freebsd swap metrics

src/os/darwin/darwin_sigar.c

@@ -11,6 +11,7 @@
 #include <sys/types.h>
 #include <sys/param.h>
 #include <sys/user.h>
+#include <fcntl.h>
 #endif
 
 #include <sys/ioctl.h>
@@ -55,6 +56,8 @@ int sigar_os_open(sigar_t **sigar)
 
 #ifdef DARWIN
     (*sigar)->mach_port = mach_host_self();
+#else
+    (*sigar)->kp = kvm_open(NULL, NULL, NULL, O_RDONLY, "kvm_open");
 #endif
 
     (*sigar)->ncpu = ncpu;
@@ -193,10 +196,22 @@ int sigar_swap_get(sigar_t *sigar, sigar_swap_t *swap)
     swap->free = swap->total - swap->used;
 
 #else
-    /*XXX*/
+    struct kvm_swap kswap[1];
+
+    if (kvm_getswapinfo(sigar->kp, kswap, 1, 0) < 0) {
+        return errno;
+    }
+
+    if (kswap[0].ksw_total == 0) {
         swap->total = 0;
         swap->used  = 0;
         swap->free  = 0;
+        return SIGAR_OK;
+    }
+
+    swap->total = kswap[0].ksw_total * sigar->pagesize;
+    swap->used  = kswap[0].ksw_used * sigar->pagesize;
+    swap->free  = swap->total - swap->used;
 #endif
 
     return SIGAR_OK;

src/os/darwin/sigar_os.h

@@ -4,6 +4,8 @@
 #ifdef DARWIN
 #include <mach/port.h>
 #include <mach/host_info.h>
+#else
+#include <kvm.h>
 #endif
 
 #include <sys/sysctl.h>
@@ -16,6 +18,8 @@ struct sigar_t {
     struct kinfo_proc *pinfo;
 #ifdef DARWIN
     mach_port_t mach_port;
+#else
+    kvm_t *kp;
 #endif
 };