Added stats about number of bytes cached in tcache currently.

include/jemalloc/internal/stats_structs.h

@@ -100,6 +100,9 @@ struct arena_stats_s {
 	uint64_t	ndalloc_large;
 	uint64_t	nrequests_large;
 
+	/* Number of bytes cached in tcache associated with this arena. */
+	size_t		tcache_bytes;
+
 	/* One element for each large size class. */
 	malloc_large_stats_t	lstats[NSIZES - NBINS];
 };

src/arena.c

@@ -1625,6 +1625,21 @@ arena_stats_merge(tsdn_t *tsdn, arena_t *arena, unsigned *nthreads,
 		lstats[i].nrequests += arena->stats.lstats[i].nrequests;
 		lstats[i].curlextents += arena->stats.lstats[i].curlextents;
 	}
+
+	if (config_tcache) {
+		tcache_bin_t *tbin;
+		tcache_t *tcache;
+
+		/* tcache_bytes counts currently cached bytes. */
+		astats->tcache_bytes = 0;
+		ql_foreach(tcache, &arena->tcache_ql, link) {
+			for (i = 0; i < nhbins; i++) {
+				tbin = &tcache->tbins[i];
+				astats->tcache_bytes += tbin->ncached *
+				    index2size(i);
+			}
+		}
+	}
 	malloc_mutex_unlock(tsdn, &arena->lock);
 
 	for (i = 0; i < NBINS; i++) {

src/ctl.c

@@ -161,6 +161,7 @@ CTL_PROTO(stats_arenas_i_nmadvise)
 CTL_PROTO(stats_arenas_i_purged)
 CTL_PROTO(stats_arenas_i_base)
 CTL_PROTO(stats_arenas_i_internal)
+CTL_PROTO(stats_arenas_i_tcache_bytes)
 CTL_PROTO(stats_arenas_i_resident)
 INDEX_PROTO(stats_arenas_i)
 CTL_PROTO(stats_allocated)
@@ -382,6 +383,7 @@ static const ctl_named_node_t stats_arenas_i_node[] = {
 	{NAME("purged"),	CTL(stats_arenas_i_purged)},
 	{NAME("base"),		CTL(stats_arenas_i_base)},
 	{NAME("internal"),	CTL(stats_arenas_i_internal)},
+	{NAME("tcache_bytes"),	CTL(stats_arenas_i_tcache_bytes)},
 	{NAME("resident"),	CTL(stats_arenas_i_resident)},
 	{NAME("small"),		CHILD(named, stats_arenas_i_small)},
 	{NAME("large"),		CHILD(named, stats_arenas_i_large)},
@@ -601,6 +603,11 @@ ctl_arena_stats_sdmerge(ctl_arena_stats_t *sdstats, ctl_arena_stats_t *astats,
 		sdstats->astats.nrequests_large +=
 		    astats->astats.nrequests_large;
 
+		if (config_tcache) {
+			sdstats->astats.tcache_bytes +=
+			    astats->astats.tcache_bytes;
+		}
+
 		for (i = 0; i < NBINS; i++) {
 			sdstats->bstats[i].nmalloc += astats->bstats[i].nmalloc;
 			sdstats->bstats[i].ndalloc += astats->bstats[i].ndalloc;
@@ -2105,6 +2112,8 @@ CTL_RO_CGEN(config_stats, stats_arenas_i_base,
     stats_arenas_i(mib[2])->astats.base, size_t)
 CTL_RO_CGEN(config_stats, stats_arenas_i_internal,
     stats_arenas_i(mib[2])->astats.internal, size_t)
+CTL_RO_CGEN(config_stats && config_tcache, stats_arenas_i_tcache_bytes,
+    stats_arenas_i(mib[2])->astats.tcache_bytes, size_t)
 CTL_RO_CGEN(config_stats, stats_arenas_i_resident,
     stats_arenas_i(mib[2])->astats.resident, size_t)
 

src/stats.c

@@ -261,6 +261,7 @@ stats_arena_print(void (*write_cb)(void *, const char *), void *cbopaque,
 	uint64_t small_nmalloc, small_ndalloc, small_nrequests;
 	size_t large_allocated;
 	uint64_t large_nmalloc, large_ndalloc, large_nrequests;
+	size_t tcache_bytes;
 
 	CTL_GET("arenas.page", &page, size_t);
 
@@ -423,6 +424,18 @@ stats_arena_print(void (*write_cb)(void *, const char *), void *cbopaque,
 		    "internal:                %12zu\n", internal);
 	}
 
+	if (config_tcache) {
+		CTL_M2_GET("stats.arenas.0.tcache_bytes", i, &tcache_bytes,
+		    size_t);
+		if (json) {
+			malloc_cprintf(write_cb, cbopaque,
+			    "\t\t\t\t\"tcache\": %zu,\n", tcache_bytes);
+		} else {
+			malloc_cprintf(write_cb, cbopaque,
+			    "tcache:                  %12zu\n", tcache_bytes);
+		}
+	}
+
 	CTL_M2_GET("stats.arenas.0.resident", i, &resident, size_t);
 	if (json) {
 		malloc_cprintf(write_cb, cbopaque,