diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 8a5b2b3b42..8de603d193 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -2784,21 +2784,13 @@ pgstat_initialize(void)
 void
 pgstat_bestart(void)
 {
-	TimestampTz proc_start_timestamp;
 	SockAddr	clientaddr;
 	volatile PgBackendStatus *beentry;
 
 	/*
 	 * To minimize the time spent modifying the PgBackendStatus entry, fetch
 	 * all the needed data first.
-	 *
-	 * If we have a MyProcPort, use its session start time (for consistency,
-	 * and to save a kernel call).
 	 */
-	if (MyProcPort)
-		proc_start_timestamp = MyProcPort->SessionStartTime;
-	else
-		proc_start_timestamp = GetCurrentTimestamp();
 
 	/*
 	 * We may not have a MyProcPort (eg, if this is the autovacuum process).
@@ -2883,7 +2875,7 @@ pgstat_bestart(void)
 	} while ((beentry->st_changecount & 1) == 0);
 
 	beentry->st_procpid = MyProcPid;
-	beentry->st_proc_start_timestamp = proc_start_timestamp;
+	beentry->st_proc_start_timestamp = MyStartTimestamp;
 	beentry->st_activity_start_timestamp = 0;
 	beentry->st_state_start_timestamp = 0;
 	beentry->st_xact_start_timestamp = 0;
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 41de140ae0..688f462e7d 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -129,6 +129,7 @@
 #include "utils/pidfile.h"
 #include "utils/ps_status.h"
 #include "utils/timeout.h"
+#include "utils/timestamp.h"
 #include "utils/varlena.h"
 
 #ifdef EXEC_BACKEND
@@ -581,9 +582,9 @@ PostmasterMain(int argc, char *argv[])
 	int			i;
 	char	   *output_config_variable = NULL;
 
-	MyProcPid = PostmasterPid = getpid();
+	InitProcessGlobals();
 
-	MyStartTime = time(NULL);
+	PostmasterPid = MyProcPid;
 
 	IsPostmasterEnvironment = true;
 
@@ -597,16 +598,6 @@ PostmasterMain(int argc, char *argv[])
 	 */
 	umask(PG_MODE_MASK_OWNER);
 
-	/*
-	 * Initialize random(3) so we don't get the same values in every run.
-	 *
-	 * Note: the seed is pretty predictable from externally-visible facts such
-	 * as postmaster start time, so avoid using random() for security-critical
-	 * random values during postmaster startup.  At the time of first
-	 * connection, PostmasterRandom will select a hopefully-more-random seed.
-	 */
-	srandom((unsigned int) (MyProcPid ^ MyStartTime));
-
 	/*
 	 * By default, palloc() requests in the postmaster will be allocated in
 	 * the PostmasterContext, which is space that can be recycled by backends.
@@ -2513,6 +2504,32 @@ ClosePostmasterPorts(bool am_syslogger)
 }
 
 
+/*
+ * InitProcessGlobals -- set MyProcPid, MyStartTime[stamp], random seeds
+ *
+ * Called early in every backend.
+ */
+void
+InitProcessGlobals(void)
+{
+	MyProcPid = getpid();
+	MyStartTimestamp = GetCurrentTimestamp();
+	MyStartTime = timestamptz_to_time_t(MyStartTimestamp);
+
+	/*
+	 * Don't want backend to be able to see the postmaster random number
+	 * generator state.  We have to clobber the static random_seed.
+	 */
+#ifndef HAVE_STRONG_RANDOM
+	random_seed = 0;
+	random_start_time.tv_usec = 0;
+#endif
+
+	/* Set a different seed for random() in every backend. */
+	srandom((unsigned int) MyProcPid ^ (unsigned int) MyStartTimestamp);
+}
+
+
 /*
  * reset_shared -- reset shared memory and semaphores
  */
@@ -4154,10 +4171,6 @@ BackendInitialize(Port *port)
 	/* This flag will remain set until InitPostgres finishes authentication */
 	ClientAuthInProgress = true;	/* limit visibility of log messages */
 
-	/* save process start time */
-	port->SessionStartTime = GetCurrentTimestamp();
-	MyStartTime = timestamptz_to_time_t(port->SessionStartTime);
-
 	/* set these to empty in case they are needed before we set them up */
 	port->remote_host = "";
 	port->remote_port = "";
@@ -4315,23 +4328,8 @@ BackendRun(Port *port)
 	char	  **av;
 	int			maxac;
 	int			ac;
-	long		secs;
-	int			usecs;
 	int			i;
 
