Fix case when availrmem < freemem

Change-Id: I03b188afeb2357e7b8c426bd0c6daff06fda2c4f

Conflicts:

	src/memory.c

diff --git a/src/memory.c b/src/memory.c
index d1cd326..6a50161 100644 (file)
--- a/src/memory.c
+++ b/src/memory.c
@@ -331,6 +331,7 @@ static int memory_read (void)
 
        long long pp_kernel;
        long long physmem;
+       long long availrmem;
 
        if (ksp == NULL)
                return (-1);
@@ -343,14 +344,32 @@ static int memory_read (void)
 
        pp_kernel = get_kstat_value (ksp, "pp_kernel");
        physmem = get_kstat_value (ksp, "physmem");
+       availrmem = get_kstat_value (ksp, "availrmem");
 
        if ((mem_used < 0LL) || (mem_free < 0LL) || (mem_lock < 0LL))
+       {
+               WARNING ("memory plugin: one of used, free or locked is negative.");
                return (-1);
-       if (mem_used < (mem_free + mem_lock))
-               return (-1);
+       }
 
        mem_unus = physmem - mem_used;
-       mem_used -= mem_free + mem_lock;
+
+       if (mem_used < (mem_free + mem_lock))
+       {
+               /* source: http://wesunsolve.net/bugid/id/4909199
+                * this seems to happen when swap space is small, e.g. 2G on a 32G system
+                * we will make some assumptions here
+                * educated solaris internals help welcome here */
+               DEBUG ("memory plugin: pages total is smaller than \"free\" "
+                               "+ \"locked\". This is probably due to small "
+                               "swap space");
+               mem_free = availrmem;
+               mem_used = 0;
+       }
+       else
+       {
+               mem_used -= mem_free + mem_lock;
+       }
 
        /* mem_kern is accounted for in mem_lock */
        if ( pp_kernel < mem_lock )