Skip to content

Commit

Permalink
MDEV-15059 - Misc small InnoDB scalability fixes
Browse files Browse the repository at this point in the history 
Moved mutex locking inside lock_rec_lock().
Moved monitor increment out of mutex.
Moved assertions that don't require protection out of mutex.
Removed duplicate assertions.
Moved duplicate debug injections into lock_rec_lock().
Let monitor updates use relaxed memory order.
Return directly without maintaining variables in lock_rec_lock_slow().
Moved lock_rec_lock_fast() body into lock_rec_lock(): saves at least one
trx_mutex_enter(), one switch() plus some code was moved out of mutex.
  • Loading branch information
Sergey Vojtovich committed Jan 26, 2018
1 parent ce04790 commit 8389b45
Show file tree
Hide file tree
Showing 3 changed files with 71 additions and 187 deletions.
4 changes: 2 additions & 2 deletions storage/innobase/include/lock0priv.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -745,7 +745,7 @@ class RecLock {
#ifdef WITH_WSREP
,lock_t* c_lock = NULL
#endif /* WITH_WSREP */
);
) const;

/**
Check of the lock is on m_rec_id.
Expand Down Expand Up @@ -838,7 +838,7 @@ class RecLock {
@param[in,out] lock Newly created record lock to add to the
rec hash and the transaction lock list
@param[in] add_to_hash If the lock should be added to the hash table */
void lock_add(lock_t* lock, bool add_to_hash);
void lock_add(lock_t* lock, bool add_to_hash) const;

/**
Check and resolve any deadlocks
Expand Down
10 changes: 6 additions & 4 deletions storage/innobase/include/srv0mon.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -608,8 +608,9 @@ Use MONITOR_INC if appropriate mutex protection exists.
#define MONITOR_ATOMIC_INC_LOW(monitor, enabled) \
if (enabled) { \
ib_uint64_t value; \
value = my_atomic_add64( \
(int64*) &MONITOR_VALUE(monitor), 1) + 1; \
value = my_atomic_add64_explicit( \
(int64*) &MONITOR_VALUE(monitor), 1, \
MY_MEMORY_ORDER_RELAXED) + 1; \
/* Note: This is not 100% accurate because of the \
inherent race, we ignore it due to performance. */ \
if (value > (ib_uint64_t) MONITOR_MAX_VALUE(monitor)) { \
Expand All @@ -624,8 +625,9 @@ Use MONITOR_DEC if appropriate mutex protection exists.
#define MONITOR_ATOMIC_DEC_LOW(monitor, enabled) \
if (enabled) { \
ib_uint64_t value; \
value = my_atomic_add64( \
(int64*) &MONITOR_VALUE(monitor), -1) - 1; \
value = my_atomic_add64_explicit( \
(int64*) &MONITOR_VALUE(monitor), -1, \
MY_MEMORY_ORDER_RELAXED) - 1; \
/* Note: This is not 100% accurate because of the \
inherent race, we ignore it due to performance. */ \
if (value < (ib_uint64_t) MONITOR_MIN_VALUE(monitor)) { \
Expand Down
244 changes: 63 additions & 181 deletions storage/innobase/lock/lock0lock.cc
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1877,7 +1877,7 @@ Add the lock to the record lock hash and the transaction's lock list
@param[in,out] lock Newly created record lock to add to the rec hash
@param[in] add_to_hash If the lock should be added to the hash table */
void
RecLock::lock_add(lock_t* lock, bool add_to_hash)
RecLock::lock_add(lock_t* lock, bool add_to_hash) const
{
ut_ad(lock_mutex_own());
ut_ad(trx_mutex_own(lock->trx));
Expand Down Expand Up @@ -1929,7 +1929,7 @@ RecLock::create(
#ifdef WITH_WSREP
,lock_t* c_lock
#endif /* WITH_WSREP */
)
) const
{
ut_ad(lock_mutex_own());
ut_ad(owns_trx_mutex == trx_mutex_own(trx));
Expand Down Expand Up @@ -2389,88 +2389,6 @@ lock_rec_add_to_queue(
rec_lock.create(trx, caller_owns_trx_mutex, true);
}

