[Devel] [RFC PATCH vz9 v6 36/62] dm-ploop: use jiffies when calculating writeback time

[Andrey Zhadchenko]

Should be merged with writeback timeout patch

On 12/5/24 22:56, Alexander Atanasov wrote:
> ktime_* are expnsive functions, we do not need ns precision.
> using jiffies is fine.
> 
> https://virtuozzo.atlassian.net/browse/VSTOR-91821
> Signed-off-by: Alexander Atanasov <alexander.atanasov at virtuozzo.com>
> ---
>   drivers/md/dm-ploop-map.c | 9 ++++-----
>   drivers/md/dm-ploop.h     | 2 +-
>   2 files changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c
> index e7d5ddd10615..3a741bb9d2db 100644
> --- a/drivers/md/dm-ploop-map.c
> +++ b/drivers/md/dm-ploop-map.c
> @@ -557,12 +557,13 @@ static bool ploop_md_make_dirty(struct ploop *ploop, struct md_page *md)
>   
>   	write_lock_irqsave(&ploop->bat_rwlock, flags);
>   	WARN_ON_ONCE(test_bit(MD_WRITEBACK, &md->status));
> -	md->dirty_time = ktime_get();
>   	if (!test_and_set_bit(MD_DIRTY, &md->status)) {
>   		llist_add((struct llist_node *)&md->wb_link, &ploop->wb_batch_llist);
>   		new = true;
>   	}
>   	write_unlock_irqrestore(&ploop->bat_rwlock, flags);
> +	md->dirty_timeout = jiffies + ploop->md_submit_delay_ms*HZ/1000;
> +
>   	return new;
>   }
>   
> @@ -1835,9 +1836,8 @@ static void ploop_submit_metadata_writeback(struct ploop *ploop)
>   	struct md_page *md;
>   	struct llist_node *pos, *t;
>   	struct llist_node *ll_wb_batch;
> +	unsigned long timeout = jiffies;
>   
> -	ktime = ktime_get();
> -	ktimeout = ktime_add_ms(ktime, ploop->md_submit_delay_ms);
>   	/* Lock here to protect against md_inflight counting */
>   	write_lock_irq(&ploop->bat_rwlock);
>   	ll_wb_batch = llist_del_all(&ploop->wb_batch_llist);
> @@ -1848,8 +1848,7 @@ static void ploop_submit_metadata_writeback(struct ploop *ploop)
>   	 */
>   	llist_for_each_safe(pos, t, ll_wb_batch) {
>   		md = list_entry((struct list_head *)pos, typeof(*md), wb_link);
> -		INIT_LIST_HEAD(&md->wb_link);
> -		if (test_bit(MD_HIGHPRIO, &md->status) || ktime_after(md->dirty_time, ktimeout)
> +		if (test_bit(MD_HIGHPRIO, &md->status) || time_before(md->dirty_timeout, timeout)
>   		    || ploop->force_md_writeback) {
>   			/* L1L2 mustn't be redirtyed, when wb in-flight! */
>   			WARN_ON_ONCE(!test_bit(MD_DIRTY, &md->status));
> diff --git a/drivers/md/dm-ploop.h b/drivers/md/dm-ploop.h
> index 8dfd75e97845..3c632eab37d7 100644
> --- a/drivers/md/dm-ploop.h
> +++ b/drivers/md/dm-ploop.h
> @@ -130,7 +130,7 @@ struct md_page {
>   
>   	rwlock_t lock;
>   
> -	ktime_t dirty_time;
> +	unsigned long dirty_timeout;
>   };
>   
>   enum {