Optimize witness fast path.

Short-circuit commonly called witness functions so that they only
execute in debug builds, and remove equivalent guards from mutex
functions.  This avoids pointless code execution in
witness_assert_lockless(), which is typically called twice per
allocation/deallocation function invocation.

Inline commonly called witness functions so that optimized builds can
completely remove calls as dead code.
This commit is contained in:
Jason Evans 2016-05-11 15:33:28 -07:00
parent 7790a0ba40
commit 73d3d58dc2
4 changed files with 157 additions and 132 deletions

View File

@ -531,9 +531,9 @@ void jemalloc_postfork_child(void);
#include "jemalloc/internal/smoothstep.h"
#include "jemalloc/internal/stats.h"
#include "jemalloc/internal/ctl.h"
#include "jemalloc/internal/tsd.h"
#include "jemalloc/internal/witness.h"
#include "jemalloc/internal/mutex.h"
#include "jemalloc/internal/tsd.h"
#include "jemalloc/internal/mb.h"
#include "jemalloc/internal/extent.h"
#include "jemalloc/internal/base.h"

View File

@ -81,8 +81,7 @@ malloc_mutex_lock(tsdn_t *tsdn, malloc_mutex_t *mutex)
{
if (isthreaded) {
if (config_debug)
witness_assert_not_owner(tsdn, &mutex->witness);
witness_assert_not_owner(tsdn, &mutex->witness);
#ifdef _WIN32
# if _WIN32_WINNT >= 0x0600
AcquireSRWLockExclusive(&mutex->lock);
@ -94,8 +93,7 @@ malloc_mutex_lock(tsdn_t *tsdn, malloc_mutex_t *mutex)
#else
pthread_mutex_lock(&mutex->lock);
#endif
if (config_debug)
witness_lock(tsdn, &mutex->witness);
witness_lock(tsdn, &mutex->witness);
}
}
@ -104,8 +102,7 @@ malloc_mutex_unlock(tsdn_t *tsdn, malloc_mutex_t *mutex)
{
if (isthreaded) {
if (config_debug)
witness_unlock(tsdn, &mutex->witness);
witness_unlock(tsdn, &mutex->witness);
#ifdef _WIN32
# if _WIN32_WINNT >= 0x0600
ReleaseSRWLockExclusive(&mutex->lock);
@ -124,7 +121,7 @@ JEMALLOC_INLINE void
malloc_mutex_assert_owner(tsdn_t *tsdn, malloc_mutex_t *mutex)
{
if (isthreaded && config_debug)
if (isthreaded)
witness_assert_owner(tsdn, &mutex->witness);
}
@ -132,7 +129,7 @@ JEMALLOC_INLINE void
malloc_mutex_assert_not_owner(tsdn_t *tsdn, malloc_mutex_t *mutex)
{
if (isthreaded && config_debug)
if (isthreaded)
witness_assert_not_owner(tsdn, &mutex->witness);
}
#endif

