Commit 2e8d686a authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: Coalesce accounting keys before journal replay 



This fixes a performance regression in journal replay; without
colaescing accounting keys we have multiple keys at the same position,
which means journal_keys_peek_upto() has to skip past many overwritten
keys - turning journal replay into an O(n^2) algorithm.

Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 1d16c605

fs/bcachefs/btree_journal_iter.h

+2 −0
Original line number Diff line number Diff line
@@ -2,6 +2,8 @@ 
#ifndef _BCACHEFS_BTREE_JOURNAL_ITER_H

#define _BCACHEFS_BTREE_JOURNAL_ITER_H



#include "bkey.h"



struct journal_iter {

	struct list_head	list;

	enum btree_id		btree_id;

fs/bcachefs/disk_accounting.c

+18 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 


#include "bcachefs.h"

#include "bcachefs_ioctl.h"

#include "btree_journal_iter.h"

#include "btree_update.h"

#include "btree_write_buffer.h"

#include "buckets.h"
@@ -344,7 +345,9 @@ int bch2_accounting_read(struct bch_fs *c) 
		goto err;



	struct journal_keys *keys = &c->journal_keys;

	struct journal_key *dst = keys->data;

	move_gap(keys, keys->nr);



	darray_for_each(*keys, i) {

		if (i->k->k.type == KEY_TYPE_accounting) {

			struct bkey_s_c k = bkey_i_to_s_c(i->k);
@@ -358,11 +361,26 @@ int bch2_accounting_read(struct bch_fs *c) 
			if (applied)

				continue;



			if (i + 1 < &darray_top(*keys) &&

			    i[1].k->k.type == KEY_TYPE_accounting &&

			    !journal_key_cmp(i, i + 1)) {

				BUG_ON(bversion_cmp(i[0].k->k.version, i[1].k->k.version) >= 0);



				i[1].journal_seq = i[0].journal_seq;



				bch2_accounting_accumulate(bkey_i_to_accounting(i[1].k),

							   bkey_s_c_to_accounting(k));

				continue;

			}



			ret = accounting_read_key(c, k);

			if (ret)

				goto err;

		}



		*dst++ = *i;

	}

	keys->gap = keys->nr = dst - keys->data;



	percpu_down_read(&c->mark_lock);

	preempt_disable();