On Tue, 07 Jun 2016 05:41:48 +0200,
Bhaktipriya Shridhar wrote:
>
> System workqueues have been able to handle high level of concurrency
> for a long time now and there's no reason to use dedicated workqueues
> just to gain concurrency. Since aica_queue for AICA sound
> driver has workitem dreamcastcard->spu_dma_work (maps to run_spu_dma)
> which is involved in aica dma transfers and is not being used on a memory
> reclaim path, dedicated aica_queue has been replaced with the
> use of system_wq.
>
> Unlike a dedicated per-cpu workqueue created with create_workqueue(),
> system_wq allows multiple work items to overlap executions even on
> the same CPU; however, a per-cpu workqueue doesn't have any CPU
> locality or global ordering guarantees unless the target CPU is
> explicitly specified and thus the increase of local concurrency
> shouldn't make any difference.
>
> Since the work items could be pending, flush_work() has been used in
> snd_aicapcm_pcm_close() to ensure that there is no pending task while
> disconnecting the driver.
>
> Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@xxxxxxxxx>
Applied, thanks.
Takashi
> ---
> sound/sh/aica.c | 16 +++-------------
> 1 file changed, 3 insertions(+), 13 deletions(-)
>
> diff --git a/sound/sh/aica.c b/sound/sh/aica.c
> index ad3d9ae..fbbc252 100644
> --- a/sound/sh/aica.c
> +++ b/sound/sh/aica.c
> @@ -63,9 +63,6 @@ MODULE_PARM_DESC(id, "ID string for " CARD_NAME " soundcard.");
> module_param(enable, bool, 0644);
> MODULE_PARM_DESC(enable, "Enable " CARD_NAME " soundcard.");
>
> -/* Use workqueue */
> -static struct workqueue_struct *aica_queue;
> -
> /* Simple platform device */
> static struct platform_device *pd;
> static struct resource aica_memory_space[2] = {
> @@ -327,7 +324,7 @@ static void aica_period_elapsed(unsigned long timer_var)
> dreamcastcard->current_period = play_period;
> if (unlikely(dreamcastcard->dma_check == 0))
> dreamcastcard->dma_check = 1;
> - queue_work(aica_queue, &(dreamcastcard->spu_dma_work));
> + schedule_work(&(dreamcastcard->spu_dma_work));
> }
>
> static void spu_begin_dma(struct snd_pcm_substream *substream)
> @@ -337,7 +334,7 @@ static void spu_begin_dma(struct snd_pcm_substream *substream)
> runtime = substream->runtime;
> dreamcastcard = substream->pcm->private_data;
> /*get the queue to do the work */
> - queue_work(aica_queue, &(dreamcastcard->spu_dma_work));
> + schedule_work(&(dreamcastcard->spu_dma_work));
> /* Timer may already be running */
> if (unlikely(dreamcastcard->timer.data)) {
> mod_timer(&dreamcastcard->timer, jiffies + 4);
> @@ -381,7 +378,7 @@ static int snd_aicapcm_pcm_close(struct snd_pcm_substream
> *substream)
> {
> struct snd_card_aica *dreamcastcard = substream->pcm->private_data;
> - flush_workqueue(aica_queue);
> + flush_work(&(dreamcastcard->spu_dma_work));
> if (dreamcastcard->timer.data)
> del_timer(&dreamcastcard->timer);
> kfree(dreamcastcard->channel);
> @@ -633,9 +630,6 @@ static int snd_aica_probe(struct platform_device *devptr)
> if (unlikely(err < 0))
> goto freedreamcast;
> platform_set_drvdata(devptr, dreamcastcard);
> - aica_queue = create_workqueue(CARD_NAME);
> - if (unlikely(!aica_queue))
> - goto freedreamcast;
> snd_printk
> ("ALSA Driver for Yamaha AICA Super Intelligent Sound Processor\n");
> return 0;
> @@ -671,10 +665,6 @@ static int __init aica_init(void)
>
> static void __exit aica_exit(void)
> {
> - /* Destroy the aica kernel thread *
> - * being extra cautious to check if it exists*/
> - if (likely(aica_queue))
> - destroy_workqueue(aica_queue);
> platform_device_unregister(pd);
> platform_driver_unregister(&snd_aica_driver);
> /* Kill any sound still playing and reset ARM7 to safe state */
> --
> 2.1.4
>
>
_______________________________________________
Alsa-devel mailing list
Alsa-devel@xxxxxxxxxxxxxxxx
http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
