2 * collectd - src/zfs_arc.c
3 * Copyright (C) 2009 Anthony Dewhurst
4 * Copyright (C) 2012 Aurelien Rougemont
5 * Copyright (C) 2013 Xin Li
6 * Copyright (C) 2014 Marc Fournier
7 * Copyright (C) 2014 Wilfried Goesgens
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; only version 2 of the License is applicable.
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
23 * Anthony Dewhurst <dewhurst at gmail>
24 * Aurelien Rougemont <beorn at gandi.net>
25 * Xin Li <delphij at FreeBSD.org>
26 * Marc Fournier <marc.fournier at camptocamp.com>
27 * Wilfried Goesgens <dothebart at citadel.org>
38 static value_to_rate_state_t arc_hits_state;
39 static value_to_rate_state_t arc_misses_state;
40 static value_to_rate_state_t l2_hits_state;
41 static value_to_rate_state_t l2_misses_state;
43 #if defined(KERNEL_LINUX)
44 #include "utils_llist.h"
45 #define ZOL_ARCSTATS_FILE "/proc/spl/kstat/zfs/arcstats"
47 typedef llist_t kstat_t;
49 static int put_zfs_value(kstat_t *ksp, char const *k, value_t v) {
58 v_copy = malloc(sizeof(*v_copy));
65 e = llentry_create(k_copy, v_copy);
76 static long long get_zfs_value(kstat_t *ksp, const char *key) {
80 e = llist_search(ksp, key);
86 return (long long)v->derive;
89 static void free_zfs_values(kstat_t *ksp) {
93 for (llentry_t *e = llist_head(ksp); e != NULL; e = e->next) {
101 #elif defined(KERNEL_SOLARIS)
102 extern kstat_ctl_t *kc;
104 static long long get_zfs_value(kstat_t *ksp, char *name) {
106 return get_kstat_value(ksp, name);
108 #elif defined(KERNEL_FREEBSD)
109 #include <sys/sysctl.h>
110 #include <sys/types.h>
112 const char zfs_arcstat[] = "kstat.zfs.misc.arcstats.";
114 #if !defined(kstat_t)
115 typedef void kstat_t;
118 static long long get_zfs_value(kstat_t *dummy __attribute__((unused)),
122 size_t valuelen = sizeof(value);
125 snprintf(buffer, sizeof(buffer), "%s%s", zfs_arcstat, name);
126 rv = sysctlbyname(buffer, (void *)&value, &valuelen,
127 /* new value = */ NULL, /* new length = */ (size_t)0);
135 static void za_submit(const char *type, const char *type_instance,
136 value_t *values, size_t values_len) {
137 value_list_t vl = VALUE_LIST_INIT;
140 vl.values_len = values_len;
142 sstrncpy(vl.plugin, "zfs_arc", sizeof(vl.plugin));
143 sstrncpy(vl.type, type, sizeof(vl.type));
144 sstrncpy(vl.type_instance, type_instance, sizeof(vl.type_instance));
146 plugin_dispatch_values(&vl);
149 static void za_submit_gauge(const char *type, const char *type_instance,
151 za_submit(type, type_instance, &(value_t){.gauge = value}, 1);
154 static int za_read_derive(kstat_t *ksp, const char *kstat_value,
155 const char *type, const char *type_instance) {
156 long long tmp = get_zfs_value(ksp, (char *)kstat_value);
158 DEBUG("zfs_arc plugin: Reading kstat value \"%s\" failed.", kstat_value);
162 za_submit(type, type_instance, &(value_t){.derive = (derive_t)tmp},
163 /* values_num = */ 1);
167 static int za_read_gauge(kstat_t *ksp, const char *kstat_value,
168 const char *type, const char *type_instance) {
169 long long tmp = get_zfs_value(ksp, (char *)kstat_value);
171 DEBUG("zfs_arc plugin: Reading kstat value \"%s\" failed.", kstat_value);
175 za_submit(type, type_instance, &(value_t){.gauge = (gauge_t)tmp},
176 /* values_num = */ 1);
180 static void za_submit_ratio(const char *type_instance, gauge_t hits,
184 if (!isfinite(hits) || (hits < 0.0))
186 if (!isfinite(misses) || (misses < 0.0))
189 if ((hits != 0.0) || (misses != 0.0))
190 ratio = hits / (hits + misses);
192 za_submit_gauge("cache_ratio", type_instance, ratio);
195 static int za_read(void) {
196 gauge_t arc_hits, arc_misses, l2_hits, l2_misses;
199 #if defined(KERNEL_LINUX)
203 fh = fopen(ZOL_ARCSTATS_FILE, "r");
205 ERROR("zfs_arc plugin: Opening \"%s\" failed: %s", ZOL_ARCSTATS_FILE,
210 /* Ignore the first two lines because they contain information about the rest
212 * See kstat_seq_show_headers module/spl/spl-kstat.c of the spl kernel module.