-	/*
-	 * Don't want backend to be able to see the postmaster random number
-	 * generator state.  We have to clobber the static random_seed *and* start
-	 * a new random sequence in the random() library function.
-	 */
-#ifndef HAVE_STRONG_RANDOM
-	random_seed = 0;
-	random_start_time.tv_usec = 0;
-#endif
-	/* slightly hacky way to convert timestamptz into integers */
-	TimestampDifference(0, port->SessionStartTime, &secs, &usecs);
-	srandom((unsigned int) (MyProcPid ^ (usecs << 12) ^ secs));
-
 	/*
 	 * Now, build the argv vector that will be given to PostgresMain.
 	 *
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index e4c6e3d406..6e13d14fcd 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -4632,7 +4632,7 @@ log_disconnections(int code, Datum arg)
 				minutes,
 				seconds;
 
-	TimestampDifference(port->SessionStartTime,
+	TimestampDifference(MyStartTimestamp,
 						GetCurrentTimestamp(),
 						&secs, &usecs);
 	msecs = usecs / 1000;
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 5971310aab..c6939779b9 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -39,6 +39,7 @@ volatile uint32 CritSectionCount = 0;
 
 int			MyProcPid;
 pg_time_t	MyStartTime;
+TimestampTz	MyStartTimestamp;
 struct Port *MyProcPort;
 int32		MyCancelKey;
 int			MyPMChildSlot;
diff --git a/src/backend/utils/init/miscinit.c b/src/backend/utils/init/miscinit.c
index f590ecb25e..238fe1deec 100644
--- a/src/backend/utils/init/miscinit.c
+++ b/src/backend/utils/init/miscinit.c
@@ -274,9 +274,7 @@ InitPostmasterChild(void)
 {
 	IsUnderPostmaster = true;	/* we are a postmaster subprocess now */
 
-	MyProcPid = getpid();		/* reset MyProcPid */
-
-	MyStartTime = time(NULL);	/* set our start time in case we call elog */
+	InitProcessGlobals();
 
 	/*
 	 * make sure stderr is in binary mode before anything can possibly be
@@ -321,17 +319,7 @@ InitStandaloneProcess(const char *argv0)
 {
 	Assert(!IsPostmasterEnvironment);
 
-	MyProcPid = getpid();		/* reset MyProcPid */
-
-	MyStartTime = time(NULL);	/* set our start time in case we call elog */
-
-	/*
-	 * Initialize random() for the first time, like PostmasterMain() would.
-	 * In a regular IsUnderPostmaster backend, BackendRun() computes a
-	 * high-entropy seed before any user query.  Fewer distinct initial seeds
-	 * can occur here.
-	 */
-	srandom((unsigned int) (MyProcPid ^ MyStartTime));
+	InitProcessGlobals();
 
 	/* Initialize process-local latch support */
 	InitializeLatchSupport();
diff --git a/src/include/libpq/libpq-be.h b/src/include/libpq/libpq-be.h
index eb8bba4ed8..b2c59df54e 100644
--- a/src/include/libpq/libpq-be.h
+++ b/src/include/libpq/libpq-be.h
@@ -150,13 +150,6 @@ typedef struct Port
 	 */
 	HbaLine    *hba;
 
-	/*
-	 * Information that really has no business at all being in struct Port,
-	 * but since it gets used by elog.c in the same way as database_name and
-	 * other members of this struct, we may as well keep it here.
-	 */
-	TimestampTz SessionStartTime;	/* backend start time */
-
 	/*
 	 * TCP keepalive settings.
 	 *
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index 69f356f8cd..d6b32c070c 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -25,6 +25,7 @@
 
 #include <signal.h>
 
+#include "datatype/timestamp.h"	/* for TimestampTZ */
 #include "pgtime.h"				/* for pg_time_t */
 
 
@@ -163,6 +164,7 @@ extern PGDLLIMPORT int max_parallel_workers;
 
 extern PGDLLIMPORT int MyProcPid;
 extern PGDLLIMPORT pg_time_t MyStartTime;
+extern PGDLLIMPORT TimestampTz MyStartTimestamp;
 extern PGDLLIMPORT struct Port *MyProcPort;
 extern PGDLLIMPORT struct Latch *MyLatch;
 extern int32 MyCancelKey;
diff --git a/src/include/postmaster/postmaster.h b/src/include/postmaster/postmaster.h
index 1877eef239..a40d66e890 100644
--- a/src/include/postmaster/postmaster.h
+++ b/src/include/postmaster/postmaster.h
@@ -48,6 +48,7 @@ extern PGDLLIMPORT const char *progname;
 
 extern void PostmasterMain(int argc, char *argv[]) pg_attribute_noreturn();
 extern void ClosePostmasterPorts(bool am_syslogger);
+extern void InitProcessGlobals(void);
 
 extern int	MaxLivePostmasterChildren(void);