Fix arena_prefork lock rank order for witness.

When witness is enabled, lock rank order needs to be preserved during
prefork, not only for each arena, but also across arenas. This change
breaks arena_prefork into further stages to ensure valid rank order
across arenas. Also changed test/unit/fork to use a manual arena to
catch this case.
This commit is contained in:
Qi Wang
2017-03-08 13:00:42 -08:00
committed by Qi Wang
parent 8adab26972
commit 8721e19c04
5 changed files with 49 additions and 12 deletions

View File

@@ -1743,29 +1743,39 @@ arena_boot(void) {
void
arena_prefork0(tsdn_t *tsdn, arena_t *arena) {
malloc_mutex_prefork(tsdn, &arena->decay.mtx);
}
void
arena_prefork1(tsdn_t *tsdn, arena_t *arena) {
if (config_stats && config_tcache) {
malloc_mutex_prefork(tsdn, &arena->tcache_ql_mtx);
}
}
void
arena_prefork1(tsdn_t *tsdn, arena_t *arena) {
arena_prefork2(tsdn_t *tsdn, arena_t *arena) {
extents_prefork(tsdn, &arena->extents_cached);
extents_prefork(tsdn, &arena->extents_retained);
}
void
arena_prefork2(tsdn_t *tsdn, arena_t *arena) {
arena_prefork3(tsdn_t *tsdn, arena_t *arena) {
malloc_mutex_prefork(tsdn, &arena->extent_freelist_mtx);
}
void
arena_prefork3(tsdn_t *tsdn, arena_t *arena) {
unsigned i;
arena_prefork4(tsdn_t *tsdn, arena_t *arena) {
base_prefork(tsdn, arena->base);
}
void
arena_prefork5(tsdn_t *tsdn, arena_t *arena) {
malloc_mutex_prefork(tsdn, &arena->large_mtx);
for (i = 0; i < NBINS; i++) {
}
void
arena_prefork6(tsdn_t *tsdn, arena_t *arena) {
for (unsigned i = 0; i < NBINS; i++) {
malloc_mutex_prefork(tsdn, &arena->bins[i].lock);
}
}

View File

@@ -2773,7 +2773,8 @@ _malloc_prefork(void)
tcache_prefork(tsd_tsdn(tsd));
malloc_mutex_prefork(tsd_tsdn(tsd), &arenas_lock);
prof_prefork0(tsd_tsdn(tsd));
for (i = 0; i < 3; i++) {
/* Break arena prefork into stages to preserve lock order. */
for (i = 0; i < 7; i++) {
for (j = 0; j < narenas; j++) {
if ((arena = arena_get(tsd_tsdn(tsd), j, false)) !=
NULL) {
@@ -2787,16 +2788,23 @@ _malloc_prefork(void)
case 2:
arena_prefork2(tsd_tsdn(tsd), arena);
break;
case 3:
arena_prefork3(tsd_tsdn(tsd), arena);
break;
case 4:
arena_prefork4(tsd_tsdn(tsd), arena);
break;
case 5:
arena_prefork5(tsd_tsdn(tsd), arena);
break;
case 6:
arena_prefork6(tsd_tsdn(tsd), arena);
break;
default: not_reached();
}
}
}
}
for (i = 0; i < narenas; i++) {
if ((arena = arena_get(tsd_tsdn(tsd), i, false)) != NULL) {
arena_prefork3(tsd_tsdn(tsd), arena);
}
}
prof_prefork1(tsd_tsdn(tsd));
}