diff --git a/include/common/time.h b/include/common/time.h
index abc1ccf..14ca589 100644
--- a/include/common/time.h
+++ b/include/common/time.h
@@ -1,23 +1,23 @@
 /*
-  include/common/time.h
-  Time calculation functions and macros.
-
-  Copyright (C) 2000-2008 Willy Tarreau - w@1wt.eu
-  
-  This library is free software; you can redistribute it and/or
-  modify it under the terms of the GNU Lesser General Public
-  License as published by the Free Software Foundation, version 2.1
-  exclusively.
-
-  This library is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-  Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General Public
-  License along with this library; if not, write to the Free Software
-  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
-*/
+ * include/common/time.h
+ * Time calculation functions and macros.
+ *
+ * Copyright (C) 2000-2011 Willy Tarreau - w@1wt.eu
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, version 2.1
+ * exclusively.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
 
 #ifndef _COMMON_TIME_H
 #define _COMMON_TIME_H
@@ -57,9 +57,14 @@
 extern unsigned int   curr_sec_ms;      /* millisecond of current second (0..999) */
 extern unsigned int   curr_sec_ms_scaled;  /* millisecond of current second (0..2^32-1) */
 extern unsigned int   now_ms;           /* internal date in milliseconds (may wrap) */
+extern unsigned int   samp_time;        /* total elapsed time over current sample */
+extern unsigned int   idle_time;        /* total idle time over current sample */
+extern unsigned int   idle_pct;         /* idle to total ratio over last sample (percent) */
 extern struct timeval now;              /* internal date is a monotonic function of real clock */
 extern struct timeval date;             /* the real current date */
 extern struct timeval start_date;       /* the process's start date */
+extern struct timeval before_poll;      /* system date before calling poll() */
+extern struct timeval after_poll;       /* system date after leaving poll() */
 
 
 /**** exported functions *************************************************/
@@ -516,6 +521,35 @@
 
 char *human_time(int t, short hz_div);
 
+/* Update the idle time value twice a second, to be called after
+ * tv_update_date() when called after poll(). It relies on <before_poll> to be
+ * updated to the system time before calling poll().
+ */
+static inline void measure_idle()
+{
+	/* Let's compute the idle to work ratio. We worked between after_poll
+	 * and before_poll, and slept between before_poll and date. The idle_pct
+	 * is updated at most twice every second. Note that the current second
+	 * rarely changes so we avoid a multiply when not needed.
+	 */
+	int delta;
+
+	if ((delta = date.tv_sec - before_poll.tv_sec))
+		delta *= 1000000;
+	idle_time += delta + (date.tv_usec - before_poll.tv_usec);
+
+	if ((delta = date.tv_sec - after_poll.tv_sec))
+		delta *= 1000000;
+	samp_time += delta + (date.tv_usec - after_poll.tv_usec);
+
+	after_poll.tv_sec = date.tv_sec; after_poll.tv_usec = date.tv_usec;
+	if (samp_time < 500000)
+		return;
+
+	idle_pct = (100 * idle_time + samp_time / 2) / samp_time;
+	idle_time = samp_time = 0;
+}
+
 #endif /* _COMMON_TIME_H */
 
 /*
diff --git a/src/dumpstats.c b/src/dumpstats.c
index 5dcd8c4..ebfb179 100644
--- a/src/dumpstats.c
+++ b/src/dumpstats.c
@@ -1605,6 +1605,7 @@
 				     "MaxConnRate: %d\n"
 				     "Tasks: %d\n"
 				     "Run_queue: %d\n"
+				     "Idle_pct: %d\n"
 				     "node: %s\n"
 				     "description: %s\n"
 				     "",
@@ -1618,7 +1619,7 @@
 				     global.maxsock, global.maxconn, global.hardmaxconn, global.maxpipes,
 				     actconn, pipes_used, pipes_free,
 				     read_freq_ctr(&global.conn_per_sec), global.cps_lim, global.cps_max,
-				     nb_tasks_cur, run_queue_cur,
+				     nb_tasks_cur, run_queue_cur, idle_pct,
 				     global.node, global.desc?global.desc:""
 				     );
 			if (buffer_feed_chunk(si->ib, &msg) >= 0)
@@ -1934,7 +1935,7 @@
 			     "<b>system limits:</b> memmax = %s%s; ulimit-n = %d<br>\n"
 			     "<b>maxsock = </b> %d; <b>maxconn = </b> %d; <b>maxpipes = </b> %d<br>\n"
 			     "current conns = %d; current pipes = %d/%d; conn rate = %d/sec<br>\n"
-			     "Running tasks: %d/%d<br>\n"
+			     "Running tasks: %d/%d; idle = %d %%<br>\n"
 			     "</td><td align=\"center\" nowrap>\n"
 			     "<table class=\"lgd\"><tr>\n"
 			     "<td class=\"active3\">&nbsp;</td><td class=\"noborder\">active UP </td>"
@@ -1967,7 +1968,7 @@
 			     global.rlimit_nofile,
 			     global.maxsock, global.maxconn, global.maxpipes,
 			     actconn, pipes_used, pipes_used+pipes_free, read_freq_ctr(&global.conn_per_sec),
-			     run_queue_cur, nb_tasks_cur
+			     run_queue_cur, nb_tasks_cur, idle_pct
 			     );
 
