diff options
Diffstat (limited to 'drivers/android/binder.c')
| -rw-r--r-- | drivers/android/binder.c | 255 |
1 files changed, 181 insertions, 74 deletions
diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 56b380292cc5..55a44c0b3b20 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -28,10 +28,10 @@ * binder_node_lock() and binder_node_unlock() are * used to acq/rel * 3) proc->inner_lock : protects the thread and node lists - * (proc->threads, proc->nodes) and all todo lists associated - * with the binder_proc (proc->todo, thread->todo, - * proc->delivered_death and node->async_todo), as well as - * thread->transaction_stack + * (proc->threads, proc->waiting_threads, proc->nodes) + * and all todo lists associated with the binder_proc + * (proc->todo, thread->todo, proc->delivered_death and + * node->async_todo), as well as thread->transaction_stack * binder_inner_proc_lock() and binder_inner_proc_unlock() * are used to acq/rel * @@ -475,6 +475,8 @@ enum binder_deferred_state { * (protected by @outer_lock) * @refs_by_node: rbtree of refs ordered by ref->node * (protected by @outer_lock) + * @waiting_threads: threads currently waiting for proc work + * (protected by @inner_lock) * @pid PID of group_leader of process * (invariant after initialized) * @tsk task_struct for group_leader of process @@ -504,8 +506,6 @@ enum binder_deferred_state { * (protected by @inner_lock) * @requested_threads_started: number binder threads started * (protected by @inner_lock) - * @ready_threads: number of threads waiting for proc work - * (protected by @inner_lock) * @tmp_ref: temporary reference to indicate proc is in use * (protected by @inner_lock) * @default_priority: default scheduler priority @@ -526,6 +526,7 @@ struct binder_proc { struct rb_root nodes; struct rb_root refs_by_desc; struct rb_root refs_by_node; + struct list_head waiting_threads; int pid; struct task_struct *tsk; struct files_struct *files; @@ -540,7 +541,6 @@ struct binder_proc { int max_threads; int requested_threads; int requested_threads_started; - int ready_threads; int tmp_ref; long default_priority; struct dentry *debugfs_entry; @@ -556,6 +556,7 @@ enum { BINDER_LOOPER_STATE_EXITED = 0x04, BINDER_LOOPER_STATE_INVALID = 0x08, BINDER_LOOPER_STATE_WAITING = 0x10, + BINDER_LOOPER_STATE_POLL = 0x20, }; /** @@ -564,6 +565,8 @@ enum { * (invariant after initialization) * @rb_node: element for proc->threads rbtree * (protected by @proc->inner_lock) + * @waiting_thread_node: element for @proc->waiting_threads list + * (protected by @proc->inner_lock) * @pid: PID for this thread * (invariant after initialization) * @looper: bitmap of looping state @@ -593,6 +596,7 @@ enum { struct binder_thread { struct binder_proc *proc; struct rb_node rb_node; + struct list_head waiting_thread_node; int pid; int looper; /* only modified by this thread */ bool looper_need_return; /* can be written by other thread */ @@ -920,6 +924,86 @@ static long task_close_fd(struct binder_proc *proc, unsigned int fd) return retval; } +static bool binder_has_work_ilocked(struct binder_thread *thread, + bool do_proc_work) +{ + return !binder_worklist_empty_ilocked(&thread->todo) || + thread->looper_need_return || + (do_proc_work && + !binder_worklist_empty_ilocked(&thread->proc->todo)); +} + +static bool binder_has_work(struct binder_thread *thread, bool do_proc_work) +{ + bool has_work; + + binder_inner_proc_lock(thread->proc); + has_work = binder_has_work_ilocked(thread, do_proc_work); + binder_inner_proc_unlock(thread->proc); + + return has_work; +} + +static bool binder_available_for_proc_work_ilocked(struct binder_thread *thread) +{ + return !thread->transaction_stack && + binder_worklist_empty_ilocked(&thread->todo) && + (thread->looper & (BINDER_LOOPER_STATE_ENTERED | + BINDER_LOOPER_STATE_REGISTERED)); +} + +static void binder_wakeup_poll_threads_ilocked(struct binder_proc *proc, + bool sync) +{ + struct rb_node *n; + struct binder_thread *thread; + + for (n = rb_first(&proc->threads); n != NULL; n = rb_next(n)) { + thread = rb_entry(n, struct binder_thread, rb_node); + if (thread->looper & BINDER_LOOPER_STATE_POLL && + binder_available_for_proc_work_ilocked(thread)) { + if (sync) + wake_up_interruptible_sync(&thread->wait); + else + wake_up_interruptible(&thread->wait); + } + } +} + +static void binder_wakeup_proc_ilocked(struct binder_proc *proc, bool sync) +{ + struct binder_thread *thread; + + BUG_ON(!spin_is_locked(&proc->inner_lock)); + thread = list_first_entry_or_null(&proc->waiting_threads, + struct binder_thread, + waiting_thread_node); + + if (thread) { + list_del_init(&thread->waiting_thread_node); + if (sync) + wake_up_interruptible_sync(&thread->wait); + else + wake_up_interruptible(&thread->wait); + return; + } + + /* Didn't find a thread waiting for proc work; this can happen + * in two scenarios: + * 1. All threads are busy handling transactions + * In that case, one of those threads should call back into + * the kernel driver soon and pick up this work. + * 2. Threads are using the (e)poll interface, in which case + * they may be blocked on the waitqueue without having been + * added to waiting_threads. For this case, we just iterate + * over all threads not handling transaction work, and + * wake them all up. We wake all because we don't know whether + * a thread that called into (e)poll is handling non-binder + * work currently. + */ + binder_wakeup_poll_threads_ilocked(proc, sync); +} + static void binder_set_nice(long nice) { long min_nice; @@ -1138,7 +1222,7 @@ static bool binder_dec_node_nilocked(struct binder_node *node, if (proc && (node->has_strong_ref || node->has_weak_ref)) { if (list_empty(&node->work.entry)) { binder_enqueue_work_ilocked(&node->work, &proc->todo); - wake_up_interruptible(&node->proc->wait); + binder_wakeup_proc_ilocked(proc, false); } } else { if (hlist_empty(&node->refs) && !node->local_strong_refs && @@ -2399,7 +2483,6 @@ static void binder_transaction(struct binder_proc *proc, struct binder_thread *target_thread = NULL; struct binder_node *target_node = NULL; struct list_head *target_list; - wait_queue_head_t *target_wait; struct binder_transaction *in_reply_to = NULL; struct binder_transaction_log_entry *e; uint32_t return_error = 0; @@ -2409,6 +2492,7 @@ static void binder_transaction(struct binder_proc *proc, binder_size_t last_fixup_min_off = 0; struct binder_context *context = proc->context; int t_debug_id = atomic_inc_return(&binder_last_id); + bool wakeup_for_proc_work = false; e = binder_transaction_log_add(&binder_transaction_log); e->debug_id = t_debug_id; @@ -2572,10 +2656,9 @@ static void binder_transaction(struct binder_proc *proc, if (target_thread) { e->to_thread = target_thread->pid; target_list = &target_thread->todo; - target_wait = &target_thread->wait; } else { target_list = &target_proc->todo; - target_wait = &target_proc->wait; + wakeup_for_proc_work = true; } e->to_proc = target_proc->pid; @@ -2882,7 +2965,7 @@ static void binder_transaction(struct binder_proc *proc, binder_node_lock(target_node); if (target_node->has_async_transaction) { target_list = &target_node->async_todo; - target_wait = NULL; + wakeup_for_proc_work = false; } else target_node->has_async_transaction = 1; /* @@ -2901,11 +2984,13 @@ static void binder_transaction(struct binder_proc *proc, binder_inner_proc_unlock(target_proc); binder_node_unlock(target_node); } - if (target_wait) { - if (reply || !(tr->flags & TF_ONE_WAY)) - wake_up_interruptible_sync(target_wait); - else - wake_up_interruptible(target_wait); + if (target_thread) { + wake_up_interruptible_sync(&target_thread->wait); + } else if (wakeup_for_proc_work) { + binder_inner_proc_lock(target_proc); + binder_wakeup_proc_ilocked(target_proc, + !