View File

@ -74,24 +74,28 @@ void witness_init(witness_t *witness, const char *name, witness_rank_t rank,
#ifdef JEMALLOC_JET
typedef void (witness_lock_error_t)(const witness_list_t *, const witness_t *);
extern witness_lock_error_t *witness_lock_error;
#else
void witness_lock_error(const witness_list_t *witnesses,
const witness_t *witness);
#endif
void witness_lock(tsdn_t *tsdn, witness_t *witness);
void witness_unlock(tsdn_t *tsdn, witness_t *witness);
#ifdef JEMALLOC_JET
typedef void (witness_owner_error_t)(const witness_t *);
extern witness_owner_error_t *witness_owner_error;
#else
void witness_owner_error(const witness_t *witness);
#endif
void witness_assert_owner(tsdn_t *tsdn, const witness_t *witness);
#ifdef JEMALLOC_JET
typedef void (witness_not_owner_error_t)(const witness_t *);
extern witness_not_owner_error_t *witness_not_owner_error;
#else
void witness_not_owner_error(const witness_t *witness);
#endif
void witness_assert_not_owner(tsdn_t *tsdn, const witness_t *witness);
#ifdef JEMALLOC_JET
typedef void (witness_lockless_error_t)(const witness_list_t *);
extern witness_lockless_error_t *witness_lockless_error;
#else
void witness_lockless_error(const witness_list_t *witnesses);
#endif
void witness_assert_lockless(tsdn_t *tsdn);
void witnesses_cleanup(tsd_t *tsd);
void witness_fork_cleanup(tsd_t *tsd);
@ -103,5 +107,143 @@ void witness_postfork_child(tsd_t *tsd);
/******************************************************************************/
#ifdef JEMALLOC_H_INLINES
#ifndef JEMALLOC_ENABLE_INLINE
void witness_assert_owner(tsdn_t *tsdn, const witness_t *witness);
void witness_assert_not_owner(tsdn_t *tsdn, const witness_t *witness);
void witness_assert_lockless(tsdn_t *tsdn);
void witness_lock(tsdn_t *tsdn, witness_t *witness);
void witness_unlock(tsdn_t *tsdn, witness_t *witness);
#endif
#if (defined(JEMALLOC_ENABLE_INLINE) || defined(JEMALLOC_MUTEX_C_))
JEMALLOC_INLINE void
witness_assert_owner(tsdn_t *tsdn, const witness_t *witness)
{
tsd_t *tsd;
witness_list_t *witnesses;
witness_t *w;
if (!config_debug)
return;
if (tsdn_null(tsdn))
return;
tsd = tsdn_tsd(tsdn);
if (witness->rank == WITNESS_RANK_OMIT)
return;
witnesses = tsd_witnessesp_get(tsd);
ql_foreach(w, witnesses, link) {
if (w == witness)
return;
}
witness_owner_error(witness);
}
JEMALLOC_INLINE void
witness_assert_not_owner(tsdn_t *tsdn, const witness_t *witness)
{
tsd_t *tsd;
witness_list_t *witnesses;
witness_t *w;
if (!config_debug)
return;
if (tsdn_null(tsdn))
return;
tsd = tsdn_tsd(tsdn);
if (witness->rank == WITNESS_RANK_OMIT)
return;
witnesses = tsd_witnessesp_get(tsd);
ql_foreach(w, witnesses, link) {
if (w == witness)
witness_not_owner_error(witness);
}
}
JEMALLOC_INLINE void
witness_assert_lockless(tsdn_t *tsdn)
{
tsd_t *tsd;
witness_list_t *witnesses;
witness_t *w;
if (!config_debug)
return;
if (tsdn_null(tsdn))
return;
tsd = tsdn_tsd(tsdn);
witnesses = tsd_witnessesp_get(tsd);
w = ql_last(witnesses, link);
if (w != NULL)
witness_lockless_error(witnesses);
}
JEMALLOC_INLINE void
witness_lock(tsdn_t *tsdn, witness_t *witness)
{
tsd_t *tsd;
witness_list_t *witnesses;
witness_t *w;
if (!config_debug)
return;
if (tsdn_null(tsdn))
return;
tsd = tsdn_tsd(tsdn);
if (witness->rank == WITNESS_RANK_OMIT)
return;
witness_assert_not_owner(tsdn, witness);
witnesses = tsd_witnessesp_get(tsd);
w = ql_last(witnesses, link);
if (w == NULL) {
/* No other locks; do nothing. */
} else if (tsd_witness_fork_get(tsd) && w->rank <= witness->rank) {
/* Forking, and relaxed ranking satisfied. */
} else if (w->rank > witness->rank) {
/* Not forking, rank order reversal. */
witness_lock_error(witnesses, witness);
} else if (w->rank == witness->rank && (w->comp == NULL || w->comp !=
witness->comp || w->comp(w, witness) > 0)) {
/*
* Missing/incompatible comparison function, or comparison
* function indicates rank order reversal.
*/
witness_lock_error(witnesses, witness);
}
ql_elm_new(witness, link);
ql_tail_insert(witnesses, witness, link);
}
JEMALLOC_INLINE void
witness_unlock(tsdn_t *tsdn, witness_t *witness)
{
tsd_t *tsd;
witness_list_t *witnesses;
if (!config_debug)
return;
if (tsdn_null(tsdn))
return;
tsd = tsdn_tsd(tsdn);
if (witness->rank == WITNESS_RANK_OMIT)
return;
witness_assert_owner(tsdn, witness);
witnesses = tsd_witnessesp_get(tsd);
ql_remove(witnesses, witness, link);
}
#endif
#endif /* JEMALLOC_H_INLINES */
/******************************************************************************/

