diff --git a/configure b/configure
index 7c86be3c3d..a1d6081b96 100755
--- a/configure
+++ b/configure
@@ -12892,7 +12892,7 @@ fi
 LIBS_including_readline="$LIBS"
 LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
 
-for ac_func in cbrt clock_gettime dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat pthread_is_threaded_np readlink setproctitle setsid shm_open symlink sync_file_range towlower utime utimes wcstombs wcstombs_l
+for ac_func in cbrt clock_gettime dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pselect pstat pthread_is_threaded_np readlink setproctitle setsid shm_open symlink sync_file_range towlower utime utimes wcstombs wcstombs_l
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
diff --git a/configure.in b/configure.in
index e92494e12d..83e53618e6 100644
--- a/configure.in
+++ b/configure.in
@@ -1429,7 +1429,7 @@ PGAC_FUNC_WCSTOMBS_L
 LIBS_including_readline="$LIBS"
 LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
 
-AC_CHECK_FUNCS([cbrt clock_gettime dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat pthread_is_threaded_np readlink setproctitle setsid shm_open symlink sync_file_range towlower utime utimes wcstombs wcstombs_l])
+AC_CHECK_FUNCS([cbrt clock_gettime dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pselect pstat pthread_is_threaded_np readlink setproctitle setsid shm_open symlink sync_file_range towlower utime utimes wcstombs wcstombs_l])
 
 AC_REPLACE_FUNCS(fseeko)
 case $host_os in
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 2bb4380533..7b9f444dc1 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -614,9 +614,9 @@ PostmasterMain(int argc, char *argv[])
 	 * In the postmaster, we want to install non-ignored handlers *without*
 	 * SA_RESTART.  This is because they'll be blocked at all times except
 	 * when ServerLoop is waiting for something to happen, and during that
-	 * window, we want signals to exit the select(2) wait so that ServerLoop
+	 * window, we want signals to exit the pselect(2) wait so that ServerLoop
 	 * can respond if anything interesting happened.  On some platforms,
-	 * signals marked SA_RESTART would not cause the select() wait to end.
+	 * signals marked SA_RESTART would not cause the pselect() wait to end.
 	 * Child processes will generally want SA_RESTART, but we expect them to
 	 * set up their own handlers before unblocking signals.
 	 *
@@ -1670,6 +1670,8 @@ ServerLoop(void)
 	for (;;)
 	{
 		fd_set		rmask;
+		fd_set	   *rmask_p;
+		struct timeval timeout;
 		int			selres;
 		time_t		now;
 
@@ -1679,37 +1681,64 @@ ServerLoop(void)
 		 * We block all signals except while sleeping. That makes it safe for
 		 * signal handlers, which again block all signals while executing, to
 		 * do nontrivial work.
-		 *
-		 * If we are in PM_WAIT_DEAD_END state, then we don't want to accept
-		 * any new connections, so we don't call select(), and just sleep.
 		 */
-		memcpy((char *) &rmask, (char *) &readmask, sizeof(fd_set));
-
 		if (pmState == PM_WAIT_DEAD_END)
 		{
-			PG_SETMASK(&UnBlockSig);
-
-			pg_usleep(100000L); /* 100 msec seems reasonable */
-			selres = 0;
-
-			PG_SETMASK(&BlockSig);
+			/*
+			 * If we are in PM_WAIT_DEAD_END state, then we don't want to
+			 * accept any new connections, so pass a null rmask.
+			 */
+			rmask_p = NULL;
+			timeout.tv_sec = 0;
+			timeout.tv_usec = 100000;	/* 100 msec seems reasonable */
 		}
 		else
 		{
-			/* must set timeout each time; some OSes change it! */
-			struct timeval timeout;
+			/* Normal case: check sockets, and compute a suitable timeout */
+			memcpy(&rmask, &readmask, sizeof(fd_set));
+			rmask_p = &rmask;
 
 			/* Needs to run with blocked signals! */
 			DetermineSleepTime(&timeout);
-
-			PG_SETMASK(&UnBlockSig);
-
-			selres = select(nSockets, &rmask, NULL, NULL, &timeout);
-
-			PG_SETMASK(&BlockSig);
 		}
 
-		/* Now check the select() result */
+		/*
+		 * We prefer to wait with pselect(2) if available, as using that,
+		 * together with *not* using SA_RESTART for signals, guarantees that
+		 * we will get kicked off the wait if a signal occurs.
+		 *
+		 * If we lack pselect(2), fake it with select(2).  This has a race
+		 * condition: a signal that was already pending will be delivered
+		 * before we reach the select(), and therefore the select() will wait,
+		 * even though we might wish to do something in response.  Therefore,
+		 * beware of putting any time-critical signal response logic into
+		 * ServerLoop rather than into the signal handler itself.  It will run
+		 * eventually, but maybe not till after a timeout delay.
+		 *
+		 * Some implementations of pselect() are reportedly not atomic, making
+		 * the first alternative here functionally equivalent to the second.
+		 * Not much we can do about that though.
+		 */
+		{
+#ifdef HAVE_PSELECT
+			/* pselect uses a randomly different timeout API, sigh */
+			struct timespec ptimeout;
+
+			ptimeout.tv_sec = timeout.tv_sec;
+			ptimeout.tv_nsec = timeout.tv_usec * 1000;
+
+			selres = pselect(nSockets, rmask_p, NULL, NULL,
+							 &ptimeout, &UnBlockSig);
+#else
+			PG_SETMASK(&UnBlockSig);
+
+			selres = select(nSockets, rmask_p, NULL, NULL, &timeout);
+
+			PG_SETMASK(&BlockSig);
+#endif
+		}
+
+		/* Now check the select()/pselect() result */
 		if (selres < 0)
 		{
 			if (errno != EINTR && errno != EWOULDBLOCK)
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 7a05c7e5b8..75e511cfb6 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -400,6 +400,9 @@
 /* Define to 1 if the assembler supports PPC's LWARX mutex hint bit. */
 #undef HAVE_PPC_LWARX_MUTEX_HINT
 
+/* Define to 1 if you have the `pselect' function. */
+#undef HAVE_PSELECT
+
 /* Define to 1 if you have the `pstat' function. */
 #undef HAVE_PSTAT
 
diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32
index 2a5fc1bab7..91d8f61edf 100644
--- a/src/include/pg_config.h.win32
+++ b/src/include/pg_config.h.win32
@@ -267,6 +267,9 @@
 /* Define to 1 if you have the <poll.h> header file. */
 /* #undef HAVE_POLL_H */
 
+/* Define to 1 if you have the `pselect' function. */
+/* #undef HAVE_PSELECT */
+
 /* Define to 1 if you have the `pstat' function. */
 /* #undef HAVE_PSTAT */