From: Alexander Atanasov <alexander.atana...@virtuozzo.com>
https://virtuozzo.atlassian.net/browse/VSTOR-91820
Signed-off-by: Alexander Atanasov <alexander.atana...@virtuozzo.com>
======
Patchset description:
ploop: optimistations and scalling
Ploop processes requsts in a different threads in parallel
where possible which results in significant improvement in
performance and makes further optimistations possible.
Known bugs:
- delayed metadata writeback is not working and is missing error handling
- patch to disable it until fixed
- fast path is not working - causes rcu lockups - patch to disable it
Further improvements:
- optimize md pages lookups
Alexander Atanasov (50):
dm-ploop: md_pages map all pages at creation time
dm-ploop: Use READ_ONCE/WRITE_ONCE to access md page data
dm-ploop: fsync after all pios are sent
dm-ploop: move md status to use proper bitops
dm-ploop: convert wait_list and wb_batch_llist to use lockless lists
dm-ploop: convert enospc handling to use lockless lists
dm-ploop: convert suspended_pios list to use lockless list
dm-ploop: convert the rest of the lists to use llist variant
dm-ploop: combine processing of pios thru prepare list and remove
fsync worker
dm-ploop: move from wq to kthread
dm-ploop: move preparations of pios into the caller from worker
dm-ploop: fast path execution for reads
dm-ploop: do not use a wrapper for set_bit to make a page writeback
dm-ploop: BAT use only one list for writeback
dm-ploop: make md writeback timeout to be per page
dm-ploop: add interface to disable bat writeback delay
dm-ploop: convert wb_batch_list to lockless variant
dm-ploop: convert high_prio to status
dm-ploop: split cow processing into two functions
dm-ploop: convert md page rw lock to spin lock
dm-ploop: convert bat_rwlock to bat_lock spinlock
dm-ploop: prepare bat updates under bat_lock
dm-ploop: make ploop_bat_write_complete ready for parallel pio
completion
dm-ploop: make ploop_submit_metadata_writeback return number of
requests sent
dm-ploop: introduce pio runner threads
dm-ploop: add pio list ids to be used when passing pios to runners
dm-ploop: process pios via runners
dm-ploop: disable metadata writeback delay
dm-ploop: disable fast path
dm-ploop: use lockless lists for chained cow updates list
dm-ploop: use lockless lists for data ready pios
dm-ploop: give runner threads better name
dm-ploop: resize operation - add holes bitmap locking
dm-ploop: remove unnecessary operations
dm-ploop: use filp per thread
dm-ploop: catch if we try to advance pio past bio end
dm-ploop: support REQ_FUA for data pios
dm-ploop: proplerly access nr_bat_entries
dm-ploop: fix locking and improve error handling when submitting pios
dm-ploop: fix how ENOTBLK is handled
dm-ploop: sync when suspended or stopping
dm-ploop: rework bat completion logic
dm-ploop: rework logic in pio processing
dm-ploop: end fsync pios in parallel
dm-ploop: make filespace preallocations async
dm-ploop: resubmit enospc pios from dispatcher thread
dm-ploop: dm-ploop: simplify discard completion
dm-ploop: use GFP_ATOMIC instead of GFP_NOIO
dm-ploop: fix locks used in mixed context
dm-ploop: fix how current flags are managed inside threads
Andrey Zhadchenko (13):
dm-ploop: do not flush after metadata writes
dm-ploop: set IOCB_DSYNC on all FUA requests
dm-ploop: remove extra ploop_cluster_is_in_top_delta()
dm-ploop: introduce per-md page locking
dm-ploop: reduce BAT accesses on discard completion
