zfs_arc plugin: Use a buffer with fixed size rather than allocating on the heap.

[collectd.git] / src / zfs_arc.c

diff --git a/src/zfs_arc.c b/src/zfs_arc.c
index aa900193b834e32b5d71c282f11663fe824a4e47..6bf7daef7479020a2a024c1eba08b09393c0c2bf 100644 (file)
--- a/src/zfs_arc.c
+++ b/src/zfs_arc.c
@@ -2,6 +2,7 @@
  * collectd - src/zfs_arc.c
  * Copyright (C) 2009  Anthony Dewhurst
  * Copyright (C) 2012  Aurelien Rougemont
+ * Copyright (C) 2013  Xin Li
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -19,6 +20,7 @@
  * Authors:
  *   Anthony Dewhurst <dewhurst at gmail>
  *   Aurelien Rougemont <beorn at gandi.net>
+ *   Xin Li <delphij at FreeBSD.org>
  **/
 
 #include "collectd.h"
@@ -29,8 +31,42 @@
  * Global variables
  */
 
+#if !defined(__FreeBSD__)
 extern kstat_ctl_t *kc;
 
+static long long get_zfs_value(kstat_t *ksp, char *name)
+{
+
+       return (get_kstat_value(ksp, name));
+}
+#else
+#include <sys/types.h>
+#include <sys/sysctl.h>
+
+const char zfs_arcstat[] = "kstat.zfs.misc.arcstats.";
+
+#if !defined(kstat_t)
+typedef void kstat_t;
+#endif
+
+static long long get_zfs_value(kstat_t *dummy __attribute__((unused)),
+               char const *name)
+{
+       char buffer[256];
+       long long value;
+       size_t valuelen = sizeof(value);
+       int rv;
+
+       ssnprintf (buffer, sizeof (buffer), "%s%s", zfs_arcstat, name);
+       rv = sysctlbyname (buffer, (void *) &value, &valuelen,
+                       /* new value = */ NULL, /* new length = */ (size_t) 0);
+       if (rv == 0)
+               return (value);
+
+       return (-1);
+}
+#endif
+
 static void za_submit (const char* type, const char* type_instance, value_t* values, int values_len)
 {
        value_list_t vl = VALUE_LIST_INIT;
@@ -60,7 +96,7 @@ static int za_read_derive (kstat_t *ksp, const char *kstat_value,
   long long tmp;
   value_t v;
 
-  tmp = get_kstat_value (ksp, (char *)kstat_value);
+  tmp = get_zfs_value (ksp, (char *)kstat_value);
   if (tmp == -1LL)
   {
     ERROR ("zfs_arc plugin: Reading kstat value \"%s\" failed.", kstat_value);
@@ -78,7 +114,7 @@ static int za_read_gauge (kstat_t *ksp, const char *kstat_value,
   long long tmp;
   value_t v;
 
-  tmp = get_kstat_value (ksp, (char *)kstat_value);
+  tmp = get_zfs_value (ksp, (char *)kstat_value);
   if (tmp == -1LL)
   {
     ERROR ("zfs_arc plugin: Reading kstat value \"%s\" failed.", kstat_value);
@@ -111,12 +147,14 @@ static int za_read (void)
        value_t  l2_io[2];
        kstat_t  *ksp   = NULL;
 
+#if !defined(__FreeBSD__)
        get_kstat (&ksp, "zfs", 0, "arcstats");
        if (ksp == NULL)
        {
                ERROR ("zfs_arc plugin: Cannot find zfs:0:arcstats kstat.");
                return (-1);
        }
+#endif
 
        /* Sizes */
        za_read_gauge (ksp, "size",    "cache_size", "arc");
@@ -147,17 +185,17 @@ static int za_read (void)
        za_read_derive (ksp, "prefetch_metadata_misses", "cache_result", "prefetch_metadata-miss");
 
        /* Ratios */
-       arc_hits   = (gauge_t) get_kstat_value(ksp, "hits");
-       arc_misses = (gauge_t) get_kstat_value(ksp, "misses");
-       l2_hits    = (gauge_t) get_kstat_value(ksp, "l2_hits");
-       l2_misses  = (gauge_t) get_kstat_value(ksp, "l2_misses");
+       arc_hits   = (gauge_t) get_zfs_value(ksp, "hits");
+       arc_misses = (gauge_t) get_zfs_value(ksp, "misses");
+       l2_hits    = (gauge_t) get_zfs_value(ksp, "l2_hits");
+       l2_misses  = (gauge_t) get_zfs_value(ksp, "l2_misses");
 
        za_submit_ratio ("arc", arc_hits, arc_misses);
        za_submit_ratio ("L2", l2_hits, l2_misses);
 
        /* I/O */
-       l2_io[0].derive = get_kstat_value(ksp, "l2_read_bytes");
-       l2_io[1].derive = get_kstat_value(ksp, "l2_write_bytes");
+       l2_io[0].derive = get_zfs_value(ksp, "l2_read_bytes");
+       l2_io[1].derive = get_zfs_value(ksp, "l2_write_bytes");
 
        za_submit ("io_octets", "L2", l2_io, /* num values = */ 2);
 
@@ -166,12 +204,14 @@ static int za_read (void)
 
 static int za_init (void) /* {{{ */
 {
+#if !defined(__FreeBSD__)
        /* kstats chain already opened by update_kstat (using *kc), verify everything went fine. */
        if (kc == NULL)
        {
                ERROR ("zfs_arc plugin: kstat chain control structure not available.");
                return (-1);
        }
+#endif
 
        return (0);
 } /* }}} int za_init */