diff options
| -rw-r--r-- | fs/proc/array.c | 33 | ||||
| -rw-r--r-- | fs/proc/base.c | 5 | ||||
| -rw-r--r-- | fs/proc/internal.h | 2 | ||||
| -rw-r--r-- | include/linux/workqueue.h | 1 | ||||
| -rw-r--r-- | kernel/workqueue.c | 139 | ||||
| -rw-r--r-- | kernel/workqueue_internal.h | 3 |
6 files changed, 119 insertions, 64 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c index e6d7f41b6684..004077f1a7bf 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -96,22 +96,29 @@ #include <asm/processor.h> #include "internal.h" -static inline void task_name(struct seq_file *m, struct task_struct *p) +void proc_task_name(struct seq_file *m, struct task_struct *p, bool escape) { char *buf; size_t size; - char tcomm[sizeof(p->comm)]; + char tcomm[64]; int ret; - get_task_comm(tcomm, p); - - seq_puts(m, "Name:\t"); + if (p->flags & PF_WQ_WORKER) + wq_worker_comm(tcomm, sizeof(tcomm), p); + else + __get_task_comm(tcomm, sizeof(tcomm), p); size = seq_get_buf(m, &buf); - ret = string_escape_str(tcomm, buf, size, ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\"); - seq_commit(m, ret < size ? ret : -1); + if (escape) { + ret = string_escape_str(tcomm, buf, size, + ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\"); + if (ret >= size) + ret = -1; + } else { + ret = strscpy(buf, tcomm, size); + } - seq_putc(m, '\n'); + seq_commit(m, ret); } /* @@ -390,7 +397,10 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns, { struct mm_struct *mm = get_task_mm(task); - task_name(m, task); + seq_puts(m, "Name:\t"); + proc_task_name(m, task, true); + seq_putc(m, '\n'); + task_state(m, ns, pid, task); if (mm) { @@ -425,7 +435,6 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns, u64 cutime, cstime, utime, stime; u64 cgtime, gtime; unsigned long rsslim = 0; - char tcomm[sizeof(task->comm)]; unsigned long flags; state = *get_task_state(task); @@ -452,8 +461,6 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns, } } - get_task_comm(tcomm, task); - sigemptyset(&sigign); sigemptyset(&sigcatch); cutime = cstime = utime = stime = 0; @@ -520,7 +527,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns, seq_put_decimal_ull(m, "", pid_nr_ns(pid, ns)); seq_puts(m, " ("); - seq_puts(m, tcomm); + proc_task_name(m, task, false); seq_puts(m, ") "); seq_putc(m, state); seq_put_decimal_ll(m, " ", ppid); diff --git a/fs/proc/base.c b/fs/proc/base.c index 33ed1746927a..af128b374143 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1563,9 +1563,8 @@ static int comm_show(struct seq_file *m, void *v) if (!p) return -ESRCH; - task_lock(p); - seq_printf(m, "%s\n", p->comm); - task_unlock(p); + proc_task_name(m, p, false); + seq_putc(m, '\n'); put_task_struct(p); diff --git a/fs/proc/internal.h b/fs/proc/internal.h index 43c70c9e6b62..93eb1906c28d 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -136,6 +136,8 @@ unsigned name_to_int(const struct qstr *qstr); */ extern const struct file_operations proc_tid_children_operations; +extern void proc_task_name(struct seq_file *m, struct task_struct *p, + bool escape); extern int proc_tid_stat(struct seq_file *, struct pid_namespace *, struct pid *, struct task_struct *); extern int proc_tgid_stat(struct seq_file *, struct pid_namespace *, diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 39a0e215022a..60d673e15632 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -494,6 +494,7 @@ extern unsigned int work_busy(struct work_struct *work); extern __printf(1, 2) void set_worker_desc(const char *fmt, ...); extern void print_worker_info(const char *log_lvl, struct task_struct *task); extern void show_workqueue_state(void); +extern void wq_worker_comm(char *buf, size_t size, struct task_struct *task); /** * queue_work - queue work on a workqueue diff --git a/kernel/workqueue.c b/kernel/workqueue.c index ca7959be8aaa..7ea75529eabb 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -66,7 +66,7 @@ enum { * be executing on any CPU. The pool behaves as an unbound one. * * Note that DISASSOCIATED should be flipped only while