swap plugin: Add the "ReportBytes" option.

When enabled, swap I/O is reported in bytes, not pages. Only valid for Linux.

This should fix Github issue #10.

diff --git a/src/collectd.conf.in b/src/collectd.conf.in
index 21d0eb1..e508be7 100644 (file)
--- a/src/collectd.conf.in
+++ b/src/collectd.conf.in
@@ -818,6 +818,10 @@ FQDNLookup   true
 #   </Host>
 #</Plugin>
 
+#<Plugin "swap">
+#      ReportBytes true
+#</Plugin>
+
 #<Plugin "table">
 #      <Table "/proc/slabinfo">
 #              Instance "slabinfo"

diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod
index 75f7942..f359e9a 100644 (file)
--- a/src/collectd.conf.pod
+++ b/src/collectd.conf.pod
@@ -4031,6 +4031,23 @@ Since the configuration of the C<snmp plugin> is a little more complicated than
 other plugins, its documentation has been moved to an own manpage,
 L<collectd-snmp(5)>. Please see there for details.
 
+=head2 Plugin C<swap>
+
+The C<swap plugin> reports the number of bytes currently swapped out and the
+amount of swap space available. The precise metrics being exported depends on
+your operating system.
+
+Options:
+
+=over 4
+
+=item B<ReportBytes> B<false>|B<true>
+
+When enabled, the I<swap I/O> is reported in bytes. When disabled, the default,
+I<swap I/O> is reported in pages. This option is available under Linux only.
+
+=back
+
 =head2 Plugin C<syslog>
 
 =over 4

diff --git a/src/swap.c b/src/swap.c
index 46ba665..1a152c9 100644 (file)
--- a/src/swap.c
+++ b/src/swap.c
@@ -1,6 +1,6 @@
 /**
  * collectd - src/swap.c
- * Copyright (C) 2005-2009  Florian octo Forster
+ * Copyright (C) 2005-2012  Florian octo Forster
  * Copyright (C) 2009       Stefan Völkel
  * Copyright (C) 2009       Manuel Sanmartin
  *
@@ -68,7 +68,8 @@
 #define MAX(x,y) ((x) > (y) ? (x) : (y))
 
 #if KERNEL_LINUX
-/* No global variables */
+static derive_t pagesize;
+static _Bool report_bytes = 0;
 /* #endif KERNEL_LINUX */
 
 #elif HAVE_LIBKSTAT
@@ -102,10 +103,16 @@ static perfstat_memory_total_t pmemory;
 # error "No applicable input method."
 #endif /* HAVE_LIBSTATGRAB */
 
+static const char *config_keys[] =
+{
+       "ReportBytes"
+};
+static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
+
 static int swap_init (void)
 {
 #if KERNEL_LINUX
-       /* No init stuff */
+       pagesize = (derive_t) sysconf (_SC_PAGESIZE);
 /* #endif KERNEL_LINUX */
 
 #elif HAVE_LIBKSTAT
@@ -284,6 +291,12 @@ static int swap_read (void)
                                sstrerror (errno, errbuf, sizeof (errbuf)));
        }
 
+       if (report_bytes)
+       {
+               swap_in  *= pagesize;
+               swap_out *= pagesize;
+       }
+
        swap_submit ("used",   1024 * swap_used,   DS_TYPE_GAUGE);
        swap_submit ("free",   1024 * swap_free,   DS_TYPE_GAUGE);
        swap_submit ("cached", 1024 * swap_cached, DS_TYPE_GAUGE);
@@ -490,8 +503,30 @@ static int swap_read (void)
        return (0);
 } /* int swap_read */
 
+static int swap_config (const char *key, const char *value)
+{
+       if (strcasecmp ("ReportBytes", key) == 0)
+       {
+#if KERNEL_LINUX
+               report_bytes = IS_TRUE (value) ? 1 : 0;
+#else
+               WARNING ("swap plugin: The \"ReportBytes\" option is only "
+                               "valid under Linux. The option is going to "
+                               "be ignored.");
+#endif
+       }
+       else
+       {
+               return (-1);
+       }
+
+       return (0);
+} /* int swap_config */
+
 void module_register (void)
 {
+       plugin_register_config ("swap", swap_config,
+                       config_keys, config_keys_num);
        plugin_register_init ("swap", swap_init);
        plugin_register_read ("swap", swap_read);
 } /* void module_register */