Re: [PATCH 6/6] UBI: Fastmap: Make ubi_refill_pools() fair

[Guido Martínez]

Hi Richard,

On Mon, Nov 24, 2014 at 02:20:36PM +0100, Richard Weinberger wrote:
> Currently ubi_refill_pools() first fills the first and then
> the second one.
> If only very few free PEBs are available the second pool can get
> zero PEBs.
> Change ubi_refill_pools() to distribute free PEBs fair between
> all pools.
> 
> Signed-off-by: Richard Weinberger <richard@xxxxxx>
Reviewed-by: Guido Martínez <guido@xxxxxxxxxxxxxxxxxxxx>

> ---
>  drivers/mtd/ubi/wl.c | 77 +++++++++++++++++++++++++++-------------------------
>  1 file changed, 40 insertions(+), 37 deletions(-)
> 
> diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
> index f028b68..c2822f7 100644
> --- a/drivers/mtd/ubi/wl.c
> +++ b/drivers/mtd/ubi/wl.c
> @@ -583,59 +583,62 @@ static void return_unused_pool_pebs(struct ubi_device *ubi,
>  }
>  
>  /**
> - * refill_wl_pool - refills all the fastmap pool used by the
> - * WL sub-system.
> + * ubi_refill_pools - refills all fastmap PEB pools.
>   * @ubi: UBI device description object
>   */
> -static void refill_wl_pool(struct ubi_device *ubi)
> +void ubi_refill_pools(struct ubi_device *ubi)
>  {
> +	struct ubi_fm_pool *wl_pool = &ubi->fm_wl_pool;
> +	struct ubi_fm_pool *pool = &ubi->fm_pool;
>  	struct ubi_wl_entry *e;
> -	struct ubi_fm_pool *pool = &ubi->fm_wl_pool;
> +	int enough;
>  
> +	spin_lock(&ubi->wl_lock);
> +
> +	return_unused_pool_pebs(ubi, wl_pool);
>  	return_unused_pool_pebs(ubi, pool);
>  
> -	for (pool->size = 0; pool->size < pool->max_size; pool->size++) {
> -		if (!ubi->free.rb_node ||
> -		   (ubi->free_count - ubi->beb_rsvd_pebs < 5))
> -			break;
> +	wl_pool->size = 0;
> +	pool->size = 0;
>  
> -		e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
> -		self_check_in_wl_tree(ubi, e, &ubi->free);
> -		rb_erase(&e->u.rb, &ubi->free);
> -		ubi->free_count--;
> +	for (;;) {
> +		enough = 0;
> +		if (pool->size < pool->max_size) {
> +			if (!ubi->free.rb_node ||
> +			   (ubi->free_count - ubi->beb_rsvd_pebs < 5))
> +				break;
>  
> -		pool->pebs[pool->size] = e->pnum;
> -	}
> -	pool->used = 0;
> -}
> +			e = wl_get_wle(ubi);
> +			if (!e)
> +				break;
>  
> -/**
> - * refill_wl_user_pool - refills all the fastmap pool used by ubi_wl_get_peb.
> - * @ubi: UBI device description object
> - */
> -static void refill_wl_user_pool(struct ubi_device *ubi)
> -{
> -	struct ubi_fm_pool *pool = &ubi->fm_pool;
> +			pool->pebs[pool->size] = e->pnum;
> +			pool->size++;
> +		} else
> +			enough++;
>  
> -	return_unused_pool_pebs(ubi, pool);
> +		if (wl_pool->size < wl_pool->max_size) {
> +			if (!ubi->free.rb_node ||
> +			   (ubi->free_count - ubi->beb_rsvd_pebs < 5))
> +				break;
>  
> -	for (pool->size = 0; pool->size < pool->max_size; pool->size++) {
> -		pool->pebs[pool->size] = __wl_get_peb(ubi);
> -		if (pool->pebs[pool->size] < 0)
> +			e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
> +			self_check_in_wl_tree(ubi, e, &ubi->free);
> +			rb_erase(&e->u.rb, &ubi->free);
> +			ubi->free_count--;
> +
> +			wl_pool->pebs[wl_pool->size] = e->pnum;
> +			wl_pool->size++;
> +		} else
> +			enough++;
> +
> +		if (enough == 2)
>  			break;
>  	}
> +
> +	wl_pool->used = 0;
>  	pool->used = 0;
> -}
>  
> -/**
> - * ubi_refill_pools - refills all fastmap PEB pools.
> - * @ubi: UBI device description object
> - */
> -void ubi_refill_pools(struct ubi_device *ubi)
> -{
> -	spin_lock(&ubi->wl_lock);
> -	refill_wl_pool(ubi);
> -	refill_wl_user_pool(ubi);
>  	spin_unlock(&ubi->wl_lock);
>  }
>  
> -- 
> 1.8.4.5
> 
> --
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-- 
Guido Martínez, VanguardiaSur
www.vanguardiasur.com.ar
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