 			if (si->applet.ctx.stats.flags & STAT_HIDE_DOWN)
diff --git a/src/ev_epoll.c b/src/ev_epoll.c
index 958c4e6..bc7493b 100644
--- a/src/ev_epoll.c
+++ b/src/ev_epoll.c
@@ -236,8 +236,10 @@
 	}
 
 	fd = MIN(maxfd, global.tune.maxpollevents);
+	gettimeofday(&before_poll, NULL);
 	status = epoll_wait(epoll_fd, epoll_events, fd, wait_time);
 	tv_update_date(wait_time, status);
+	measure_idle();
 
 	for (count = 0; count < status; count++) {
 		fd = epoll_events[count].data.fd;
diff --git a/src/ev_kqueue.c b/src/ev_kqueue.c
index e167984..b43533a 100644
--- a/src/ev_kqueue.c
+++ b/src/ev_kqueue.c
@@ -126,6 +126,7 @@
 	}
 
 	fd = MIN(maxfd, global.tune.maxpollevents);
+	gettimeofday(&before_poll, NULL);
 	status = kevent(kqueue_fd, // int kq
 			NULL,      // const struct kevent *changelist
 			0,         // int nchanges
@@ -133,6 +134,7 @@
 			fd,        // int nevents
 			&timeout); // const struct timespec *timeout
 	tv_update_date(delta_ms, status);
+	measure_idle();
 
 	for (count = 0; count < status; count++) {
 		fd = kev[count].ident;
diff --git a/src/ev_poll.c b/src/ev_poll.c
index f5d011e..ec18863 100644
--- a/src/ev_poll.c
+++ b/src/ev_poll.c
@@ -137,8 +137,10 @@
 			wait_time = MAX_DELAY_MS;
 	}
 
+	gettimeofday(&before_poll, NULL);
 	status = poll(poll_events, nbfd, wait_time);
 	tv_update_date(wait_time, status);
+	measure_idle();
 
 	for (count = 0; status > 0 && count < nbfd; count++) {
 		fd = poll_events[count].fd;
diff --git a/src/ev_select.c b/src/ev_select.c
index 5a87282..0924e3f 100644
--- a/src/ev_select.c
+++ b/src/ev_select.c
@@ -125,6 +125,7 @@
 	//	    
 	//	}
 
+	gettimeofday(&before_poll, NULL);
 	status = select(maxfd,
 			readnotnull ? tmp_evts[DIR_RD] : NULL,
 			writenotnull ? tmp_evts[DIR_WR] : NULL,
@@ -132,6 +133,7 @@
 			&delta);
       
 	tv_update_date(delta_ms, status);
+	measure_idle();
 
 	if (status <= 0)
 		return;
diff --git a/src/ev_sepoll.c b/src/ev_sepoll.c
index c9c5978..a7fb64c 100644
--- a/src/ev_sepoll.c
+++ b/src/ev_sepoll.c
@@ -475,8 +475,10 @@
 	/* we want to detect if an accept() will create new speculative FDs here */
 	fd_created = 0;
 	spec_processed = 0;
+	gettimeofday(&before_poll, NULL);
 	status = epoll_wait(epoll_fd, epoll_events, fd, wait_time);
 	tv_update_date(wait_time, status);
+	measure_idle();
 
 	for (count = 0; count < status; count++) {
 		int e = epoll_events[count].events;
diff --git a/src/time.c b/src/time.c
index 1b0f72c..4c41239 100644
--- a/src/time.c
+++ b/src/time.c
@@ -1,7 +1,7 @@
 /*
  * Time calculation functions.
  *
- * Copyright 2000-2009 Willy Tarreau <w@1wt.eu>
+ * Copyright 2000-2011 Willy Tarreau <w@1wt.eu>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -19,9 +19,14 @@
 unsigned int   curr_sec_ms;      /* millisecond of current second (0..999) */
 unsigned int   curr_sec_ms_scaled;  /* millisecond of current second (0..2^32-1) */
 unsigned int   now_ms;          /* internal date in milliseconds (may wrap) */
+unsigned int   samp_time;       /* total elapsed time over current sample */
+unsigned int   idle_time;       /* total idle time over current sample */
+unsigned int   idle_pct;        /* idle to total ratio over last sample (percent) */
 struct timeval now;             /* internal date is a monotonic function of real clock */
 struct timeval date;            /* the real current date */
 struct timeval start_date;      /* the process's start date */
+struct timeval before_poll;     /* system date before calling poll() */
+struct timeval after_poll;      /* system date after leaving poll() */
 
 /*
  * adds <ms> ms to <from>, set the result to <tv> and returns a pointer <tv>
@@ -165,6 +170,9 @@
 	if (unlikely(max_wait < 0)) {
 		tv_zero(&tv_offset);
 		adjusted = date;
+		after_poll = date;
+		samp_time = idle_time = 0;
+		idle_pct = 100;
 		goto to_ms;
 	}
 	__tv_add(&adjusted, &date, &tv_offset);