqe = container_of(wait, struct io_wqe, wait);
+ int i;
list_del_init(&wait->entry);
rcu_read_lock();
- io_wqe_activate_free_worker(wqe);
+ for (i = 0; i < IO_WQ_ACCT_NR; i++) {
+ struct io_wqe_acct *acct = &wqe->acct[i];
+
+ if (test_and_clear_bit(IO_ACCT_STALLED_BIT, &acct->flags))
+ io_wqe_activate_free_worker(wqe, acct);
+ }
rcu_read_unlock();
return 1;
}
struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
{
- int ret, node;
+ int ret, node, i;
struct io_wq *wq;
if (WARN_ON_ONCE(!data->free_work || !data->do_work))
@@ -1000,18 +1092,20 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
cpumask_copy(wqe->cpu_mask, cpumask_of_node(node));
wq->wqes[node] = wqe;
wqe->node = alloc_node;
- wqe->acct[IO_WQ_ACCT_BOUND].index = IO_WQ_ACCT_BOUND;
- wqe->acct[IO_WQ_ACCT_UNBOUND].index = IO_WQ_ACCT_UNBOUND;
wqe->acct[IO_WQ_ACCT_BOUND].max_workers = bounded;
- atomic_set(&wqe->acct[IO_WQ_ACCT_BOUND].nr_running, 0);
wqe->acct[IO_WQ_ACCT_UNBOUND].max_workers =
task_rlimit(current, RLIMIT_NPROC);
- atomic_set(&wqe->acct[IO_WQ_ACCT_UNBOUND].nr_running, 0);
- wqe->wait.func = io_wqe_hash_wake;
INIT_LIST_HEAD(&wqe->wait.entry);
+ wqe->wait.func = io_wqe_hash_wake;
+ for (i = 0; i < IO_WQ_ACCT_NR; i++) {
+ struct io_wqe_acct *acct = &wqe->acct[i];
+
+ acct->index = i;
+ atomic_set(&acct->nr_running, 0);
+ INIT_WQ_LIST(&acct->work_list);
+ }
wqe->wq = wq;
raw_spin_lock_init(&wqe->lock);
- INIT_WQ_LIST(&wqe->work_list);
INIT_HLIST_NULLS_HEAD(&wqe->free_list, 0);
INIT_LIST_HEAD(&wqe->all_list);
}
@@ -1038,7 +1132,7 @@ static bool io_task_work_match(struct callback_head *cb, void *data)
{
struct io_worker *worker;
- if (cb->func != create_worker_cb)
+ if (cb->func != create_worker_cb && cb->func != create_worker_cont)
return false;
worker = container_of(cb, struct io_worker, create_work);
return worker->wqe->wq == data;
@@ -1059,9 +1153,14 @@ static void io_wq_exit_workers(struct io_wq *wq)
while ((cb = task_work_cancel_match(wq->task, io_task_work_match, wq)) != NULL) {
struct io_worker *worker;
+ struct io_wqe_acct *acct;
worker = container_of(cb, struct io_worker, create_work);
- atomic_dec(&worker->wqe->acct[worker->create_index].nr_running);
+ acct = io_wqe_get_acct(worker);
+ atomic_dec(&acct->nr_running);
+ raw_spin_lock(&worker->wqe->lock);
+ acct->nr_workers--;
+ raw_spin_unlock(&worker->wqe->lock);
io_worker_ref_put(wq);
clear_bit_unlock(0, &worker->create_state);
io_worker_release(worker);
@@ -1184,6 +1283,10 @@ int io_wq_max_workers(struct io_wq *wq, int *new_count)
{
int i, node, prev = 0;
+ BUILD_BUG_ON((int) IO_WQ_ACCT_BOUND != (int) IO_WQ_BOUND);
+ BUILD_BUG_ON((int) IO_WQ_ACCT_UNBOUND != (int) IO_WQ_UNBOUND);
+ BUILD_BUG_ON((int) IO_WQ_ACCT_NR != 2);
+
for (i = 0; i < 2; i++) {
if (new_count[i] > task_rlimit(current, RLIMIT_NPROC))
new_count[i] = task_rlimit(current, RLIMIT_NPROC);
@@ -1193,7 +1296,7 @@ int io_wq_max_workers(struct io_wq *wq, int *new_count)
for_each_node(node) {
struct io_wqe_acct *acct;
- for (i = 0; i < 2; i++) {
+ for (i = 0; i < IO_WQ_ACCT_NR; i++) {
acct = &wq->wqes[node]->acct[i];
prev = max_t(int, acct->max_workers, prev);
if (new_count[i])