holding - * attach_mutex to avoid changing binding state while + * wq_pool_attach_mutex to avoid changing binding state while * worker_attach_to_pool() is in progress. */ POOL_MANAGER_ACTIVE = 1 << 0, /* being managed */ @@ -123,7 +123,7 @@ enum { * cpu or grabbing pool->lock is enough for read access. If * POOL_DISASSOCIATED is set, it's identical to L. * - * A: pool->attach_mutex protected. + * A: wq_pool_attach_mutex protected. * * PL: wq_pool_mutex protected. * @@ -166,7 +166,6 @@ struct worker_pool { /* L: hash of busy workers */ struct worker *manager; /* L: purely informational */ - struct mutex attach_mutex; /* attach/detach exclusion */ struct list_head workers; /* A: attached workers */ struct completion *detach_completion; /* all workers detached */ @@ -297,6 +296,7 @@ static bool wq_numa_enabled; /* unbound NUMA affinity enabled */ static struct workqueue_attrs *wq_update_unbound_numa_attrs_buf; static DEFINE_MUTEX(wq_pool_mutex); /* protects pools and workqueues list */ +static DEFINE_MUTEX(wq_pool_attach_mutex); /* protects worker attach/detach */ static DEFINE_SPINLOCK(wq_mayday_lock); /* protects wq->maydays list */ static DECLARE_WAIT_QUEUE_HEAD(wq_manager_wait); /* wait for manager to go away */ @@ -399,14 +399,14 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq); * @worker: iteration cursor * @pool: worker_pool to iterate workers of * - * This must be called with @pool->attach_mutex. + * This must be called with wq_pool_attach_mutex. * * The if/else clause exists only for the lockdep assertion and can be * ignored. */ #define for_each_pool_worker(worker, pool) \ list_for_each_entry((worker), &(pool)->workers, node) \ - if (({ lockdep_assert_held(&pool->attach_mutex); false; })) { } \ + if (({ lockdep_assert_held(&wq_pool_attach_mutex); false; })) { } \ else /** @@ -1724,7 +1724,7 @@ static struct worker *alloc_worker(int node) static void worker_attach_to_pool(struct worker *worker, struct worker_pool *pool) { - mutex_lock(&pool->attach_mutex); + mutex_lock(&wq_pool_attach_mutex); /* * set_cpus_allowed_ptr() will fail if the cpumask doesn't have any @@ -1733,37 +1733,40 @@ static void worker_attach_to_pool(struct worker *worker, set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask); /* - * The pool->attach_mutex ensures %POOL_DISASSOCIATED remains - * stable across this function. See the comments above the - * flag definition for details. + * The wq_pool_attach_mutex ensures %POOL_DISASSOCIATED remains + * stable across this function. See the comments above the flag + * definition for details. */ if (pool->flags & POOL_DISASSOCIATED) worker->flags |= WORKER_UNBOUND; list_add_tail(&worker->node, &pool->workers); + worker->pool = pool; - mutex_unlock(&pool->attach_mutex); + mutex_unlock(&wq_pool_attach_mutex); } /** * worker_detach_from_pool() - detach a worker from its pool * @worker: worker which is attached to its pool - * @pool: the pool @worker is attached to * * Undo the attaching which had been done in worker_attach_to_pool(). The * caller worker shouldn't access to the pool after detached except it has * other reference to the pool. */ -static void worker_detach_from_pool(struct worker *worker, - struct worker_pool *pool) +static void worker_detach_from_pool(struct worker *worker) { + struct worker_pool *pool = worker->pool; struct completion *detach_completion = NULL; - mutex_lock(&pool->attach_mutex); + mutex_lock(&wq_pool_attach_mutex); + list_del(&worker->node); + worker->pool = NULL; + if (list_empty(&pool->workers)) detach_completion = pool->detach_completion; - mutex_unlock(&pool->attach_mutex); + mutex_unlock(&wq_pool_attach_mutex); /* clear leftover flags without pool->lock after it is detached */ worker->flags &= ~(WORKER_UNBOUND | WORKER_REBOUND); @@ -1799,7 +1802,6 @@ static struct worker *create_worker(struct worker_pool *pool) if (!worker) goto fail; - worker->pool = pool; worker->id = id; if (pool->cpu >= 0) @@ -2086,6 +2088,12 @@ __acquires(&pool->lock) worker->current_pwq = pwq; work_color = get_work_color(work); + /* + * Record wq name for cmdline and debug reporting, may get + * overridden through set_worker_desc(). + */ + strscpy(worker->desc, pwq->wq->name, WORKER_DESC_LEN); + list_del_init(&work->entry); /* @@ -2181,7 +2189,6 @@ __acquires(&pool->lock) worker->current_work = NULL; worker->current_func = NULL; worker->current_pwq = NULL; - worker->desc_valid = false; pwq_dec_nr_in_flight(pwq, work_color); } @@ -2206,6 +2213,16 @@ static void process_scheduled_works(struct worker *worker) } } +static void set_pf_worker(bool val) +{ + mutex_lock(&wq_pool_attach_mutex); + if (val) + current->flags |= PF_WQ_WORKER; + else + current->flags &= ~PF_WQ_WORKER; + mutex_unlock(&wq_pool_attach_mutex); +} + /** * worker_thread - the worker thread function * @__worker: self @@ -2224,7 +2241,7 @@ static int worker_thread(void *__worker) struct worker_pool *pool = worker->pool; /* tell the scheduler that this is a workqueue worker */ - worker->task->flags |= PF_WQ_WORKER; + set_pf_worker(true); woke_up: spin_lock_irq(&pool->lock); @@ -2232,11 +2249,11 @@ woke_up: if (unlikely(worker->flags & WORKER_DIE)) { spin_unlock_irq(&pool->lock); WARN_ON_ONCE(!list_empty(&worker->entry)); - worker->task->flags &= ~PF_WQ_WORKER; + set_pf_worker(false); set_task_comm(worker->task, "kworker/dying"); ida_simple_remove(&pool->worker_ida, worker->id); - worker_detach_from_pool(worker, pool); + worker_detach_from_pool(worker); kfree(worker); return 0; } @@ -2335,7 +2352,7 @@ static int rescuer_thread(void *__rescuer) * Mark rescuer as worker too. As WORKER_PREP is never cleared, it * doesn't participate in concurrency management. */ - rescuer->task->flags |= PF_WQ_WORKER; + set_pf_worker(true); repeat: set_current_state(TASK_IDLE); @@ -2367,7 +2384,6 @@ repeat: worker_attach_to_pool(rescuer, pool); spin_lock_irq(&pool->lock); - rescuer->pool = pool; /* * Slurp in all works issued via this workqueue and @@ -2417,10 +2433,9 @@ repeat: if (need_more_worker(pool)) wake_up_worker(pool); - rescuer->pool = NULL; spin_unlock_irq(&pool->lock); - worker_detach_from_pool(rescuer, pool); + worker_detach_from_pool(rescuer); spin_lock_irq(&wq_mayday_lock); } @@ -2429,7 +2444,7 @@ repeat: if (should_stop) { __set_current_state(TASK_RUNNING); - rescuer->task->flags &= ~PF_WQ_WORKER; + set_pf_worker(false); return 0; } @@ -3271,7 +3286,6 @@ static int init_worker_pool(struct worker_pool *pool) timer_setup(&pool->mayday_timer, pool_mayday_timeout, 0); - mutex_init(&pool->attach_mutex); INIT_LIST_HEAD(&pool->workers); ida_init(&pool->worker_ida); @@ -3354,10 +3368,10 @@ static void put_unbound_pool(struct worker_pool *pool) WARN_ON(pool->nr_workers || pool->nr_idle); spin_unlock_irq(&pool->lock); - mutex_lock(&pool->attach_mutex); + mutex_lock(&wq_pool_attach_mutex); if (!list_empty(&pool->workers)) pool->detach_completion = &detach_completion; - mutex_unlock(&pool->attach_mutex); + mutex_unlock(&wq_pool_attach_mutex); if (pool->detach_completion) wait_for_completion(pool->detach_completion); @@ -4347,7 +4361,6 @@ void set_worker_desc(const char *fmt, ...) va_start(args, fmt); vsnprintf(worker->desc, sizeof(worker->desc), fmt, args); va_end(args); - worker->desc_valid = true; } } @@ -4371,7 +4384,6 @@ void print_worker_info(const char *log_lvl, struct task_struct *task) char desc[WORKER_DESC_LEN] = { }; struct pool_workqueue *pwq = NULL; struct workqueue_struct *wq = NULL; - bool desc_valid = false; struct worker *worker; if (!