/*********************************************************************//**
This is a fast routine for locking a record in the most common cases:
there are no explicit locks on the page, or there is just one lock, owned
by this transaction, and of the right type_mode. This is a low-level function
which does NOT look at implicit locks! Checks lock compatibility within
explicit locks. This function sets a normal next-key lock, or in the case of
a page supremum record, a gap type lock.
@return whether the locking succeeded */
UNIV_INLINE
lock_rec_req_status
lock_rec_lock_fast(
/*===============*/
bool impl, /*!< in: if TRUE, no lock is set
if no wait is necessary: we
assume that the caller will
set an implicit lock */
ulint mode, /*!< in: lock mode: LOCK_X or
LOCK_S possibly ORed to either
LOCK_GAP or LOCK_REC_NOT_GAP */
const buf_block_t* block, /*!< in: buffer block containing
the record */
ulint heap_no,/*!< in: heap number of record */
dict_index_t* index, /*!< in: index of record */
que_thr_t* thr) /*!< in: query thread */
{
ut_ad(lock_mutex_own());
ut_ad(!srv_read_only_mode);
ut_ad((LOCK_MODE_MASK & mode) != LOCK_S
|| lock_table_has(thr_get_trx(thr), index->table, LOCK_IS));
ut_ad((LOCK_MODE_MASK & mode) != LOCK_X
|| lock_table_has(thr_get_trx(thr), index->table, LOCK_IX)
|| srv_read_only_mode);
ut_ad((LOCK_MODE_MASK & mode) == LOCK_S
|| (LOCK_MODE_MASK & mode) == LOCK_X);
ut_ad(mode - (LOCK_MODE_MASK & mode) == LOCK_GAP
|| mode - (LOCK_MODE_MASK & mode) == 0
|| mode - (LOCK_MODE_MASK & mode) == LOCK_REC_NOT_GAP);
ut_ad(dict_index_is_clust(index) || !dict_index_is_online_ddl(index));

DBUG_EXECUTE_IF("innodb_report_deadlock", return(LOCK_REC_FAIL););

lock_t* lock = lock_rec_get_first_on_page(lock_sys->rec_hash, block);

trx_t* trx = thr_get_trx(thr);

lock_rec_req_status status = LOCK_REC_SUCCESS;

if (lock == NULL) {

if (!impl) {
RecLock rec_lock(index, block, heap_no, mode);

/* Note that we don't own the trx mutex. */
rec_lock.create(trx, false, true);
}

status = LOCK_REC_SUCCESS_CREATED;
} else {
trx_mutex_enter(trx);

if (lock_rec_get_next_on_page(lock)
|| lock->trx != trx
|| lock->type_mode != (mode | LOCK_REC)
|| lock_rec_get_n_bits(lock) <= heap_no) {

status = LOCK_REC_FAIL;
} else if (!impl) {
/* If the nth bit of the record lock is already set
then we do not set a new lock bit, otherwise we do
set */
if (!lock_rec_get_nth_bit(lock, heap_no)) {
lock_rec_set_nth_bit(lock, heap_no);
status = LOCK_REC_SUCCESS_CREATED;
}
}

trx_mutex_exit(trx);
}

return(status);
}

/*********************************************************************//**
This is the general, and slower, routine for locking a record. This is a
low-level function which does NOT look at implicit locks! Checks lock
Expand All @@ -2496,33 +2414,12 @@ lock_rec_lock_slow(
que_thr_t* thr) /*!< in: query thread */
{
ut_ad(lock_mutex_own());
ut_ad(!srv_read_only_mode);
ut_ad((LOCK_MODE_MASK & mode) != LOCK_S
|| lock_table_has(thr_get_trx(thr), index->table, LOCK_IS));
ut_ad((LOCK_MODE_MASK & mode) != LOCK_X
|| lock_table_has(thr_get_trx(thr), index->table, LOCK_IX));
ut_ad((LOCK_MODE_MASK & mode) == LOCK_S
|| (LOCK_MODE_MASK & mode) == LOCK_X);
ut_ad(mode - (LOCK_MODE_MASK & mode) == LOCK_GAP
|| mode - (LOCK_MODE_MASK & mode) == 0
|| mode - (LOCK_MODE_MASK & mode) == LOCK_REC_NOT_GAP);
ut_ad(dict_index_is_clust(index) || !dict_index_is_online_ddl(index));

