diff --git a/doc/jemalloc.xml.in b/doc/jemalloc.xml.in
index 3ec43ce1..1e12fd3a 100644
--- a/doc/jemalloc.xml.in
+++ b/doc/jemalloc.xml.in
@@ -2130,6 +2130,15 @@ struct extent_hooks_s {
and return the new arena index.
+
+
+ arenas.lookup
+ (unsigned, void*)
+ rw
+
+ Index of the arena to which an allocation belongs to.
+
+
prof.thread_active_init
diff --git a/src/ctl.c b/src/ctl.c
index 86c2837a..1e713a3d 100644
--- a/src/ctl.c
+++ b/src/ctl.c
@@ -139,6 +139,7 @@ CTL_PROTO(arenas_nbins)
CTL_PROTO(arenas_nhbins)
CTL_PROTO(arenas_nlextents)
CTL_PROTO(arenas_create)
+CTL_PROTO(arenas_lookup)
CTL_PROTO(prof_thread_active_init)
CTL_PROTO(prof_active)
CTL_PROTO(prof_dump)
@@ -373,7 +374,8 @@ static const ctl_named_node_t arenas_node[] = {
{NAME("bin"), CHILD(indexed, arenas_bin)},
{NAME("nlextents"), CTL(arenas_nlextents)},
{NAME("lextent"), CHILD(indexed, arenas_lextent)},
- {NAME("create"), CTL(arenas_create)}
+ {NAME("create"), CTL(arenas_create)},
+ {NAME("lookup"), CTL(arenas_lookup)}
};
static const ctl_named_node_t prof_node[] = {
@@ -2471,6 +2473,36 @@ label_return:
return ret;
}
+static int
+arenas_lookup_ctl(tsd_t *tsd, const size_t *mib, size_t miblen, void *oldp,
+ size_t *oldlenp, void *newp, size_t newlen) {
+ int ret;
+ unsigned arena_ind;
+ void *ptr;
+ extent_t *extent;
+ arena_t *arena;
+
+ ptr = NULL;
+ ret = EINVAL;
+ malloc_mutex_lock(tsd_tsdn(tsd), &ctl_mtx);
+ WRITE(ptr, void *);
+ extent = iealloc(tsd_tsdn(tsd), ptr);
+ if (extent == NULL)
+ goto label_return;
+
+ arena = extent_arena_get(extent);
+ if (arena == NULL)
+ goto label_return;
+
+ arena_ind = arena_ind_get(arena);
+ READ(arena_ind, unsigned);
+
+ ret = 0;
+label_return:
+ malloc_mutex_unlock(tsd_tsdn(tsd), &ctl_mtx);
+ return ret;
+}
+
/******************************************************************************/
static int
diff --git a/test/unit/mallctl.c b/test/unit/mallctl.c
index f8b180b1..1ecbab08 100644
--- a/test/unit/mallctl.c
+++ b/test/unit/mallctl.c
@@ -738,6 +738,22 @@ TEST_BEGIN(test_arenas_create) {
}
TEST_END
+TEST_BEGIN(test_arenas_lookup) {
+ unsigned arena, arena1;
+ void *ptr;
+ size_t sz = sizeof(unsigned);
+
+ assert_d_eq(mallctl("arenas.create", (void *)&arena, &sz, NULL, 0), 0,
+ "Unexpected mallctl() failure");
+ ptr = mallocx(42, MALLOCX_ARENA(arena) | MALLOCX_TCACHE_NONE);
+ assert_ptr_not_null(ptr, "Unexpected mallocx() failure");
+ assert_d_eq(mallctl("arenas.lookup", &arena1, &sz, &ptr, sizeof(ptr)),
+ 0, "Unexpected mallctl() failure");
+ assert_u_eq(arena, arena1, "Unexpected arena index");
+ dallocx(ptr, 0);
+}
+TEST_END
+
TEST_BEGIN(test_stats_arenas) {
#define TEST_STATS_ARENAS(t, name) do { \
t name; \
@@ -784,5 +800,6 @@ main(void) {
test_arenas_bin_constants,
test_arenas_lextent_constants,
test_arenas_create,
+ test_arenas_lookup,
test_stats_arenas);
}