[Devel] [PATCH vz9 v2 30/65] dm-ploop: make md writeback timeout to be per page
Konstantin Khorenko
khorenko at virtuozzo.com
Wed Feb 12 12:33:23 MSK 2025
From: Alexander Atanasov <alexander.atanasov at virtuozzo.com>
Do not bulk write all dirtied bat pages in a common timeout.
Instead mark dirty time for each page and delay for each page
by the timeout. If page is tried to be redirtied - update the
dirty time so for hot page try to accumulate more changes before
writeout.
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-map.c | 10 ++++------
drivers/md/dm-ploop.h | 1 +
2 files changed, 5 insertions(+), 6 deletions(-)
diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c
index f2e0d0b317de..cc2f5176a7e4 100644
--- a/drivers/md/dm-ploop-map.c
+++ b/drivers/md/dm-ploop-map.c
@@ -564,6 +564,8 @@ static bool ploop_md_make_dirty(struct ploop *ploop, struct md_page *md)
new = true;
}
write_unlock_irqrestore(&ploop->bat_rwlock, flags);
+ md->dirty_timeout = jiffies + ploop->md_submit_delay_ms*HZ/1000;
+
return new;
}
@@ -1827,14 +1829,10 @@ static void ploop_process_resubmit_pios(struct ploop *ploop,
static void ploop_submit_metadata_writeback(struct ploop *ploop)
{
- ktime_t ktime, ktimeout;
LIST_HEAD(ll_skipped);
struct md_page *md, *mtmp;
- int send_all;
+ unsigned long timeout = jiffies;
- ktime = ktime_get();
- ktimeout = ktime_add_ms(ktime, ploop->md_submit_delay_ms);
- send_all = ktime_after(ktime, ktimeout);
/*
* Pages are set dirty so no one must touch lists
* if new md entries are dirtied they are added at the start of the list
@@ -1842,7 +1840,7 @@ static void ploop_submit_metadata_writeback(struct ploop *ploop)
list_for_each_entry_safe(md, mtmp, &ploop->wb_batch_list, wb_link) {
write_lock_irq(&ploop->bat_rwlock);
list_del_init(&md->wb_link);
- if (md->high_prio || send_all) {
+ if (md->high_prio || time_before(md->dirty_timeout, timeout)) {
/* 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));
diff --git a/drivers/md/dm-ploop.h b/drivers/md/dm-ploop.h
index 909ddf877a7f..e504b83e40d3 100644
--- a/drivers/md/dm-ploop.h
+++ b/drivers/md/dm-ploop.h
@@ -129,6 +129,7 @@ struct md_page {
spinlock_t md_lock;
bool high_prio;
+ unsigned long dirty_timeout;
};
enum {
--
2.43.5
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