[ltt-dev] [PATCH] ltt-relay: remove work_struct

[Mathieu Desnoyers]

* Lai Jiangshan (laijs at cn.fujitsu.com) wrote:
> 
> Impact: cleanup
> 
> work_struct is not need.
> 

Yes, that looks good. Thanks !

There are also no bad effects on the -rt tree I can think of.

Mathieu

> Signed-off-by: Lai Jiangshan <laijs at cn.fujitsu.com>
> ---
> --- linux-2.6.27.7-lttng-0.61.orig/ltt/ltt-relay.c	2008-12-03 16:25:24.000000000 +0800
> +++ linux-2.6.27.7-lttng-0.61/ltt/ltt-relay.c	2008-12-12 13:04:16.000000000 +0800
> @@ -87,7 +87,6 @@ struct ltt_channel_buf_struct {
>  					 * Wait queue for blocking user space
>  					 * writers
>  					 */
> -	struct work_struct wake_writers;/* Writers wake-up work struct */
>  	atomic_t wakeup_readers;	/* Boolean : wakeup readers waiting ? */
>  } ____cacheline_aligned;
>  
> @@ -241,6 +240,19 @@ static int ltt_remove_buf_file_callback(
>  }
>  
>  /*
> + * Wake writers :
> + *
> + * This must be done after the trace is removed from the RCU list so that there
> + * are no stalled writers.
> + */
> +static void ltt_relay_wake_writers(struct ltt_channel_buf_struct *ltt_buf)
> +{
> +
> +	if (waitqueue_active(&ltt_buf->write_wait))
> +		wake_up_interruptible(&ltt_buf->write_wait);
> +}
> +
> +/*
>   * This function should not be called from NMI interrupt context
>   */
>  static notrace void ltt_buf_unfull(struct rchan_buf *buf,
> @@ -252,8 +264,7 @@ static notrace void ltt_buf_unfull(struc
>  	struct ltt_channel_buf_struct *ltt_buf =
>  		percpu_ptr(ltt_channel->buf, buf->cpu);
>  
> -	if (waitqueue_active(&ltt_buf->write_wait))
> -		schedule_work(&ltt_buf->wake_writers);
> +	ltt_relay_wake_writers(ltt_buf);
>  }
>  
>  /**
> @@ -662,14 +673,6 @@ static void ltt_relay_release_channel(st
>  	kfree(ltt_chan);
>  }
>  
> -static void ltt_wakeup_writers(struct work_struct *work)
> -{
> -	struct ltt_channel_buf_struct *ltt_buf =
> -		container_of(work, struct ltt_channel_buf_struct, wake_writers);
> -
> -	wake_up_interruptible(&ltt_buf->write_wait);
> -}
> -
>  /*
>   * Create ltt buffer.
>   */
> @@ -696,7 +699,6 @@ static int ltt_relay_create_buffer(struc
>  		local_set(&ltt_buf->commit_count[j], 0);
>  	init_waitqueue_head(&ltt_buf->write_wait);
>  	atomic_set(&ltt_buf->wakeup_readers, 0);
> -	INIT_WORK(&ltt_buf->wake_writers, ltt_wakeup_writers);
>  	spin_lock_init(&ltt_buf->full_lock);
>  
>  	ltt_buffer_begin_callback(buf, trace->start_tsc, 0);
> @@ -856,19 +858,6 @@ static void ltt_relay_async_wakeup_chan(
>  	}
>  }
>  
> -/*
> - * Wake writers :
> - *
> - * This must be done after the trace is removed from the RCU list so that there
> - * are no stalled writers.
> - */
> -static void ltt_relay_wake_writers(struct ltt_channel_buf_struct *ltt_buf)
> -{
> -
> -	if (waitqueue_active(&ltt_buf->write_wait))
> -		schedule_work(&ltt_buf->wake_writers);
> -}
> -
>  static void ltt_relay_finish_buffer(struct ltt_channel_struct *ltt_channel,
>  		unsigned int cpu)
>  {
> --- linux-2.6.27.7-lttng-0.61.orig/ltt/ltt-relay-locked.c	2008-12-03 16:25:22.000000000 +0800
> +++ linux-2.6.27.7-lttng-0.61/ltt/ltt-relay-locked.c	2008-12-12 13:09:21.000000000 +0800
> @@ -78,7 +78,6 @@ struct ltt_channel_buf_struct {
>  					 * Wait queue for blocking user space
>  					 * writers
>  					 */
> -	struct work_struct wake_writers;/* Writers wake-up work struct */
>  	int wakeup_readers;		/* Boolean : wakeup readers waiting ? */
>  } ____cacheline_aligned;
>  
> @@ -233,6 +232,19 @@ static int ltt_remove_buf_file_callback(
>  }
>  
>  /*
> + * Wake writers :
> + *
> + * This must be done after the trace is removed from the RCU list so that there
> + * are no stalled writers.
> + */
> +static void ltt_relay_wake_writers(struct ltt_channel_buf_struct *ltt_buf)
> +{
> +
> +	if (waitqueue_active(&ltt_buf->write_wait))
> +		wake_up_interruptible(&ltt_buf->write_wait);
> +}
> +
> +/*
>   * This function should not be called from NMI interrupt context
>   */
>  static notrace void ltt_buf_unfull(struct rchan_buf *buf,
> @@ -244,8 +256,7 @@ static notrace void ltt_buf_unfull(struc
>  	struct ltt_channel_buf_struct *ltt_buf =
>  		percpu_ptr(ltt_channel->buf, buf->cpu);
>  
> -	if (waitqueue_active(&ltt_buf->write_wait))
> -		schedule_work(&ltt_buf->wake_writers);
> +	ltt_relay_wake_writers(ltt_buf);
>  }
>  
>  /**
> @@ -661,14 +672,6 @@ static void ltt_relay_release_channel(st
>  	kfree(ltt_chan);
>  }
>  
> -static void ltt_wakeup_writers(struct work_struct *work)
> -{
> -	struct ltt_channel_buf_struct *ltt_buf =
> -		container_of(work, struct ltt_channel_buf_struct, wake_writers);
> -
> -	wake_up_interruptible(&ltt_buf->write_wait);
> -}
> -
>  /*
>   * Create ltt buffer.
>   */
> @@ -689,7 +692,6 @@ static int ltt_relay_create_buffer(struc
>  	kref_get(&ltt_chan->kref);
>  	ltt_buf->offset = ltt_subbuffer_header_size();
>  	init_waitqueue_head(&ltt_buf->write_wait);
> -	INIT_WORK(&ltt_buf->wake_writers, ltt_wakeup_writers);
>  
>  	ltt_buffer_begin_callback(buf, trace->start_tsc, 0);
>  	ltt_buf->commit_count[0] += ltt_subbuffer_header_size();
> @@ -844,19 +846,6 @@ static void ltt_relay_async_wakeup_chan(
>  	}
>  }
>  
> -/*
> - * Wake writers :
> - *
> - * This must be done after the trace is removed from the RCU list so that there
> - * are no stalled writers.
> - */
> -static void ltt_relay_wake_writers(struct ltt_channel_buf_struct *ltt_buf)
> -{
> -
> -	if (waitqueue_active(&ltt_buf->write_wait))
> -		schedule_work(&ltt_buf->wake_writers);
> -}
> -
>  static void ltt_relay_finish_buffer(struct ltt_channel_struct *ltt_channel,
>  		unsigned int cpu)
>  {
> 
> 
> 
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> 

-- 
Mathieu Desnoyers
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