[Devel] [PATCH RHEL9 COMMIT] dm-ploop: convert high_prio to status
Konstantin Khorenko
khorenko at virtuozzo.com
Mon Jan 27 16:12:43 MSK 2025
The commit is pushed to "branch-rh9-5.14.0-427.44.1.vz9.80.x-ovz" and will appear at git at bitbucket.org:openvz/vzkernel.git
after rh9-5.14.0-427.44.1.vz9.80.6
------>
commit 029e80f45cc232b43c69f982af17a842d577256d
Author: Alexander Atanasov <alexander.atanasov at virtuozzo.com>
Date: Fri Jan 24 17:36:05 2025 +0200
dm-ploop: convert high_prio to status
convert bool high prio to status bit - reduce size and gain atomicity
https://virtuozzo.atlassian.net/browse/VSTOR-91817
Signed-off-by: Alexander Atanasov <alexander.atanasov at 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-bat.c | 1 -
drivers/md/dm-ploop-map.c | 10 +++++-----
drivers/md/dm-ploop.h | 3 +--
3 files changed, 6 insertions(+), 8 deletions(-)
diff --git a/drivers/md/dm-ploop-bat.c b/drivers/md/dm-ploop-bat.c
index 33069d580e87..afbd43d74c6a 100644
--- a/drivers/md/dm-ploop-bat.c
+++ b/drivers/md/dm-ploop-bat.c
@@ -88,7 +88,6 @@ static struct md_page *ploop_alloc_md_page(u32 id)
md->page = page;
md->kmpage = kmap(page);
md->id = id;
- md->high_prio = false;
spin_lock_init(&md->md_lock);
return md;
diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c
index bd80dac34073..55d619cefe50 100644
--- a/drivers/md/dm-ploop-map.c
+++ b/drivers/md/dm-ploop-map.c
@@ -576,10 +576,9 @@ static void ploop_md_up_prio(struct ploop *ploop, struct md_page *md)
write_lock_irqsave(&ploop->bat_rwlock, flags);
if (test_bit(MD_WRITEBACK, &md->status))
goto out;
- if (md->high_prio)
+ if (test_and_set_bit(MD_HIGHPRIO, &md->status))
goto out;
- md->high_prio = true;
WARN_ON_ONCE(!test_bit(MD_DIRTY, &md->status));
out:
write_unlock_irqrestore(&ploop->bat_rwlock, flags);
@@ -1859,15 +1858,16 @@ 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 (!llist_empty(&md->wait_llist) || md->high_prio ||
+ if (!llist_empty(&md->wait_llist) ||
+ 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));
WARN_ON_ONCE(test_bit(MD_WRITEBACK, &md->status));
- md->high_prio = false;
set_bit(MD_WRITEBACK, &md->status);
clear_bit(MD_DIRTY, &md->status);
+ clear_bit(MD_HIGHPRIO, &md->status);
ploop_index_wb_submit(ploop, md->piwb);
} else {
llist_add((struct llist_node *)&md->wb_link, &ploop->wb_batch_llist);
@@ -2025,7 +2025,7 @@ static int ploop_prepare_flush(struct ploop *ploop, struct pio *pio)
md = list_entry((struct list_head *)pos, typeof(*md), wb_link);
md_inflight++;
md->piwb->flush_pio = flush_pio;
- md->high_prio = true;
+ set_bit(MD_HIGHPRIO, &md->status);
}
atomic_set(&flush_pio->md_inflight, md_inflight);
diff --git a/drivers/md/dm-ploop.h b/drivers/md/dm-ploop.h
index 91176b3d8b35..bf4b15ddd69a 100644
--- a/drivers/md/dm-ploop.h
+++ b/drivers/md/dm-ploop.h
@@ -117,6 +117,7 @@ struct md_page {
u32 id; /* Number of this page starting from hdr */
#define MD_DIRTY (1U << 1) /* Page contains changes and wants writeback */
#define MD_WRITEBACK (1U << 2) /* Writeback was submitted */
+#define MD_HIGHPRIO (1U << 3) /* High priority writeback */
unsigned long status;
struct page *page;
void *kmpage;
@@ -127,8 +128,6 @@ struct md_page {
struct ploop_index_wb *piwb;
spinlock_t md_lock;
-
- bool high_prio;
unsigned long dirty_timeout;
};
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