DBUG_EXECUTE_IF("innodb_report_deadlock", return(DB_DEADLOCK););

dberr_t err;
trx_t* trx = thr_get_trx(thr);
ut_ad(trx_mutex_own(trx));

trx_mutex_enter(trx);

if (lock_rec_has_expl(mode, block, heap_no, trx)) {

/* The trx already has a strong enough lock on rec: do
nothing */

err = DB_SUCCESS;

} else {
/* Do nothing if the trx already has a strong enough lock on rec */
if (!lock_rec_has_expl(mode, block, heap_no, trx)) {
lock_t* wait_for = lock_rec_other_has_conflicting(
mode, block, heap_no, trx);

Expand All @@ -2535,7 +2432,7 @@ lock_rec_lock_slow(

RecLock rec_lock(thr, index, block, heap_no, mode);

err = rec_lock.add_to_waitq(wait_for);
return rec_lock.add_to_waitq(wait_for);

} else if (!impl) {

Expand All @@ -2546,15 +2443,10 @@ lock_rec_lock_slow(
LOCK_REC | mode, block, heap_no, index, trx,
true);

err = DB_SUCCESS_LOCKED_REC;
} else {
err = DB_SUCCESS;
return DB_SUCCESS_LOCKED_REC;
}
}

trx_mutex_exit(trx);

return(err);
return DB_SUCCESS;
}

/*********************************************************************//**
Expand Down Expand Up @@ -2582,33 +2474,61 @@ lock_rec_lock(
dict_index_t* index, /*!< in: index of record */
que_thr_t* thr) /*!< in: query thread */
{
ut_ad(lock_mutex_own());
ut_ad(!srv_read_only_mode);
ut_ad((LOCK_MODE_MASK & mode) != LOCK_S
|| lock_table_has(thr_get_trx(thr), index->table, LOCK_IS));
ut_ad((LOCK_MODE_MASK & mode) != LOCK_X
|| lock_table_has(thr_get_trx(thr), index->table, LOCK_IX));
ut_ad((LOCK_MODE_MASK & mode) == LOCK_S
|| (LOCK_MODE_MASK & mode) == LOCK_X);
ut_ad(mode - (LOCK_MODE_MASK & mode) == LOCK_GAP
|| mode - (LOCK_MODE_MASK & mode) == LOCK_REC_NOT_GAP
|| mode - (LOCK_MODE_MASK & mode) == 0);
ut_ad(dict_index_is_clust(index) || !dict_index_is_online_ddl(index));

/* We try a simplified and faster subroutine for the most
common cases */
switch (lock_rec_lock_fast(impl, mode, block, heap_no, index, thr)) {
case LOCK_REC_SUCCESS:
return(DB_SUCCESS);
case LOCK_REC_SUCCESS_CREATED:
return(DB_SUCCESS_LOCKED_REC);
case LOCK_REC_FAIL:
return(lock_rec_lock_slow(impl, mode, block,
heap_no, index, thr));
}

ut_error;
return(DB_ERROR);
trx_t *trx= thr_get_trx(thr);
dberr_t err= DB_SUCCESS;

ut_ad(!srv_read_only_mode);
ut_ad((LOCK_MODE_MASK & mode) == LOCK_S ||
(LOCK_MODE_MASK & mode) == LOCK_X);
ut_ad((mode & LOCK_TYPE_MASK) == LOCK_GAP ||
(mode & LOCK_TYPE_MASK) == LOCK_REC_NOT_GAP ||
(mode & LOCK_TYPE_MASK) == 0);
ut_ad(dict_index_is_clust(index) || !dict_index_is_online_ddl(index));
DBUG_EXECUTE_IF("innodb_report_deadlock", return DB_DEADLOCK;);

lock_mutex_enter();
ut_ad((LOCK_MODE_MASK & mode) != LOCK_S ||
lock_table_has(trx, index->table, LOCK_IS));
ut_ad((LOCK_MODE_MASK & mode) != LOCK_X ||
lock_table_has(trx, index->table, LOCK_IX));

