[dm-devel] [PATCH 14/15] dm-zoned: select reclaim zone based on device index

[Damien Le Moal]

On Wed, 2020-05-27 at 08:22 +0200, Hannes Reinecke wrote:
> per-device reclaim should select zones on that device only.
> 
> Signed-off-by: Hannes Reinecke <hare at suse.de>
> ---
>  drivers/md/dm-zoned-metadata.c | 50 +++++++++++++++++-------------------------
>  drivers/md/dm-zoned-reclaim.c  |  3 ++-
>  drivers/md/dm-zoned-target.c   |  1 +
>  drivers/md/dm-zoned.h          |  5 ++++-
>  4 files changed, 27 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/md/dm-zoned-metadata.c b/drivers/md/dm-zoned-metadata.c
> index 0d65af94309a..b89b3d3b9ec9 100644
> --- a/drivers/md/dm-zoned-metadata.c
> +++ b/drivers/md/dm-zoned-metadata.c
> @@ -1933,7 +1933,7 @@ static void dmz_wait_for_reclaim(struct dmz_metadata *zmd, struct dm_zone *zone)
>   * Select a cache or random write zone for reclaim.
>   */
>  static struct dm_zone *dmz_get_rnd_zone_for_reclaim(struct dmz_metadata *zmd,
> -						    bool idle)
> +						    unsigned int idx, bool idle)
>  {
>  	struct dm_zone *dzone = NULL;
>  	struct dm_zone *zone;
> @@ -1943,24 +1943,17 @@ static struct dm_zone *dmz_get_rnd_zone_for_reclaim(struct dmz_metadata *zmd,
>  	if (zmd->nr_cache) {
>  		zone_list = &zmd->map_cache_list;
>  		/* Try to relaim random zones, too, when idle */
> -		if (idle && list_empty(zone_list)) {
> -			int i;
> -
> -			for (i = 1; i < zmd->nr_devs; i++) {
> -				zone_list = &zmd->dev[i].map_rnd_list;
> -				if (!list_empty(zone_list))
> -					break;
> -			}
> -		}
> -	} else {
> -		/* Otherwise the random zones are on the first disk */
> -		zone_list = &zmd->dev[0].map_rnd_list;
> -	}
> +		if (idle && list_empty(zone_list))
> +			zone_list = &zmd->dev[idx].map_rnd_list;
> +	} else
> +		zone_list = &zmd->dev[idx].map_rnd_list;
>  
>  	list_for_each_entry(zone, zone_list, link) {
> -		if (dmz_is_buf(zone))
> +		if (dmz_is_buf(zone)) {
>  			dzone = zone->bzone;
> -		else
> +			if (dzone->dev->dev_idx != idx)
> +				continue;
> +		} else
>  			dzone = zone;
>  		if (dmz_lock_zone_reclaim(dzone))
>  			return dzone;
> @@ -1972,20 +1965,16 @@ static struct dm_zone *dmz_get_rnd_zone_for_reclaim(struct dmz_metadata *zmd,
>  /*
>   * Select a buffered sequential zone for reclaim.
>   */
> -static struct dm_zone *dmz_get_seq_zone_for_reclaim(struct dmz_metadata *zmd)
> +static struct dm_zone *dmz_get_seq_zone_for_reclaim(struct dmz_metadata *zmd,
> +						    unsigned int idx)
>  {
>  	struct dm_zone *zone;
> -	int i;
> -
> -	for (i = 0; i < zmd->nr_devs; i++) {
> -		struct dmz_dev *dev = &zmd->dev[i];
>  
> -		list_for_each_entry(zone, &dev->map_seq_list, link) {
> -			if (!zone->bzone)
> -				continue;
> -			if (dmz_lock_zone_reclaim(zone))
> -				return zone;
> -		}
> +	list_for_each_entry(zone, &zmd->dev[idx].map_seq_list, link) {
> +		if (!zone->bzone)
> +			continue;