(tr->flags & TF_ONE_WAY)); + binder_inner_proc_unlock(target_proc); } if (target_thread) binder_thread_dec_tmpref(target_thread); @@ -3345,12 +3430,14 @@ static int binder_thread_write(struct binder_proc *proc, &ref->death->work, &thread->todo); else { - binder_enqueue_work( - proc, + binder_inner_proc_lock(proc); + binder_enqueue_work_ilocked( &ref->death->work, &proc->todo); - wake_up_interruptible( - &proc->wait); + binder_wakeup_proc_ilocked( + proc, + false); + binder_inner_proc_unlock(proc); } } } else { @@ -3385,8 +3472,9 @@ static int binder_thread_write(struct binder_proc *proc, binder_enqueue_work_ilocked( &death->work, &proc->todo); - wake_up_interruptible( - &proc->wait); + binder_wakeup_proc_ilocked( + proc, + false); } } else { BUG_ON(death->work.type != BINDER_WORK_DEAD_BINDER); @@ -3441,7 +3529,8 @@ static int binder_thread_write(struct binder_proc *proc, binder_enqueue_work_ilocked( &death->work, &proc->todo); - wake_up_interruptible(&proc->wait); + binder_wakeup_proc_ilocked( + proc, false); } } binder_inner_proc_unlock(proc); @@ -3468,13 +3557,6 @@ static void binder_stat_br(struct binder_proc *proc, } } -static int binder_has_proc_work(struct binder_proc *proc, - struct binder_thread *thread) -{ - return !binder_worklist_empty(proc, &proc->todo) || - thread->looper_need_return; -} - static int binder_has_thread_work(struct binder_thread *thread) { return !binder_worklist_empty(thread->proc, &thread->todo) || @@ -3512,6 +3594,38 @@ static int binder_put_node_cmd(struct binder_proc *proc, return 0; } +static int binder_wait_for_work(struct binder_thread *thread, + bool do_proc_work) +{ + DEFINE_WAIT(wait); + struct binder_proc *proc = thread->proc; + int ret = 0; + + freezer_do_not_count(); + binder_inner_proc_lock(proc); + for (;;) { + prepare_to_wait(&thread->wait, &wait, TASK_INTERRUPTIBLE); + if (binder_has_work_ilocked(thread, do_proc_work)) + break; + if (do_proc_work) + list_add(&thread->waiting_thread_node, + &proc->waiting_threads); + binder_inner_proc_unlock(proc); + schedule(); + binder_inner_proc_lock(proc); + list_del_init(&thread->waiting_thread_node); + if (signal_pending(current)) { + ret = -ERESTARTSYS; + break; + } + } + finish_wait(&thread->wait, &wait); + binder_inner_proc_unlock(proc); + freezer_count(); + + return ret; +} + static int binder_thread_read(struct binder_proc *proc, struct binder_thread *thread, binder_uintptr_t binder_buffer, size_t size, @@ -3532,10 +3646,7 @@ static int binder_thread_read(struct binder_proc *proc, retry: binder_inner_proc_lock(proc); - wait_for_proc_work = thread->transaction_stack == NULL && - binder_worklist_empty_ilocked(&thread->todo); - if (wait_for_proc_work) - proc->ready_threads++; + wait_for_proc_work = binder_available_for_proc_work_ilocked(thread); binder_inner_proc_unlock(proc); thread->looper |= BINDER_LOOPER_STATE_WAITING; @@ -3552,23 +3663,15 @@ retry: binder_stop_on_user_error < 2); } binder_set_nice(proc->default_priority); - if (non_block) { - if (!binder_has_proc_work(proc, thread)) - ret = -EAGAIN; - } else - ret = wait_event_freezable_exclusive(proc->wait, binder_has_proc_work(proc, thread)); + } + + if (non_block) { + if (!binder_has_work(thread, wait_for_proc_work)) + ret = -EAGAIN; } else { - if (non_block) { - if (!binder_has_thread_work(thread)) - ret = -EAGAIN; - } else - ret = wait_event_freezable(thread->wait, binder_has_thread_work(thread)); + ret = binder_wait_for_work(thread, wait_for_proc_work); } - binder_inner_proc_lock(proc); - if (wait_for_proc_work) - proc->ready_threads--; - binder_inner_proc_unlock(proc); thread->looper &= ~BINDER_LOOPER_STATE_WAITING; if (ret) @@ -3854,7 +3957,8 @@ done: *consumed = ptr - buffer; binder_inner_proc_lock(proc); - if (proc->requested_threads + proc->ready_threads == 0 && + if (proc->requested_threads == 0 && + list_empty(&thread->proc->waiting_threads) && proc->requested_threads_started < proc->max_threads && (thread->looper & (BINDER_LOOPER_STATE_REGISTERED | BINDER_LOOPER_STATE_ENTERED)) /* the user-space code fails to */ @@ -3965,7 +4069,7 @@ static struct binder_thread *binder_get_thread_ilocked( thread->return_error.cmd = BR_OK; thread->reply_error.work.type = BINDER_WORK_RETURN_ERROR; thread->reply_error.cmd = BR_OK; - + INIT_LIST_HEAD(&new_thread->waiting_thread_node); return thread; } @@ -4078,28 +4182,24 @@ static unsigned int binder_poll(struct file *filp, { struct binder_proc *proc = filp->private_data; struct binder_thread *thread = NULL; - int wait_for_proc_work; + bool wait_for_proc_work; thread = binder_get_thread(proc); binder_inner_proc_lock(thread->proc); - wait_for_proc_work = thread->transaction_stack == NULL && - binder_worklist_empty_ilocked(&thread->todo); + thread->looper |= BINDER_LOOPER_STATE_POLL; + wait_for_proc_work = binder_available_for_proc_work_ilocked(thread); + binder_inner_proc_unlock(thread->proc); - if (wait_for_proc_work) { - if (binder_has_proc_work(proc, thread)) - return POLLIN; - poll_wait(filp, &proc->wait, wait); - if (binder_has_proc_work(proc, thread)) - return POLLIN; - } else { - if (binder_has_thread_work(thread)) - return POLLIN; - poll_wait(filp, &thread->wait, wait); - if (binder_has_thread_work(thread)) - return POLLIN; - } + if (binder_has_work(thread, wait_for_proc_work)) + return POLLIN; + + poll_wait(filp, &thread->wait, wait); + + if (binder_has_thread_work(thread)) + return POLLIN; + return 0; } @@ -4146,8 +4246,10 @@ static int binder_ioctl_write_read(struct file *filp, &bwr.read_consumed, filp->f_flags & O_NONBLOCK); trace_binder_read_done(ret); - if (!binder_worklist_empty(proc, &proc->todo)) - wake_up_interruptible(&proc->wait); + binder_inner_proc_lock(proc); + if (!binder_worklist_empty_ilocked(&proc->todo)) + binder_wakeup_proc_ilocked(proc, false); + binder_inner_proc_unlock(proc); if (ret < 0) { if (copy_to_user(ubuf, &bwr, sizeof(bwr))) ret = -EFAULT; @@ -4389,7 +4491,6 @@ static int binder_open(struct inode *nodp, struct file *filp) get_task_struct(current->group_leader); proc->tsk = current->group_leader; INIT_LIST_HEAD(&proc->todo); - init_waitqueue_head(&proc->wait); proc->default_priority = task_nice(current); binder_dev = container_of(filp->private_data, struct binder_device, miscdev); @@ -4399,6 +4500,7 @@ static int binder_open(struct inode *nodp, struct file *filp) binder_stats_created(BINDER_STAT_PROC); proc->pid = current->group_leader->pid; INIT_LIST_HEAD(&proc->delivered_death); + INIT_LIST_HEAD(&proc->waiting_threads); filp->private_data = proc; mutex_lock(&binder_procs_lock); @@ -4450,7 +4552,6 @@ static void binder_deferred_flush(struct binder_proc *proc) } } binder_inner_proc_unlock(proc); - wake_up_interruptible_all(&proc->wait); binder_debug(BINDER_DEBUG_OPEN_CLOSE, "binder_flush: %d woke %d threads\n", proc->pid, @@ -4519,7 +4620,7 @@ static int binder_node_release(struct binder_node *node, int refs) ref->death->work.type = BINDER_WORK_DEAD_BINDER; binder_enqueue_work_ilocked(&ref->death->work, &ref->proc->todo); - wake_up_interruptible(&ref->proc->wait); + binder_wakeup_proc_ilocked(ref->proc, false); binder_inner_proc_unlock(ref->proc); } @@ -5007,23 +5108,29 @@ static void print_binder_proc_stats(struct seq_file *m, struct binder_proc *proc) { struct binder_work *w; + struct binder_thread *thread; struct rb_node *n; - int count, strong, weak; + int count, strong, weak, ready_threads; size_t free_async_space = binder_alloc_get_free_async_space(&proc->alloc); seq_printf(m, "proc %d\n", proc->pid); seq_printf(m, "context %s\n", proc->context->name); count = 0; + ready_threads = 0; binder_inner_proc_lock(proc); for (n = rb_first(&proc->threads); n != NULL; n = rb_next(n)) count++; + + list_for_each_entry(thread, &proc->waiting_threads, waiting_thread_node) + ready_threads++; + seq_printf(m, " threads: %d\n", count); seq_printf(m, " requested threads: %d+%d/%d\n" " ready threads %d\n" " free async space %zd\n", proc->requested_threads, proc->requested_threads_started, proc->max_threads, - proc->ready_threads, + ready_threads, free_async_space); count = 0; for (n = rb_first(&proc->nodes); n != NULL; n = rb_next(n)) |