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mdbx: rework mdbx_page_alloc().

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Change-Id: I5c6e2ef23abf79096dd699f9dfbecf97bfc4fe37
This commit is contained in:
Leonid Yuriev 2021-01-15 17:35:14 +03:00
parent 764dab90fc
commit 4afc30c79f
1 changed files with 29 additions and 51 deletions
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80
src/core.c
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@ -5149,21 +5149,27 @@ static __inline txnid_t pp_txnid2chk(const MDBX_txn *txn) {
__hot static int mdbx_page_alloc(MDBX_cursor *mc, const unsigned num,
MDBX_page **const mp, int flags) {
int rc;
MDBX_txn *txn = mc->mc_txn;
MDBX_env *env = txn->mt_env;
MDBX_txn *const txn = mc->mc_txn;
MDBX_env *const env = txn->mt_env;
MDBX_page *np;
const unsigned coalesce_threshold =
env->me_maxgc_ov1page - env->me_maxgc_ov1page / 4;
if (likely(flags & MDBX_ALLOC_GC)) {
flags |= env->me_flags & (MDBX_COALESCE | MDBX_LIFORECLAIM);
if (unlikely(mc->mc_flags & C_RECLAIMING)) {
/* If mc is updating the GC, then the retired-list cannot play
* catch-up with itself by growing while trying to save it. */
flags &= ~MDBX_ALLOC_GC;
} else if (unlikely(txn->mt_dbs[FREE_DBI].md_entries == 0)) {
/* avoid (recursive) search inside empty tree and while tree is updating,
* https://github.com/erthink/libmdbx/issues/31 */
flags &= ~MDBX_ALLOC_GC;
}
if (MDBX_PNL_SIZE(txn->tw.reclaimed_pglist) > coalesce_threshold)
flags &= ~MDBX_COALESCE;
if (unlikely(
/* If mc is updating the GC, then the retired-list cannot play
catch-up with itself by growing while trying to save it. */
(mc->mc_flags & C_RECLAIMING) ||
/* avoid (recursive) search inside empty tree and while tree is
updating, https://github.com/erthink/libmdbx/issues/31 */
txn->mt_dbs[FREE_DBI].md_entries == 0 ||
/* If our dirty list is already full, we can't touch GC */
(txn->tw.dirtyroom < txn->mt_dbs[FREE_DBI].md_depth &&
!(txn->mt_dbistate[FREE_DBI] & DBI_DIRTY))))
flags &= ~(MDBX_ALLOC_GC | MDBX_COALESCE);
}
if (likely(num == 1 && (flags & MDBX_ALLOC_CACHE) != 0)) {
@ -5209,8 +5215,8 @@ skip_cache:
* Prefer pages with lower pgno. */
mdbx_tassert(txn, mdbx_pnl_check4assert(txn->tw.reclaimed_pglist,
txn->mt_next_pgno));
if (likely(flags & MDBX_ALLOC_CACHE) && re_len > wanna_range &&
(!(flags & MDBX_COALESCE) || op == MDBX_FIRST)) {
if ((flags & (MDBX_COALESCE | MDBX_ALLOC_CACHE)) == MDBX_ALLOC_CACHE &&
re_len > wanna_range) {
mdbx_tassert(txn, MDBX_PNL_LAST(re_list) < txn->mt_next_pgno &&
MDBX_PNL_FIRST(re_list) < txn->mt_next_pgno);
range_begin = MDBX_PNL_ASCENDING ? 1 : re_len;
@ -5240,11 +5246,6 @@ skip_cache:
}
if (op == MDBX_FIRST) { /* 1st iteration, setup cursor, etc */
if (unlikely(txn->tw.dirtyroom < txn->mt_dbs[FREE_DBI].md_depth) &&
!(txn->mt_dbistate[FREE_DBI] & DBI_DIRTY)) {
/* If our dirty list is already full, we can't touch GC */
flags &= ~MDBX_ALLOC_GC;
}
if (unlikely(!(flags & MDBX_ALLOC_GC)))
break /* reclaiming is prohibited for now */;
@ -5364,7 +5365,7 @@ skip_cache:
/* Stop reclaiming to avoid overflow the page list.
* This is a rare case while search for a continuously multi-page region
* in a large database. https://github.com/erthink/libmdbx/issues/123 */
flags &= ~MDBX_ALLOC_GC;
flags &= ~(MDBX_ALLOC_GC | MDBX_COALESCE);
break;
}
rc = mdbx_pnl_need(&txn->tw.reclaimed_pglist, gc_len);
@ -5397,6 +5398,7 @@ skip_cache:
rc = MDBX_CORRUPTED;
goto fail;
}
mdbx_tassert(txn, mdbx_dirtylist_check(txn));
re_len = MDBX_PNL_SIZE(re_list);
mdbx_tassert(txn, re_len == 0 || re_list[re_len] < txn->mt_next_pgno);
@ -5407,44 +5409,20 @@ skip_cache:
re_len = MDBX_PNL_SIZE(re_list);
}
if (unlikely((flags & MDBX_ALLOC_CACHE) == 0)) {
/* Done for a kick-reclaim mode, actually no page needed */
/* Done for a kick-reclaim mode, actually no page needed */
if (unlikely((flags & MDBX_ALLOC_CACHE) == 0))
return MDBX_SUCCESS;
}
/* Don't try to coalesce too much. */
if (re_len /* current size */ >= env->me_maxgc_ov1page ||
if (re_len /* current size */ > coalesce_threshold ||
(re_len > prev_re_len && re_len - prev_re_len /* delta from prev */ >=
env->me_maxgc_ov1page / 2))
coalesce_threshold / 2))
flags &= ~MDBX_COALESCE;
}
if ((flags & (MDBX_COALESCE | MDBX_ALLOC_CACHE)) == MDBX_ALLOC_CACHE &&
re_len > wanna_range) {
range_begin = MDBX_PNL_ASCENDING ? 1 : re_len;
pgno = MDBX_PNL_LEAST(re_list);
if (likely(wanna_range == 0))
goto done;
#if MDBX_PNL_ASCENDING
mdbx_tassert(txn, pgno == re_list[1] && range_begin == 1);
while (true) {
unsigned range_end = range_begin + wanna_range;
if (re_list[range_end] - pgno == wanna_range)
goto done;
if (range_end == re_len)
break;
pgno = re_list[++range_begin];
}
#else
mdbx_tassert(txn, pgno == re_list[re_len] && range_begin == re_len);
while (true) {
if (re_list[range_begin - wanna_range] - pgno == wanna_range)
goto done;
if (range_begin == wanna_range)
break;
pgno = re_list[--range_begin];
}
#endif /* MDBX_PNL sort-order */
if (F_ISSET(flags, MDBX_COALESCE | MDBX_ALLOC_CACHE)) {
flags -= MDBX_COALESCE;
continue;
}
/* There is no suitable pages in the GC and to be able to allocate
@ -5572,7 +5550,7 @@ done:
mdbx_ensure(env, pgno >= NUM_METAS);
if (env->me_flags & MDBX_WRITEMAP) {
np = pgno2page(env, pgno);
/* LY: reset no-access flag from mdbx_loose_page() */
/* LY: reset no-access flag from mdbx_page_loose() */
VALGRIND_MAKE_MEM_UNDEFINED(np, pgno2bytes(env, num));
ASAN_UNPOISON_MEMORY_REGION(np, pgno2bytes(env, num));
} else {