> +		if (dmz_lock_zone_reclaim(zone))
> +			return zone;
>  	}
>  
>  	return NULL;
> @@ -1994,7 +1983,8 @@ static struct dm_zone *dmz_get_seq_zone_for_reclaim(struct dmz_metadata *zmd)
>  /*
>   * Select a zone for reclaim.
>   */
> -struct dm_zone *dmz_get_zone_for_reclaim(struct dmz_metadata *zmd, bool idle)
> +struct dm_zone *dmz_get_zone_for_reclaim(struct dmz_metadata *zmd,
> +					 unsigned int dev_idx, bool idle)
>  {
>  	struct dm_zone *zone;
>  
> @@ -2008,9 +1998,9 @@ struct dm_zone *dmz_get_zone_for_reclaim(struct dmz_metadata *zmd, bool idle)
>  	 */
>  	dmz_lock_map(zmd);
>  	if (list_empty(&zmd->reserved_seq_zones_list))
> -		zone = dmz_get_seq_zone_for_reclaim(zmd);
> +		zone = dmz_get_seq_zone_for_reclaim(zmd, dev_idx);
>  	else
> -		zone = dmz_get_rnd_zone_for_reclaim(zmd, idle);
> +		zone = dmz_get_rnd_zone_for_reclaim(zmd, dev_idx, idle);
>  	dmz_unlock_map(zmd);
>  
>  	return zone;
> diff --git a/drivers/md/dm-zoned-reclaim.c b/drivers/md/dm-zoned-reclaim.c
> index 5a04e34d17a9..2261b4dd60b7 100644
> --- a/drivers/md/dm-zoned-reclaim.c
> +++ b/drivers/md/dm-zoned-reclaim.c
> @@ -370,7 +370,8 @@ static int dmz_do_reclaim(struct dmz_reclaim *zrc)
>  	int ret;
>  
>  	/* Get a data zone */
> -	dzone = dmz_get_zone_for_reclaim(zmd, dmz_target_idle(zrc));
> +	dzone = dmz_get_zone_for_reclaim(zmd, zrc->dev_idx,
> +					 dmz_target_idle(zrc));
>  	if (!dzone) {
>  		DMDEBUG("(%s/%u): No zone found to reclaim",
>  			dmz_metadata_label(zmd), zrc->dev_idx);
> diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c
> index 4a51738d4b0d..a23f1fbd208f 100644
> --- a/drivers/md/dm-zoned-target.c
> +++ b/drivers/md/dm-zoned-target.c
> @@ -738,6 +738,7 @@ static int dmz_get_zoned_device(struct dm_target *ti, char *path,
>  		dev = &dmz->dev[idx];
>  	}
>  	dev->bdev = bdev;
> +	dev->dev_idx = idx;
>  	(void)bdevname(dev->bdev, dev->name);
>  
>  	dev->capacity = i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
> diff --git a/drivers/md/dm-zoned.h b/drivers/md/dm-zoned.h
> index ec020bb1caf7..22f11440b423 100644
> --- a/drivers/md/dm-zoned.h
> +++ b/drivers/md/dm-zoned.h
> @@ -61,6 +61,8 @@ struct dmz_dev {
>  
>  	sector_t		capacity;
>  
> +	unsigned int		dev_idx;
> +
>  	unsigned int		nr_zones;
>  	unsigned int		zone_offset;
>  
> @@ -243,7 +245,8 @@ static inline void dmz_activate_zone(struct dm_zone *zone)
>  
>  int dmz_lock_zone_reclaim(struct dm_zone *zone);
>  void dmz_unlock_zone_reclaim(struct dm_zone *zone);
> -struct dm_zone *dmz_get_zone_for_reclaim(struct dmz_metadata *zmd, bool idle);
> +struct dm_zone *dmz_get_zone_for_reclaim(struct dmz_metadata *zmd,
> +					 unsigned int dev_idx, bool idle);
>  
>  struct dm_zone *dmz_get_chunk_mapping(struct dmz_metadata *zmd,
>  				      unsigned int chunk, int op);

Looks good.

Reviewed-by: Damien Le Moal <damien.lemoal at wdc.com>

-- 
Damien Le Moal
Western Digital Research