// SPDX-License-Identifier: GPL-2.0
/*
* Basic worker thread pool for io_uring
*
* Copyright (C) 2019 Jens Axboe
*
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/sched/signal.h>
#include <linux/percpu.h>
#include <linux/slab.h>
#include <linux/rculist_nulls.h>
#include <linux/cpu.h>
#include <linux/cpuset.h>
#include <linux/task_work.h>
#include <linux/audit.h>
#include <linux/mmu_context.h>
#include <uapi/linux/io_uring.h>
#include "io-wq.h"
#include "slist.h"
#include "io_uring.h"
#define WORKER_IDLE_TIMEOUT (5 * HZ)
#define WORKER_INIT_LIMIT 3
enum {
IO_WORKER_F_UP = 0, /* up and active */
IO_WORKER_F_RUNNING = 1, /* account as running */
IO_WORKER_F_FREE = 2, /* worker on free list */
IO_WORKER_F_BOUND = 3, /* is doing bounded work */
};
enum {
IO_WQ_BIT_EXIT = 0, /* wq exiting */
};
enum {
IO_ACCT_STALLED_BIT = 0, /* stalled on hash */
};
/*
* One for each thread in a wq pool
*/
struct io_worker {
refcount_t ref;
int create_index;
unsigned long flags;
struct hlist_nulls_node nulls_node;
struct list_head all_list;
struct task_struct *task;
struct io_wq *wq;
struct io_wq_work *cur_work;
raw_spinlock_t lock;
struct completion ref_done;
unsigned long create_state;
struct callback_head create_work;
int init_retries;
union {
struct rcu_head rcu;
struct work_struct work;
};
};
#if BITS_PER_LONG == 64
#define IO_WQ_HASH_ORDER 6
#else
#define IO_WQ_HASH_ORDER 5
#endif
#define IO_WQ_NR_HASH_BUCKETS (1u << IO_WQ_HASH_ORDER)
struct io_wq_acct {
unsigned nr_workers;
unsigned max_workers;
int index;
atomic_t nr_running;
raw_spinlock_t lock;
struct io_wq_work_list work_list;
unsigned long flags;
};
enum {
IO_WQ_ACCT_BOUND,
IO_WQ_ACCT_UNBOUND,
IO_WQ_ACCT_NR,
};
/*
* Per io_wq state
*/
struct io_wq {
unsigned long state;
free_work_fn *free_work;
io_wq_work_fn *do_work;
struct io_wq_hash *hash;
atomic_t worker_refs;
struct completion worker_done;
struct hlist_node cpuhp_node;
struct task_struct *task;
struct io_wq_acct acct[IO_WQ_ACCT_NR];
/* lock protects access to elements below */
raw_spinlock_t lock;
struct hlist_nulls_head free_list;
struct list_head all_list;
struct wait_queue_entry wait;
struct 