(task->flags & PF_WQ_WORKER)) @@ -4384,22 +4396,18 @@ void print_worker_info(const char *log_lvl, struct task_struct *task) worker = kthread_probe_data(task); /* - * Carefully copy the associated workqueue's workfn and name. Keep - * the original last '\0' in case the original contains garbage. + * Carefully copy the associated workqueue's workfn, name and desc. + * Keep the original last '\0' in case the original is garbage. */ probe_kernel_read(&fn, &worker->current_func, sizeof(fn)); probe_kernel_read(&pwq, &worker->current_pwq, sizeof(pwq)); probe_kernel_read(&wq, &pwq->wq, sizeof(wq)); probe_kernel_read(name, wq->name, sizeof(name) - 1); - - /* copy worker description */ - probe_kernel_read(&desc_valid, &worker->desc_valid, sizeof(desc_valid)); - if (desc_valid) - probe_kernel_read(desc, worker->desc, sizeof(desc) - 1); + probe_kernel_read(desc, worker->desc, sizeof(desc) - 1); if (fn || name[0] || desc[0]) { printk("%sWorkqueue: %s %pf", log_lvl, name, fn); - if (desc[0]) + if (strcmp(name, desc)) pr_cont(" (%s)", desc); pr_cont("\n"); } @@ -4579,6 +4587,47 @@ void show_workqueue_state(void) rcu_read_unlock_sched(); } +/* used to show worker information through /proc/PID/{comm,stat,status} */ +void wq_worker_comm(char *buf, size_t size, struct task_struct *task) +{ + int off; + + /* always show the actual comm */ + off = strscpy(buf, task->comm, size); + if (off < 0) + return; + + /* stabilize PF_WQ_WORKER and worker pool association */ + mutex_lock(&wq_pool_attach_mutex); + + if (task->flags & PF_WQ_WORKER) { + struct worker *worker = kthread_data(task); + struct worker_pool *pool = worker->pool; + + if (pool) { + spin_lock_irq(&pool->lock); + /* + * ->desc tracks information (wq name or + * set_worker_desc()) for the latest execution. If + * current, prepend '+', otherwise '-'. + */ + if (worker->desc[0] != '\0') { + if (worker->current_work) + scnprintf(buf + off, size - off, "+%s", + worker->desc); + else + scnprintf(buf + off, size - off, "-%s", + worker->desc); + } + spin_unlock_irq(&pool->lock); + } + } + + mutex_unlock(&wq_pool_attach_mutex); +} + +#ifdef CONFIG_SMP + /* * CPU hotplug. * @@ -4600,7 +4649,7 @@ static void unbind_workers(int cpu) struct worker *worker; for_each_cpu_worker_pool(pool, cpu) { - mutex_lock(&pool->attach_mutex); + mutex_lock(&wq_pool_attach_mutex); spin_lock_irq(&pool->lock); /* @@ -4616,7 +4665,7 @@ static void unbind_workers(int cpu) pool->flags |= POOL_DISASSOCIATED; spin_unlock_irq(&pool->lock); - mutex_unlock(&pool->attach_mutex); + mutex_unlock(&wq_pool_attach_mutex); /* * Call schedule() so that we cross rq->lock and thus can @@ -4657,7 +4706,7 @@ static void rebind_workers(struct worker_pool *pool) { struct worker *worker; - lockdep_assert_held(&pool->attach_mutex); + lockdep_assert_held(&wq_pool_attach_mutex); /* * Restore CPU affinity of all workers. As all idle workers should @@ -4727,7 +4776,7 @@ static void restore_unbound_workers_cpumask(struct worker_pool *pool, int cpu) static cpumask_t cpumask; struct worker *worker; - lockdep_assert_held(&pool->attach_mutex); + lockdep_assert_held(&wq_pool_attach_mutex); /* is @cpu allowed for @pool? */ if (!cpumask_test_cpu(cpu, pool->attrs->cpumask)) @@ -4762,14 +4811,14 @@ int workqueue_online_cpu(unsigned int cpu) mutex_lock(&wq_pool_mutex); for_each_pool(pool, pi) { - mutex_lock(&pool->attach_mutex); + mutex_lock(&wq_pool_attach_mutex); if (pool->cpu == cpu) rebind_workers(pool); else if (pool->cpu < 0) restore_unbound_workers_cpumask(pool, cpu); - mutex_unlock(&pool->attach_mutex); + mutex_unlock(&wq_pool_attach_mutex); } /* update NUMA affinity of unbound workqueues */ @@ -4799,8 +4848,6 @@ int workqueue_offline_cpu(unsigned int cpu) return 0; } -#ifdef CONFIG_SMP - struct work_for_cpu { struct work_struct work; long (*fn)(void *); diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h index d390d1be3748..66fbb5a9e633 100644 --- a/kernel/workqueue_internal.h +++ b/kernel/workqueue_internal.h @@ -31,13 +31,12 @@ struct worker { struct work_struct *current_work; /* L: work being processed */ work_func_t current_func; /* L: current_work's fn */ struct pool_workqueue *current_pwq; /* L: current_work's pwq */ - bool desc_valid; /* ->desc is valid */ struct list_head scheduled; /* L: scheduled works */ /* 64 bytes boundary on 64bit, 32 on 32bit */ struct task_struct *task; /* I: worker task */ - struct worker_pool *pool; /* I: the associated pool */ + struct worker_pool *pool; /* A: the associated pool */ /* L: for rescuers */ struct list_head node; /* A: anchored at pool->workers */ /* A: runs through worker->node */ |