dm-ploop: simplify llseek
dm-ploop: speed up ploop_prepare_bat_update()
dm-ploop: make new allocations immediately visible in BAT
dm-ploop: drop ploop_cluster_is_in_top_delta()
dm-ploop: do not wait for BAT update for non-FUA requests
dm-ploop: add delay for metadata writeback
dm-ploop: submit all postponed metadata on REQ_OP_FLUSH
dm-ploop: handle REQ_PREFLUSH
Feature: dm-ploop: ploop target driver
---
drivers/md/dm-ploop-map.c | 21 +++++++++++++--------
drivers/md/dm-ploop-target.c | 3 ++-
drivers/md/dm-ploop.h | 2 +-
3 files changed, 16 insertions(+), 10 deletions(-)
diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c
index fa8cb0c44f8c..591388ca6ae8 100644
--- a/drivers/md/dm-ploop-map.c
+++ b/drivers/md/dm-ploop-map.c
@@ -143,14 +143,19 @@ static void ploop_init_prq_and_embedded_pio(struct ploop
*ploop,
void ploop_enospc_timer(struct timer_list *timer)
{
struct ploop *ploop = from_timer(ploop, timer, enospc_timer);
- unsigned long flags;
LIST_HEAD(list);
+ struct llist_node *pos, *t;
+ struct llist_node *enospc_pending = llist_del_all(&ploop->enospc_pios);
- spin_lock_irqsave(&ploop->deferred_lock, flags);
- list_splice_init(&ploop->enospc_pios, &list);
- spin_unlock_irqrestore(&ploop->deferred_lock, flags);
+ if (enospc_pending) {
+ enospc_pending = llist_reverse_order(enospc_pending);
+ llist_for_each_safe(pos, t, enospc_pending) {
+ struct pio *pio = llist_entry(pos, typeof(*pio), llist);
- ploop_submit_embedded_pios(ploop, &list);
+ list_add(&pio->list, &list);
+ }
+ ploop_submit_embedded_pios(ploop, &list);
+ }
}
void do_ploop_event_work(struct work_struct *ws)
@@ -166,7 +171,6 @@ static bool ploop_try_delay_enospc(struct ploop_rq *prq,
struct pio *pio)
bool delayed = true;
unsigned long flags;
- spin_lock_irqsave(&ploop->deferred_lock, flags);
if (unlikely(ploop->wants_suspend)) {
delayed = false;
goto unlock;
@@ -176,10 +180,11 @@ static bool ploop_try_delay_enospc(struct ploop_rq *prq,
struct pio *pio)
pr_err_once(PL_FMT("underlying disk is almost full"),
ploop_device_name(ploop));
+ spin_lock_irqsave(&ploop->deferred_lock, flags);
ploop->event_enospc = true;
- list_add_tail(&pio->list, &ploop->enospc_pios);
-unlock:
spin_unlock_irqrestore(&ploop->deferred_lock, flags);
+ llist_add(&pio->llist, &ploop->enospc_pios);
+unlock:
if (delayed)
mod_timer(&ploop->enospc_timer, jiffies + PLOOP_ENOSPC_TIMEOUT);
diff --git a/drivers/md/dm-ploop-target.c b/drivers/md/dm-ploop-target.c
index b66ae3a9a4b0..3ac9e1f832f5 100644
--- a/drivers/md/dm-ploop-target.c
+++ b/drivers/md/dm-ploop-target.c
@@ -376,7 +376,8 @@ static int ploop_ctr(struct dm_target *ti, unsigned int
argc, char **argv)
INIT_LIST_HEAD(&ploop->pios[i]);
INIT_LIST_HEAD(&ploop->resubmit_pios);
- INIT_LIST_HEAD(&ploop->enospc_pios);
+ init_llist_head(&ploop->enospc_pios);
+
INIT_LIST_HEAD(&ploop->cluster_lk_list);
init_llist_head(&ploop->wb_batch_llist);
ploop->bat_entries = RB_ROOT;
diff --git a/drivers/md/dm-ploop.h b/drivers/md/dm-ploop.h
index d459a02ded5d..86eff6546f91 100644
--- a/drivers/md/dm-ploop.h
+++ b/drivers/md/dm-ploop.h
@@ -198,7 +198,7 @@ struct ploop {
struct list_head pios[PLOOP_LIST_COUNT];
struct list_head resubmit_pios; /* After partial IO */
- struct list_head enospc_pios; /* Delayed after ENOSPC */
+ struct llist_head enospc_pios; /* Delayed after ENOSPC */
atomic_t service_pios;
struct wait_queue_head service_wq;
--
2.43.5
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