diff --git a/src/swap.c b/src/swap.c
index 7cc668dd2df7e0fc049acfbed7849fe4c57411e9..f906c99dd1413e64819075a0edf2aff2e4a85b51 100644 (file)
--- a/src/swap.c
+++ b/src/swap.c
/* #endif KERNEL_LINUX */
#elif HAVE_LIBKSTAT
-static int pagesize;
+static unsigned long long pagesize;
static kstat_t *ksp;
/* #endif HAVE_LIBKSTAT */
#elif HAVE_LIBKSTAT
/* getpagesize(3C) tells me this does not fail.. */
- pagesize = getpagesize ();
+ pagesize = (unsigned long long) getpagesize ();
if (get_kstat (&ksp, "unix", 0, "system_pages"))
ksp = NULL;
/* #endif HAVE_LIBKSTAT */
unsigned long long swap_alloc;
unsigned long long swap_resv;
unsigned long long swap_avail;
- /* unsigned long long swap_free; */
-
- long long availrmem;
- long long swapfs_minfree;
struct anoninfo ai;
if (swapctl (SC_AINFO, &ai) == -1)
+ {
+ syslog (LOG_ERR, "swap plugin: swapctl failed: %s",
+ strerror (errno));
return;
+ }
- availrmem = get_kstat_value (ksp, "availrmem");
- swapfs_minfree = get_kstat_value (ksp, "minfree");
-
- if ((availrmem < 0LL) || (swapfs_minfree < 0LL))
- return;
-
- /*
- * Calculations learned by reading
- * http://www.itworld.com/Comp/2377/UIR980701perf/
+ /*
+ * Calculations from:
+ * http://cvs.opensolaris.org/source/xref/on/usr/src/cmd/swap/swap.c
+ * Also see:
+ * http://www.itworld.com/Comp/2377/UIR980701perf/ (outdated?)
+ * /usr/include/vm/anon.h
+ *
+ * In short, swap -s shows: allocated + reserved = used, available
+ *
+ * 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
*
- * swap_resv += ani_resv
- * swap_alloc += MAX(ani_resv, ani_max) - ani_free
- * swap_avail += MAX(ani_max - ani_resv, 0) + (availrmem - swapfs_minfree)
- * swap_free += ani_free + (availrmem - swapfs_minfree)
+ * Does your brain hurt yet? - Christophe Kalt
*
- * To clear up the terminology a bit:
- * resv = reserved (but not neccessarily used)
- * alloc = used (neccessarily reserved)
- * avail = not reserved (neccessarily free)
- * free = not allocates (possibly reserved)
+ * Oh, and in case you wonder,
+ * swap_alloc = pagesize * ( ai.ani_max - ai.ani_free );
+ * can suffer from a 32bit overflow.
*/
- swap_resv = pagesize * ai.ani_resv;
- swap_alloc = pagesize * (MAX(ai.ani_resv, ai.ani_max) - ai.ani_free);
- swap_avail = pagesize * (MAX(ai.ani_max - ai.ani_resv, 0) + (availrmem - swapfs_minfree));
- /* swap_free = pagesize * (ai.ani_free + (availrmem - swapfs_minfree)); */
+ swap_alloc = ai.ani_max - ai.ani_free;
+ swap_alloc *= pagesize;
+ swap_resv = ai.ani_resv + ai.ani_free - ai.ani_max;
+ swap_resv *= pagesize;
+ swap_avail = ai.ani_max - ai.ani_resv;
+ swap_avail *= pagesize;
swap_submit (swap_alloc, swap_avail, -1LL, swap_resv - swap_alloc);
/* #endif HAVE_LIBKSTAT */