View File

@ -15,7 +15,7 @@ witness_init(witness_t *witness, const char *name, witness_rank_t rank,
#undef witness_lock_error
#define witness_lock_error JEMALLOC_N(witness_lock_error_impl)
#endif
static void
void
witness_lock_error(const witness_list_t *witnesses, const witness_t *witness)
{
witness_t *w;
@ -33,66 +33,11 @@ witness_lock_error(const witness_list_t *witnesses, const witness_t *witness)
witness_lock_error_t *witness_lock_error = JEMALLOC_N(witness_lock_error_impl);
#endif
void
witness_lock(tsdn_t *tsdn, witness_t *witness)
{
tsd_t *tsd;
witness_list_t *witnesses;
witness_t *w;
if (tsdn_null(tsdn))
return;
tsd = tsdn_tsd(tsdn);
if (witness->rank == WITNESS_RANK_OMIT)
return;
witness_assert_not_owner(tsdn, witness);
witnesses = tsd_witnessesp_get(tsd);
w = ql_last(witnesses, link);
if (w == NULL) {
/* No other locks; do nothing. */
} else if (tsd_witness_fork_get(tsd) && w->rank <= witness->rank) {
/* Forking, and relaxed ranking satisfied. */
} else if (w->rank > witness->rank) {
/* Not forking, rank order reversal. */
witness_lock_error(witnesses, witness);
} else if (w->rank == witness->rank && (w->comp == NULL || w->comp !=
witness->comp || w->comp(w, witness) > 0)) {
/*
* Missing/incompatible comparison function, or comparison
* function indicates rank order reversal.
*/
witness_lock_error(witnesses, witness);
}
ql_elm_new(witness, link);
ql_tail_insert(witnesses, witness, link);
}
void
witness_unlock(tsdn_t *tsdn, witness_t *witness)
{
tsd_t *tsd;
witness_list_t *witnesses;
if (tsdn_null(tsdn))
return;
tsd = tsdn_tsd(tsdn);
if (witness->rank == WITNESS_RANK_OMIT)
return;
witness_assert_owner(tsdn, witness);
witnesses = tsd_witnessesp_get(tsd);
ql_remove(witnesses, witness, link);
}
#ifdef JEMALLOC_JET
#undef witness_owner_error
#define witness_owner_error JEMALLOC_N(witness_owner_error_impl)
#endif
static void
void
witness_owner_error(const witness_t *witness)
{
@ -107,32 +52,11 @@ witness_owner_error_t *witness_owner_error =
JEMALLOC_N(witness_owner_error_impl);
#endif
void
witness_assert_owner(tsdn_t *tsdn, const witness_t *witness)
{
tsd_t *tsd;
witness_list_t *witnesses;
witness_t *w;
if (tsdn_null(tsdn))
return;
tsd = tsdn_tsd(tsdn);
if (witness->rank == WITNESS_RANK_OMIT)
return;
witnesses = tsd_witnessesp_get(tsd);
ql_foreach(w, witnesses, link) {
if (w == witness)
return;
}
witness_owner_error(witness);
}
#ifdef JEMALLOC_JET
#undef witness_not_owner_error
#define witness_not_owner_error JEMALLOC_N(witness_not_owner_error_impl)
#endif
static void
void
witness_not_owner_error(const witness_t *witness)
{
@ -147,31 +71,11 @@ witness_not_owner_error_t *witness_not_owner_error =
JEMALLOC_N(witness_not_owner_error_impl);
#endif
void
witness_assert_not_owner(tsdn_t *tsdn, const witness_t *witness)
{
tsd_t *tsd;
witness_list_t *witnesses;
witness_t *w;
if (tsdn_null(tsdn))
return;
tsd = tsdn_tsd(tsdn);
if (witness->rank == WITNESS_RANK_OMIT)
return;
witnesses = tsd_witnessesp_get(tsd);
ql_foreach(w, witnesses, link) {
if (w == witness)
witness_not_owner_error(witness);
}
}
#ifdef JEMALLOC_JET
#undef witness_lockless_error
#define witness_lockless_error JEMALLOC_N(witness_lockless_error_impl)
#endif
static void
void
witness_lockless_error(const witness_list_t *witnesses)
{
witness_t *w;
@ -190,24 +94,6 @@ witness_lockless_error_t *witness_lockless_error =
JEMALLOC_N(witness_lockless_error_impl);
#endif
void
witness_assert_lockless(tsdn_t *tsdn)
{
tsd_t *tsd;
witness_list_t *witnesses;
witness_t *w;
if (tsdn_null(tsdn))
return;
tsd = tsdn_tsd(tsdn);
witnesses = tsd_witnessesp_get(tsd);
w = ql_last(witnesses, link);
if (w != NULL) {
witness_lockless_error(witnesses);
}
}
void
witnesses_cleanup(tsd_t *tsd)
{