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mdbx: refine befree-store inside freelist_save().

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This commit is contained in:
Leonid Yuriev 2018-08-11 02:04:34 +03:00
parent 559e7bc8de
commit 111befb695
1 changed files with 13 additions and 15 deletions
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28
src/mdbx.c
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@ -3525,13 +3525,13 @@ static int mdbx_prep_backlog(MDBX_txn *txn, MDBX_cursor *mc) {
* This changes the freelist. Keep trying until it stabilizes. */
static int mdbx_freelist_save(MDBX_txn *txn) {
/* env->me_reclaimed_pglist[] can grow and shrink during this call.
* env->me_last_reclaimed and txn->mt_free_pages[] can only grow.
* Page numbers cannot disappear from txn->mt_free_pages[]. */
* env->me_last_reclaimed and txn->mt_befree_pages[] can only grow.
* Page numbers cannot disappear from txn->mt_befree_pages[]. */
MDBX_cursor mc;
MDBX_env *env = txn->mt_env;
int rc, more = 1;
txnid_t cleanup_reclaimed_id = 0, head_id = 0;
pgno_t befree_count = 0;
size_t befree_stored = 0;
intptr_t head_room = 0, total_room = 0;
unsigned cleanup_reclaimed_pos = 0, refill_reclaimed_pos = 0;
const bool lifo = (env->me_flags & MDBX_LIFORECLAIM) != 0;
@ -3602,7 +3602,7 @@ again_on_freelist_change:
* The pages themselves remain in dirtylist. */
if (unlikely(!env->me_reclaimed_pglist) &&
!(lifo && env->me_last_reclaimed > 1)) {
/* Put loose page numbers in mt_free_pages,
/* Put loose page numbers in mt_befree_pages,
* since unable to return them to me_reclaimed_pglist. */
if (unlikely((rc = mdbx_pnl_need(&txn->mt_befree_pages,
txn->mt_loose_count)) != 0))
@ -3681,37 +3681,35 @@ again_on_freelist_change:
}
/* Save the PNL of pages freed by this txn, to a single record */
if (befree_count < txn->mt_befree_pages[0]) {
if (unlikely(!befree_count)) {
if (befree_stored < txn->mt_befree_pages[0]) {
if (unlikely(!befree_stored)) {
/* Make sure last page of freeDB is touched and on freelist */
rc = mdbx_page_search(&mc, NULL, MDBX_PS_LAST | MDBX_PS_MODIFY);
if (unlikely(rc && rc != MDBX_NOTFOUND))
goto bailout;
}
pgno_t *befree_pages = txn->mt_befree_pages;
/* Write to last page of freeDB */
key.iov_len = sizeof(txn->mt_txnid);
key.iov_base = &txn->mt_txnid;
do {
befree_count = befree_pages[0];
data.iov_len = MDBX_PNL_SIZEOF(befree_pages);
data.iov_len = MDBX_PNL_SIZEOF(txn->mt_befree_pages);
rc = mdbx_cursor_put(&mc, &key, &data, MDBX_RESERVE);
if (unlikely(rc))
goto bailout;
/* Retry if mt_free_pages[] grew during the Put() */
befree_pages = txn->mt_befree_pages;
} while (befree_count < befree_pages[0]);
} while (data.iov_len < MDBX_PNL_SIZEOF(txn->mt_befree_pages));
mdbx_pnl_sort(befree_pages);
memcpy(data.iov_base, befree_pages, data.iov_len);
befree_stored = txn->mt_befree_pages[0];
mdbx_pnl_sort(txn->mt_befree_pages);
memcpy(data.iov_base, txn->mt_befree_pages, data.iov_len);
if (mdbx_debug_enabled(MDBX_DBG_EXTRA)) {
unsigned i = (unsigned)befree_pages[0];
unsigned i = befree_stored;
mdbx_debug_extra("PNL write txn %" PRIaTXN " root %" PRIaPGNO
" num %u, PNL",
txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i);
for (; i; i--)
mdbx_debug_extra_print(" %" PRIaPGNO "", befree_pages[i]);
mdbx_debug_extra_print(" %" PRIaPGNO "", txn->mt_befree_pages[i]);
mdbx_debug_extra_print("\n");
}
continue;