if (lock_t *lock= lock_rec_get_first_on_page(lock_sys->rec_hash, block))
{
trx_mutex_enter(trx);
if (lock_rec_get_next_on_page(lock) ||
lock->trx != trx ||
lock->type_mode != (mode | LOCK_REC) ||
lock_rec_get_n_bits(lock) <= heap_no)
{
err= lock_rec_lock_slow(impl, mode, block, heap_no, index, thr);
}
else if (!impl)
{
/*
If the nth bit of the record lock is already set then we do not set
a new lock bit, otherwise we do set
*/
if (!lock_rec_get_nth_bit(lock, heap_no))
{
lock_rec_set_nth_bit(lock, heap_no);
err= DB_SUCCESS_LOCKED_REC;
}
}
trx_mutex_exit(trx);
}
else
{
/*
Simplified and faster path for the most common cases
Note that we don't own the trx mutex.
*/
if (!impl)
RecLock(index, block, heap_no, mode).create(trx, false, true);
err= DB_SUCCESS_LOCKED_REC;
}
lock_mutex_exit();
MONITOR_ATOMIC_INC(MONITOR_NUM_RECLOCK_REQ);
return err;
}

/*********************************************************************//**
Expand Down Expand Up @@ -6575,17 +6495,9 @@ lock_clust_rec_modify_check_and_lock(
lock_rec_convert_impl_to_expl(thr_get_trx(thr), block, rec, index,
offsets);

lock_mutex_enter();

ut_ad(lock_table_has(thr_get_trx(thr), index->table, LOCK_IX));

err = lock_rec_lock(TRUE, LOCK_X | LOCK_REC_NOT_GAP,
block, heap_no, index, thr);

MONITOR_INC(MONITOR_NUM_RECLOCK_REQ);

lock_mutex_exit();

ut_ad(lock_rec_queue_validate(FALSE, block, rec, index, offsets));

if (err == DB_SUCCESS_LOCKED_REC) {
Expand Down Expand Up @@ -6638,17 +6550,9 @@ lock_sec_rec_modify_check_and_lock(
index record, and this would not have been possible if another active
transaction had modified this secondary index record. */

lock_mutex_enter();

ut_ad(lock_table_has(thr_get_trx(thr), index->table, LOCK_IX));

err = lock_rec_lock(TRUE, LOCK_X | LOCK_REC_NOT_GAP,
block, heap_no, index, thr);

MONITOR_INC(MONITOR_NUM_RECLOCK_REQ);

lock_mutex_exit();

#ifdef UNIV_DEBUG
{
mem_heap_t* heap = NULL;
Expand Down Expand Up @@ -6740,20 +6644,9 @@ lock_sec_rec_read_check_and_lock(
index, offsets);
}

lock_mutex_enter();

ut_ad(mode != LOCK_X
|| lock_table_has(thr_get_trx(thr), index->table, LOCK_IX));
ut_ad(mode != LOCK_S
|| lock_table_has(thr_get_trx(thr), index->table, LOCK_IS));

err = lock_rec_lock(FALSE, mode | gap_mode,
block, heap_no, index, thr);

MONITOR_INC(MONITOR_NUM_RECLOCK_REQ);

lock_mutex_exit();

ut_ad(lock_rec_queue_validate(FALSE, block, rec, index, offsets));

return(err);
Expand Down Expand Up @@ -6816,19 +6709,8 @@ lock_clust_rec_read_check_and_lock(
index, offsets);
}

lock_mutex_enter();

ut_ad(mode != LOCK_X
|| lock_table_has(thr_get_trx(thr), index->table, LOCK_IX));
ut_ad(mode != LOCK_S
|| lock_table_has(thr_get_trx(thr), index->table, LOCK_IS));

err = lock_rec_lock(FALSE, mode | gap_mode, block, heap_no, index, thr);

MONITOR_INC(MONITOR_NUM_RECLOCK_REQ);

lock_mutex_exit();

ut_ad(lock_rec_queue_validate(FALSE, block, rec, index, offsets));

DEBUG_SYNC_C("after_lock_clust_rec_read_check_and_lock");
Expand Down

0 comments on commit 8389b45

Please sign in to comment.