swap plugin - swap in/out does not work for kernels <2.6

It works on RedHat9 and 6 (don't ask). A more gracefull solution is
having a configuration option for choosing /proc/<foo> format I
suppose...
Hope it helps some sysadmins like me that are forced to maintained
anqituities in production.

Cheers

From 1da38c6d515f7fa4599b7b08e1284fb2ac9a504a Mon Sep 17 00:00:00 2001
From: Lorin Scraba <lorin@si-bemol.ro>
Date: Tue, 19 Jan 2010 15:16:29 -0800
Subject: [PATCH] swap plugin - swapin/out fix for older kernels - <2.6

Signed-off-by: Lorin Scraba <lorin@si-bemol.ro>
Signed-off-by: Florian Forster <octo@huhu.verplant.org>

diff --git a/src/swap.c b/src/swap.c
index 7f41c9e..63a5c89 100644 (file)
--- a/src/swap.c
+++ b/src/swap.c
@@ -193,6 +193,8 @@ static int swap_read (void)
        char *fields[8];
        int numfields;
 
+       unsigned int old_kernel=0;
+
        derive_t swap_used   = 0;
        derive_t swap_cached = 0;
        derive_t swap_free   = 0;
@@ -243,31 +245,49 @@ 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);
-       }
-
-       while (fgets (buffer, 1024, 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;
+               // /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
-                       continue;
-
-               numfields = strsplit (buffer, fields, 8);
-
-               if (numfields < 2)
-                       continue;
-
-               *val = (derive_t) atoll (fields[1]);
+                       old_kernel = 1;
        }
 
+       if ( old_kernel ) 
+               while (fgets (buffer, 1024, fh) != NULL)
+               {
+                       if (strncasecmp (buffer, "page",4) == 0) 
+                       {
+                               numfields = strsplit(buffer,fields,3);
+                               if ( numfields < 3 )
+                                       continue;
+                               swap_in  = (derive_t) atoll(fields[1]);
+                               swap_out = (derive_t) atoll(fields[2]);
+                       }
+               }
+       else 
+               while (fgets (buffer, 1024, 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]);
+               }
+
        if (fclose (fh))
        {
                char errbuf[1024];