From b4cad00cfb3086490261db7202de8ed846e79344 Mon Sep 17 00:00:00 2001
From: Sebastien GODARD <sysstat@orange.fr.fake>
Date: Wed, 2 Oct 2013 09:55:38 +0200
Subject: [PATCH] pidstat: Display stats since boot time for a list of given
 processes

pidstat displays statistics since system startup when the interval and
count parameters are not set on the command line (eg. entering "pidstat
-d" will display I/O statistics for all processes that have had I/O
activity since boot time). But pidstat couldn't display those stats when
some PID numbers were entered on the command line (eg. "pidstat -d -p
1234" to display I/O stats since system startup for process 1234).
This patch makes it possible now.

Signed-off-by: Sebastien GODARD <sysstat@orange.fr.fake>
(cherry picked from commit 18c7a03f52826942a720b2a0cc32e1f074784c6a)

Resolves: #1448489
---
 pidstat.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/pidstat.c b/pidstat.c
index 3bb98f2..85d4d98 100644
--- a/pidstat.c
+++ b/pidstat.c
@@ -1048,10 +1048,18 @@ int get_pid_to_display(int prev, int curr, int p, unsigned int activity,
 	
 	else if (DISPLAY_PID(pidflag)) {
 		*pstp = st_pid_list[prev] + p;
-
-		if (!(*pstp)->pid)
-			/* PID no longer exists */
-			return 0;
+		if (!(*pstp)->pid) {
+			if (interval)
+				/* PID no longer exists */
+				return 0;
+			else {
+				/*
+				 * If interval is null, then we are trying to
+				 * display stats for a given process since boot time.
+				 */
+				*pstp = &st_pid_null;
+			}
+		}
 	}
 
 	if (COMMAND_STRING(pidflag)) {
-- 
2.13.6