--- a/src/processes.c	2009-09-13 12:38:18.000000000 +0200
+++ b/src/processes.c	2009-09-18 17:04:44.599144754 +0200
@@ -136,6 +136,12 @@
 	unsigned long cpu_user_counter;
 	unsigned long cpu_system_counter;
 
+	/* io data */
+	long io_rchar;
+	long io_wchar;
+	long io_syscr;
+	long io_syscw;
+
 	struct procstat_entry_s *next;
 } procstat_entry_t;
 
@@ -159,6 +165,12 @@
 	unsigned long cpu_user_counter;
 	unsigned long cpu_system_counter;
 
+	/* io data */
+	long io_rchar;
+	long io_wchar;
+	long io_syscr;
+	long io_syscw;
+
 	struct procstat   *next;
 	struct procstat_entry_s *instances;
 } procstat_t;
@@ -328,6 +340,10 @@
 		pse->vmem_size  = entry->vmem_size;
 		pse->vmem_rss   = entry->vmem_rss;
 		pse->stack_size = entry->stack_size;
+		pse->io_rchar   = entry->io_rchar;
+		pse->io_wchar   = entry->io_wchar;
+		pse->io_syscr   = entry->io_syscr;
+		pse->io_syscw   = entry->io_syscw;
 
 		ps->num_proc   += pse->num_proc;
 		ps->num_lwp    += pse->num_lwp;
@@ -335,6 +351,11 @@
 		ps->vmem_rss   += pse->vmem_rss;
 		ps->stack_size += pse->stack_size;
 
+		ps->io_rchar   += ((pse->io_rchar == -1)?0:pse->io_rchar);
+		ps->io_wchar   += ((pse->io_wchar == -1)?0:pse->io_wchar);
+		ps->io_syscr   += ((pse->io_syscr == -1)?0:pse->io_syscr);
+		ps->io_syscw   += ((pse->io_syscw == -1)?0:pse->io_syscw);
+
 		if ((entry->vmem_minflt_counter == 0)
 				&& (entry->vmem_majflt_counter == 0))
 		{
@@ -425,6 +446,10 @@
 		ps->vmem_size   = 0;
 		ps->vmem_rss    = 0;
 		ps->stack_size  = 0;
+		ps->io_rchar = -1;
+		ps->io_wchar = -1;
+		ps->io_syscr = -1;
+		ps->io_syscw = -1;
 
 		pse_prev = NULL;
 		pse = ps->instances;
@@ -607,76 +632,110 @@
 	vl.values_len = 2;
 	plugin_dispatch_values (&vl);
 
+	if ( (ps->io_rchar != -1) && (ps->io_wchar != -1) )
+	{
+		sstrncpy (vl.type, "ps_diskbytes", sizeof (vl.type));
+		vl.values[0].counter = ps->io_rchar;
+		vl.values[1].counter = ps->io_wchar;
+		vl.values_len = 2;
+		plugin_dispatch_values (&vl);
+	}
+
+	if ( (ps->io_syscr != -1) && (ps->io_syscw != -1) )
+	{
+		sstrncpy (vl.type, "ps_diskops", sizeof (vl.type));
+		vl.values[0].counter = ps->io_syscr;
+		vl.values[1].counter = ps->io_syscw;
+		vl.values_len = 2;
+		plugin_dispatch_values (&vl);
+	}
+
 	DEBUG ("name = %s; num_proc = %lu; num_lwp = %lu; vmem_rss = %lu; "
 			"vmem_minflt_counter = %lu; vmem_majflt_counter = %lu; "
-			"cpu_user_counter = %lu; cpu_system_counter = %lu;",
+			"cpu_user_counter = %lu; cpu_system_counter = %lu; "
+			"io_rchar = %ld; io_wchar = %ld; "
+			"io_syscr = %ld; io_syscw = %ld;",
 			ps->name, ps->num_proc, ps->num_lwp, ps->vmem_rss,
 			ps->vmem_minflt_counter, ps->vmem_majflt_counter,
-		       	ps->cpu_user_counter, ps->cpu_system_counter);
+			ps->cpu_user_counter, ps->cpu_system_counter,
+			ps->io_rchar, ps->io_wchar, ps->io_syscr, ps->io_syscw);
 } /* void ps_submit_proc_list */
 
 /* ------- additional functions for KERNEL_LINUX/HAVE_THREAD_INFO ------- */
 #if KERNEL_LINUX
-static int *ps_read_tasks (int pid)
+static int ps_read_tasks (int pid)
 {
-	int *list = NULL;
-	int  list_size = 1; /* size of allocated space, in elements */
-	int  list_len = 0;  /* number of currently used elements */
-
 	char           dirname[64];
 	DIR           *dh;
 	struct dirent *ent;
+	int count = 0;
 
 	ssnprintf (dirname, sizeof (dirname), "/proc/%i/task", pid);
 
 	if ((dh = opendir (dirname)) == NULL)
 	{
 		DEBUG ("Failed to open directory `%s'", dirname);
-		return (NULL);
+		return (-1);
 	}
 
 	while ((ent = readdir (dh)) != NULL)
 	{
 		if (!isdigit (ent->d_name[0]))
 			continue;
+		else
+			count++;
+	}
+	closedir (dh);
 
-		if ((list_len + 1) >= list_size)
-		{
-			int *new_ptr;
-			int  new_size = 2 * list_size;
-			/* Comes in sizes: 2, 4, 8, 16, ... */
+	return (count?count:1);
+} /* int *ps_read_tasks */
 
