reduce locking for cow pios chained to bat updates
https://virtuozzo.atlassian.net/browse/VSTOR-91821
Signed-off-by: Alexander Atanasov <alexander.atana...@virtuozzo.com>
---
drivers/md/dm-ploop-map.c | 19 ++++++++++---------
drivers/md/dm-ploop.h | 2 +-
2 files changed, 11 insertions(+), 10 deletions(-)
diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c
index dcdbc509c54e..809ae3ee71ec 100644
--- a/drivers/md/dm-ploop-map.c
+++ b/drivers/md/dm-ploop-map.c
@@ -63,7 +63,8 @@ void ploop_index_wb_init(struct ploop_index_wb *piwb, struct
ploop *ploop)
piwb->bat_page = NULL;
piwb->bi_status = 0;
INIT_LIST_HEAD(&piwb->ready_data_pios);
- INIT_LIST_HEAD(&piwb->cow_list);
+ init_llist_head(&piwb->cow_llist);
+
/* For ploop_bat_write_complete() */
atomic_set(&piwb->count, 1);
piwb->completed = false;
@@ -901,7 +902,8 @@ static void ploop_bat_write_complete(struct pio *pio, void
*piwb_ptr,
struct pio *data_pio;
unsigned long flags;
LIST_HEAD(lready_pios);
- LIST_HEAD(lcow_pios);
+ struct llist_node *pos, *t;
+ struct llist_node *ll_cow_pios;
int completed = atomic_read(&piwb->count) == 1;
if (completed) {
@@ -926,9 +928,7 @@ static void ploop_bat_write_complete(struct pio *pio, void
*piwb_ptr,
list_splice_init(&piwb->ready_data_pios, &lready_pios);
spin_unlock_irqrestore(&piwb->lock, flags);
- spin_lock_irqsave(&ploop->deferred_lock, flags);
- list_splice_init(&piwb->cow_list, &lcow_pios);
- spin_unlock_irqrestore(&ploop->deferred_lock, flags);
+ ll_cow_pios = llist_reverse_order(llist_del_all(&piwb->cow_llist));
/*
* End pending data bios.
@@ -940,7 +940,9 @@ static void ploop_bat_write_complete(struct pio *pio, void
*piwb_ptr,
ploop_pio_endio(data_pio);
}
- while ((aux_pio = ploop_pio_list_pop(&lcow_pios))) {
+ llist_for_each_safe(pos, t, ll_cow_pios) {
+ aux_pio = list_entry((struct list_head *)pos, typeof(*aux_pio),
list);
+ INIT_LIST_HEAD(&aux_pio->list);
cow = aux_pio->endio_cb_data;
ploop_complete_cow(cow, bi_status);
}
@@ -1508,9 +1510,8 @@ static void ploop_submit_cow_index_wb(struct ploop_cow
*cow)
#endif
/* Prevent double clearing of holes_bitmap bit on complete_cow() */
cow->dst_clu = BAT_ENTRY_NONE;
- spin_lock_irq(&ploop->deferred_lock);
- list_add_tail(&cow->aux_pio->list, &piwb->cow_list);
- spin_unlock_irq(&ploop->deferred_lock);
+
+ llist_add((struct llist_node *)(&cow->aux_pio->list), &piwb->cow_llist);
out:
return;
err_resource:
diff --git a/drivers/md/dm-ploop.h b/drivers/md/dm-ploop.h
index 224f4915d9f1..3f80d1750ffb 100644
--- a/drivers/md/dm-ploop.h
+++ b/drivers/md/dm-ploop.h
@@ -102,7 +102,7 @@ struct ploop_index_wb {
struct pio *pio;
struct page *bat_page;
struct list_head ready_data_pios;
- struct list_head cow_list;
+ struct llist_head cow_llist;
atomic_t count;
bool completed;
blk_status_t bi_status;
--
2.43.0
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