swap plugin: Fix a bug collecting swap I/O.

[collectd.git] / src / swap.c

diff --git a/src/swap.c b/src/swap.c
index 7f41c9e..46ba665 100644 (file)
--- a/src/swap.c
+++ b/src/swap.c
@@ -96,7 +96,7 @@ int kvm_pagesize;
 #elif HAVE_PERFSTAT
 static int pagesize;
 static perfstat_memory_total_t pmemory;
-/*# endif HAVE_PERFSTAT */ 
+/*# endif HAVE_PERFSTAT */
 
 #else
 # error "No applicable input method."
@@ -193,6 +193,8 @@ static int swap_read (void)
        char *fields[8];
        int numfields;
 
+       _Bool old_kernel=0;
+
        derive_t swap_used   = 0;
        derive_t swap_cached = 0;
        derive_t swap_free   = 0;
@@ -208,25 +210,18 @@ static int swap_read (void)
                return (-1);
        }
 
-       while (fgets (buffer, 1024, fh) != NULL)
+       while (fgets (buffer, sizeof (buffer), fh) != NULL)
        {
-               derive_t *val = NULL;
-
-               if (strncasecmp (buffer, "SwapTotal:", 10) == 0)
-                       val = &swap_total;
-               else if (strncasecmp (buffer, "SwapFree:", 9) == 0)
-                       val = &swap_free;
-               else if (strncasecmp (buffer, "SwapCached:", 11) == 0)
-                       val = &swap_cached;
-               else
-                       continue;
-
-               numfields = strsplit (buffer, fields, 8);
-
+               numfields = strsplit (buffer, fields, STATIC_ARRAY_SIZE (fields));
                if (numfields < 2)
                        continue;
 
-               *val = (derive_t) atoll (fields[1]) * 1024LL;
+               if (strcasecmp (fields[0], "SwapTotal:") == 0)
+                       strtoderive (fields[1], &swap_total);
+               else if (strcasecmp (fields[0], "SwapFree:") == 0)
+                       strtoderive (fields[1], &swap_free);
+               else if (strcasecmp (fields[0], "SwapCached:") == 0)
+                       strtoderive (fields[1], &swap_cached);
        }
 
        if (fclose (fh))
@@ -243,30 +238,44 @@ static int swap_read (void)
 
        if ((fh = fopen ("/proc/vmstat", "r")) == NULL)
        {
-               char errbuf[1024];
-               WARNING ("swap: fopen: %s",
-                               sstrerror (errno, errbuf, sizeof (errbuf)));
-               return (-1);
+               // /proc/vmstat does not exist in kernels <2.6
+               if ((fh = fopen ("/proc/stat", "r")) == NULL )
+               {
+                       char errbuf[1024];
+                       WARNING ("swap: fopen: %s",
+                                       sstrerror (errno, errbuf, sizeof (errbuf)));
+                       return (-1);
+               }
+               else
+                       old_kernel = 1;
        }
 
-       while (fgets (buffer, 1024, fh) != NULL)
+       while (fgets (buffer, sizeof (buffer), fh) != NULL)
        {
-               derive_t *val = NULL;
-
-               if (strncasecmp (buffer, "pswpin", 6) == 0)
-                       val = &swap_in;
-               else if (strncasecmp (buffer, "pswpout", 7) == 0)
-                       val = &swap_out;
-               else
-                       continue;
-
-               numfields = strsplit (buffer, fields, 8);
-
-               if (numfields < 2)
-                       continue;
-
-               *val = (derive_t) atoll (fields[1]);
-       }
+               numfields = strsplit (buffer, fields, STATIC_ARRAY_SIZE (fields));
+
+               if (!old_kernel)
+               {
+                       if (numfields != 2)
+                               continue;
+
+                       if (strcasecmp ("pswpin", fields[0]) == 0)
+                               strtoderive (fields[1], &swap_in);
+                       else if (strcasecmp ("pswpout", fields[0]) == 0)
+                               strtoderive (fields[1], &swap_out);
+               }
+               else /* if (old_kernel) */
+               {
+                       if (numfields != 3)
+                               continue;
+
+                       if (strcasecmp ("page", fields[0]) == 0)
+                       {
+                               strtoderive (fields[1], &swap_in);
+                               strtoderive (fields[2], &swap_out);
+                       }
+               }
+       } /* while (fgets) */
 
        if (fclose (fh))
        {
@@ -275,12 +284,11 @@ static int swap_read (void)
                                sstrerror (errno, errbuf, sizeof (errbuf)));
        }
 
-       swap_submit ("used", swap_used, DS_TYPE_GAUGE);
-       swap_submit ("free", swap_free, DS_TYPE_GAUGE);
-       swap_submit ("cached", swap_cached, DS_TYPE_GAUGE);
-       swap_submit ("in", swap_in, DS_TYPE_DERIVE);
+       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);
+       swap_submit ("in",  swap_in,  DS_TYPE_DERIVE);
        swap_submit ("out", swap_out, DS_TYPE_DERIVE);
-
 /* #endif KERNEL_LINUX */
 
 #elif HAVE_LIBKSTAT
@@ -310,7 +318,7 @@ static int swap_read (void)
         * However, Solaris does not allow to allocated/reserved more than the
         * available swap (physical memory + disk swap), so the pedant may
         * prefer: allocated + unallocated = reserved, available
-        * 
+        *
         * We map the above to: used + resv = n/a, free
         *
         * Does your brain hurt yet?  - Christophe Kalt