-			new_ptr = (int *) realloc (list, (size_t) (sizeof (int) * new_size));
-			if (new_ptr == NULL)
-			{
-				if (list != NULL)
-					free (list);
-				ERROR ("processes plugin: "
-						"Failed to allocate more memory.");
-				return (NULL);
-			}
+procstat_t *ps_read_io (int pid, procstat_t *ps)
+{
+	FILE *fh;
+	char buffer[1024];
+	char filename[64];
 
-			list = new_ptr;
-			list_size = new_size;
+	char *fields[8];
+	int numfields;
 
-			memset (list + list_len, 0, sizeof (int) * (list_size - list_len));
-		}
+	ssnprintf (filename, sizeof (filename), "/proc/%i/io", pid);
+	if ((fh = fopen (filename, "r")) == NULL)
+		return (NULL);
 
-		list[list_len] = atoi (ent->d_name);
-		if (list[list_len] != 0)
-			list_len++;
-	}
+	while (fgets (buffer, 1024, fh) != NULL)
+	{
+		long *val = NULL;
 
-	closedir (dh);
+		if (strncasecmp (buffer, "rchar:", 6) == 0)
+			val = &(ps->io_rchar);
+		else if (strncasecmp (buffer, "wchar:", 6) == 0)
+			val = &(ps->io_wchar);
+		else if (strncasecmp (buffer, "syscr:", 6) == 0)
+			val = &(ps->io_syscr);
+		else if (strncasecmp (buffer, "syscw:", 6) == 0)
+			val = &(ps->io_syscw);
+		else
+			continue;
 
-	if (list_len == 0)
-		return (NULL);
+		numfields = strsplit (buffer, fields, 8);
 
-	assert (list_len < list_size);
-	assert (list[list_len] == 0);
+		if (numfields < 2)
+			continue;
 
-	return (list);
-} /* int *ps_read_tasks */
+		*val = atol (fields[1]);
+	}
+
+	if (fclose (fh))
+	{
+		char errbuf[1024];
+		WARNING ("processes: fclose: %s",
+				sstrerror (errno, errbuf, sizeof (errbuf)));
+	}
+
+	return (ps);
+
+} /* procstat_t *ps_read_io */
 
 int ps_read_process (int pid, procstat_t *ps, char *state)
 {
@@ -686,7 +745,6 @@
 	char *fields[64];
 	char  fields_len;
 
-	int  *tasks;
 	int   i;
 
 	int   ppid;
@@ -736,21 +794,14 @@
 		ps->num_lwp  = 0;
 		ps->num_proc = 0;
 	}
-	else if ((tasks = ps_read_tasks (pid)) == NULL)
-	{
-		/* Kernel 2.4 or so */
-		ps->num_lwp  = 1;
-		ps->num_proc = 1;
-	}
 	else
 	{
-		ps->num_lwp  = 0;
+		if ( (ps->num_lwp = ps_read_tasks (pid)) == -1 )
+		{
+			/* returns -1 => kernel 2.4 */
+			ps->num_lwp = 1;
+		}
 		ps->num_proc = 1;
-		for (i = 0; tasks[i] != 0; i++)
-			ps->num_lwp++;
-
-		free (tasks);
-		tasks = NULL;
 	}
 
 	/* Leave the rest at zero if this is only a zombi */
@@ -788,6 +839,17 @@
 	ps->vmem_rss = (unsigned long) vmem_rss;
 	ps->stack_size = (unsigned long) stack_size;
 
+	if ( (ps_read_io (pid, ps)) == NULL)
+	{
+		/* no io data */
+		ps->io_rchar = -1;
+		ps->io_wchar = -1;
+		ps->io_syscr = -1;
+		ps->io_syscw = -1;
+
+		DEBUG("ps_read_process: not get io data for pid %i",pid);
+	}
+
 	/* success */
 	return (0);
 } /* int ps_read_process (...) */
@@ -1250,6 +1312,11 @@
 		pse.cpu_system = 0;
 		pse.cpu_system_counter = ps.cpu_system_counter;
 
+		pse.io_rchar = ps.io_rchar;
+		pse.io_wchar = ps.io_wchar;
+		pse.io_syscr = ps.io_syscr;
+		pse.io_syscw = ps.io_syscw;
+
 		switch (state)
 		{
 			case 'R': running++;  break;
--- a/src/types.db	2009-09-13 17:21:40.000000000 +0200
+++ b/src/types.db	2009-09-21 10:57:58.965025226 +0200
@@ -116,6 +116,8 @@
 ps_count		processes:GAUGE:0:1000000, threads:GAUGE:0:1000000
 ps_cputime		user:COUNTER:0:16000000, syst:COUNTER:0:16000000
 ps_pagefaults		minflt:COUNTER:0:9223372036854775807, majflt:COUNTER:0:9223372036854775807
+ps_diskbytes	read:COUNTER:0:16000000, write:COUNTER:0:16000000
+ps_diskops		read:COUNTER:0:16000000, write:COUNTER:0:16000000
 ps_rss			value:GAUGE:0:9223372036854775807
 ps_stacksize		value:GAUGE:0:9223372036854775807
 ps_state		value:GAUGE:0:65535
--- a/src/collectd.conf.pod	2009-09-13 17:21:43.000000000 +0200
+++ b/src/collectd.conf.pod	2009-09-21 11:00:13.357020043 +0200
@@ -2750,7 +2750,7 @@
 Select more detailed statistics of processes matching this name. The statistics
 collected for these selected processes are size of the resident segment size
 (RSS), user- and system-time used, number of processes and number of threads,
-and minor and major pagefaults.
+io data (where available) and minor and major pagefaults.
 
 =item B<ProcessMatch> I<name> I<regex>