High Resolution Timestamps for Profiling

src/ctl.c

@@ -129,6 +129,7 @@ CTL_PROTO(opt_prof_leak)
 CTL_PROTO(opt_prof_accum)
 CTL_PROTO(opt_prof_recent_alloc_max)
 CTL_PROTO(opt_prof_experimental_use_sys_thread_name)
+CTL_PROTO(opt_prof_time_res)
 CTL_PROTO(opt_zero_realloc)
 CTL_PROTO(tcache_create)
 CTL_PROTO(tcache_flush)
@@ -385,7 +386,8 @@ static const ctl_named_node_t opt_node[] = {
 	{NAME("prof_recent_alloc_max"), CTL(opt_prof_recent_alloc_max)},
 	{NAME("prof_experimental_use_sys_thread_name"),
 	    CTL(opt_prof_experimental_use_sys_thread_name)},
-	{NAME("zero_realloc"),	CTL(opt_zero_realloc)}
+	{NAME("zero_realloc"),	CTL(opt_zero_realloc)},
+	{NAME("prof_time_resolution"),	CTL(opt_prof_time_res)}
 };
 
 static const ctl_named_node_t	tcache_node[] = {
@@ -1853,6 +1855,8 @@ CTL_RO_NL_CGEN(config_prof, opt_prof_recent_alloc_max,
     opt_prof_recent_alloc_max, ssize_t)
 CTL_RO_NL_CGEN(config_prof, opt_prof_experimental_use_sys_thread_name,
     opt_prof_experimental_use_sys_thread_name, bool)
+CTL_RO_NL_CGEN(config_prof, opt_prof_time_res,
+    prof_time_res_mode_names[opt_prof_time_res], const char *)
 CTL_RO_NL_GEN(opt_zero_realloc,
     zero_realloc_mode_names[opt_zero_realloc_action], const char *)
 

src/jemalloc.c

@@ -14,6 +14,7 @@
 #include "jemalloc/internal/log.h"
 #include "jemalloc/internal/malloc_io.h"
 #include "jemalloc/internal/mutex.h"
+#include "jemalloc/internal/nstime.h"
 #include "jemalloc/internal/rtree.h"
 #include "jemalloc/internal/safety_check.h"
 #include "jemalloc/internal/sc.h"
@@ -1497,6 +1498,26 @@ malloc_conf_init_helper(sc_data_t *sc_data, unsigned bin_shard_sizes[SC_NBINS],
 				CONF_HANDLE_BOOL(
 				    opt_prof_experimental_use_sys_thread_name,
 				    "prof_experimental_use_sys_thread_name")
+				if (CONF_MATCH("prof_time_resolution")) {
+					if (CONF_MATCH_VALUE("default")) {
+						opt_prof_time_res =
+						    prof_time_res_default;
+					} else if (CONF_MATCH_VALUE("high")) {
+						if (!config_high_res_timer) {
+							CONF_ERROR(
+							    "No high resolution"
+							    " timer support",
+							    k, klen, v, vlen);
+						} else {
+							opt_prof_time_res =
+							    prof_time_res_high;
+						}
+					} else {
+						CONF_ERROR("Invalid conf value",
+						    k, klen, v, vlen);
+					}
+				}
+				CONF_CONTINUE;
 			}
 			if (config_log) {
 				if (CONF_MATCH("log")) {

src/large.c

@@ -305,7 +305,7 @@ large_prof_tctx_reset(edata_t *edata) {
 void
 large_prof_info_set(edata_t *edata, prof_tctx_t *tctx) {
 	nstime_t t;
-	nstime_init_update(&t);
+	nstime_prof_init_update(&t);
 	edata_prof_alloc_time_set(edata, &t);
 	edata_prof_recent_alloc_init(edata);
 	large_prof_tctx_set(edata, tctx);

src/nstime.c

@@ -152,25 +152,65 @@ nstime_monotonic_impl(void) {
 }
 nstime_monotonic_t *JET_MUTABLE nstime_monotonic = nstime_monotonic_impl;
 
-static bool
+prof_time_res_t opt_prof_time_res =
+	prof_time_res_default;
+
+const char *prof_time_res_mode_names[] = {
+	"default",
+	"high",
+};
+
+
+static void
+nstime_get_realtime(nstime_t *time) {
+#if defined(JEMALLOC_HAVE_CLOCK_REALTIME) && !defined(_WIN32)
+	struct timespec ts;
+
+	clock_gettime(CLOCK_REALTIME, &ts);
+	nstime_init2(time, ts.tv_sec, ts.tv_nsec);
+#else
+	unreachable();
+#endif
+}
+
+static void
+nstime_prof_update_impl(nstime_t *time) {
+	nstime_t old_time;
+
+	nstime_copy(&old_time, time);
+
+	if (opt_prof_time_res == prof_time_res_high) {
+		nstime_get_realtime(time);
+	} else {
+		nstime_get(time);
+	}
+}
+nstime_prof_update_t *JET_MUTABLE nstime_prof_update = nstime_prof_update_impl;
+
+static void
 nstime_update_impl(nstime_t *time) {
 	nstime_t old_time;
 
 	nstime_copy(&old_time, time);
-	nstime_get(time);
+  nstime_get(time);
 
 	/* Handle non-monotonic clocks. */
 	if (unlikely(nstime_compare(&old_time, time) > 0)) {
 		nstime_copy(time, &old_time);
-		return true;
 	}
-
-	return false;
 }
 nstime_update_t *JET_MUTABLE nstime_update = nstime_update_impl;
 
-bool
+void
 nstime_init_update(nstime_t *time) {
 	nstime_init_zero(time);
-	return nstime_update(time);
+	nstime_update(time);
 }
+
+void
+nstime_prof_init_update(nstime_t *time) {
+	nstime_init_zero(time);
+	nstime_prof_update(time);
+}
+
+

src/prof_log.c

@@ -235,7 +235,7 @@ prof_try_log(tsd_t *tsd, size_t usize, prof_info_t *prof_info) {
 
 	nstime_t alloc_time = prof_info->alloc_time;
 	nstime_t free_time;
-	nstime_init_update(&free_time);
+	nstime_prof_init_update(&free_time);
 
 	size_t sz = sizeof(prof_alloc_node_t);
 	prof_alloc_node_t *new_node = (prof_alloc_node_t *)
@@ -572,6 +572,11 @@ prof_log_emit_metadata(emitter_t *emitter) {
 	emitter_json_kv(emitter, "lg_sample_rate",
 	    emitter_type_int, &lg_prof_sample);
 
+  const char *res_type =
+    prof_time_res_mode_names[opt_prof_time_res];
+  emitter_json_kv(emitter, "prof_time_resolution",
+      emitter_type_string, &res_type);
+
 	int pid = prof_getpid();
 	emitter_json_kv(emitter, "pid", emitter_type_int, &pid);
 

src/prof_recent.c

@@ -219,7 +219,7 @@ prof_recent_alloc_reset(tsd_t *tsd, edata_t *edata) {
 		assert(nstime_equals_zero(&recent->dalloc_time));
 		assert(recent->dalloc_tctx == NULL);
 		if (dalloc_tctx != NULL) {
-			nstime_update(&recent->dalloc_time);
+			nstime_prof_update(&recent->dalloc_time);
 			recent->dalloc_tctx = dalloc_tctx;
 			dalloc_tctx = NULL;
 		}