diff options
| -rw-r--r-- | include/linux/relay.h | 3 | ||||
| -rw-r--r-- | kernel/relay.c | 35 |
2 files changed, 18 insertions, 20 deletions
diff --git a/include/linux/relay.h b/include/linux/relay.h index 759a0f9..6cd8c44 100644 --- a/include/linux/relay.h +++ b/include/linux/relay.h @@ -12,6 +12,7 @@ #include <linux/types.h> #include <linux/sched.h> +#include <linux/timer.h> #include <linux/wait.h> #include <linux/list.h> #include <linux/fs.h> @@ -38,7 +39,7 @@ struct rchan_buf size_t subbufs_consumed; /* count of sub-buffers consumed */ struct rchan *chan; /* associated channel */ wait_queue_head_t read_wait; /* reader wait queue */ - struct delayed_work wake_readers; /* reader wake-up work struct */ + struct timer_list timer; /* reader wake-up timer */ struct dentry *dentry; /* channel file dentry */ struct kref kref; /* channel buffer refcount */ struct page **page_array; /* array of current buffer pages */ diff --git a/kernel/relay.c b/kernel/relay.c index 577f251..e804589 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -310,16 +310,13 @@ static struct rchan_callbacks default_channel_callbacks = { /** * wakeup_readers - wake up readers waiting on a channel - * @work: work struct that contains the the channel buffer + * @data: contains the the channel buffer * - * This is the work function used to defer reader waking. The - * reason waking is deferred is that calling directly from write - * causes problems if you're writing from say the scheduler. + * This is the timer function used to defer reader waking. */ -static void wakeup_readers(struct work_struct *work) +static void wakeup_readers(unsigned long data) { - struct rchan_buf *buf = - container_of(work, struct rchan_buf, wake_readers.work); + struct rchan_buf *buf = (struct rchan_buf *)data; wake_up_interruptible(&buf->read_wait); } @@ -337,11 +334,9 @@ static void __relay_reset(struct rchan_buf *buf, unsigned int init) if (init) { init_waitqueue_head(&buf->read_wait); kref_init(&buf->kref); - INIT_DELAYED_WORK(&buf->wake_readers, NULL); - } else { - cancel_delayed_work(&buf->wake_readers); - flush_scheduled_work(); - } + setup_timer(&buf->timer, wakeup_readers, (unsigned long)buf); + } else + del_timer_sync(&buf->timer); buf->subbufs_produced = 0; buf->subbufs_consumed = 0; @@ -447,8 +442,7 @@ end: static void relay_close_buf(struct rchan_buf *buf) { buf->finalized = 1; - cancel_delayed_work(&buf->wake_readers); - flush_scheduled_work(); + del_timer_sync(&buf->timer); kref_put(&buf->kref, relay_remove_buf); } @@ -608,11 +602,14 @@ size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length) buf->dentry->d_inode->i_size += buf->chan->subbuf_size - buf->padding[old_subbuf]; smp_mb(); - if (waitqueue_active(&buf->read_wait)) { - PREPARE_DELAYED_WORK(&buf->wake_readers, - wakeup_readers); - schedule_delayed_work(&buf->wake_readers, 1); - } + if (waitqueue_active(&buf->read_wait)) + /* + * Calling wake_up_interruptible() from here + * will deadlock if we happen to be logging + * from the scheduler (trying to re-grab + * rq->lock), so defer it. + */ + __mod_timer(&buf->timer, jiffies + 1); } old = buf->data; |