214 if ((fgets(buffer, sizeof(buffer), fh) == NULL) ||
215 (fgets(buffer, sizeof(buffer), fh) == NULL)) {
216 ERROR("zfs_arc plugin: \"%s\" does not contain at least two lines.",
222 ksp = llist_create();
224 ERROR("zfs_arc plugin: `llist_create' failed.");
229 while (fgets(buffer, sizeof(buffer), fh) != NULL) {
234 status = strsplit(buffer, fields, STATIC_ARRAY_SIZE(fields));
238 status = parse_value(fields[2], &v, DS_TYPE_DERIVE);
242 put_zfs_value(ksp, fields[0], v);
247 #elif defined(KERNEL_SOLARIS)
248 get_kstat(&ksp, "zfs", 0, "arcstats");
250 ERROR("zfs_arc plugin: Cannot find zfs:0:arcstats kstat.");
256 za_read_gauge(ksp, "anon_size", "cache_size", "anon_size");
257 za_read_gauge(ksp, "c", "cache_size", "c");
258 za_read_gauge(ksp, "c_max", "cache_size", "c_max");
259 za_read_gauge(ksp, "c_min", "cache_size", "c_min");
260 za_read_gauge(ksp, "hdr_size", "cache_size", "hdr_size");
261 za_read_gauge(ksp, "metadata_size", "cache_size", "metadata_size");
262 za_read_gauge(ksp, "mfu_ghost_size", "cache_size", "mfu_ghost_size");
263 za_read_gauge(ksp, "mfu_size", "cache_size", "mfu_size");
264 za_read_gauge(ksp, "mru_ghost_size", "cache_size", "mru_ghost_size");
265 za_read_gauge(ksp, "mru_size", "cache_size", "mru_size");
266 za_read_gauge(ksp, "other_size", "cache_size", "other_size");
267 za_read_gauge(ksp, "p", "cache_size", "p");
268 za_read_gauge(ksp, "size", "cache_size", "arc");
270 /* The "l2_size" value has disappeared from Solaris some time in
271 * early 2013, and has only reappeared recently in Solaris 11.2.
272 * Stop trying if we ever fail to read it, so we don't spam the log.
274 static int l2_size_avail = 1;
275 if (l2_size_avail && za_read_gauge(ksp, "l2_size", "cache_size", "L2") != 0)
279 za_read_derive(ksp, "deleted", "cache_operation", "deleted");
280 #if defined(KERNEL_FREEBSD)
281 za_read_derive(ksp, "allocated", "cache_operation", "allocated");
284 /* Issue indicators */
285 za_read_derive(ksp, "mutex_miss", "mutex_operations", "miss");
286 za_read_derive(ksp, "hash_collisions", "hash_collisions", "");
287 za_read_derive(ksp, "memory_throttle_count", "memory_throttle_count", "");
290 za_read_derive(ksp, "evict_l2_cached", "cache_eviction", "cached");
291 za_read_derive(ksp, "evict_l2_eligible", "cache_eviction", "eligible");
292 za_read_derive(ksp, "evict_l2_ineligible", "cache_eviction", "ineligible");
295 za_read_derive(ksp, "demand_data_hits", "cache_result", "demand_data-hit");
296 za_read_derive(ksp, "demand_metadata_hits", "cache_result",
297 "demand_metadata-hit");
298 za_read_derive(ksp, "prefetch_data_hits", "cache_result",
299 "prefetch_data-hit");
300 za_read_derive(ksp, "prefetch_metadata_hits", "cache_result",
301 "prefetch_metadata-hit");
302 za_read_derive(ksp, "demand_data_misses", "cache_result", "demand_data-miss");
303 za_read_derive(ksp, "demand_metadata_misses", "cache_result",
304 "demand_metadata-miss");
305 za_read_derive(ksp, "prefetch_data_misses", "cache_result",
306 "prefetch_data-miss");
307 za_read_derive(ksp, "prefetch_metadata_misses", "cache_result",
308 "prefetch_metadata-miss");
309 za_read_derive(ksp, "mfu_hits", "cache_result", "mfu-hit");
310 za_read_derive(ksp, "mfu_ghost_hits", "cache_result", "mfu_ghost-hit");
311 za_read_derive(ksp, "mru_hits", "cache_result", "mru-hit");
312 za_read_derive(ksp, "mru_ghost_hits", "cache_result", "mru_ghost-hit");
314 cdtime_t now = cdtime();
317 if ((value_to_rate(&arc_hits, (value_t){.derive = get_zfs_value(ksp, "hits")},
318 DS_TYPE_DERIVE, now, &arc_hits_state) == 0) &&
319 (value_to_rate(&arc_misses,
320 (value_t){.derive = get_zfs_value(ksp, "misses")},
321 DS_TYPE_DERIVE, now, &arc_misses_state) == 0)) {
322 za_submit_ratio("arc", arc_hits, arc_misses);
325 if ((value_to_rate(&l2_hits,
326 (value_t){.derive = get_zfs_value(ksp, "l2_hits")},
327 DS_TYPE_DERIVE, now, &l2_hits_state) == 0) &&
328 (value_to_rate(&l2_misses,
329 (value_t){.derive = get_zfs_value(ksp, "l2_misses")},
330 DS_TYPE_DERIVE, now, &l2_misses_state) == 0)) {
331 za_submit_ratio("L2", l2_hits, l2_misses);
336 {.derive = (derive_t)get_zfs_value(ksp, "l2_read_bytes")},
337 {.derive = (derive_t)get_zfs_value(ksp, "l2_write_bytes")},
339 za_submit("io_octets", "L2", l2_io, STATIC_ARRAY_SIZE(l2_io));
341 #if defined(KERNEL_LINUX)
342 free_zfs_values(ksp);
348 static int za_init(void) /* {{{ */
350 #if defined(KERNEL_SOLARIS)
351 /* kstats chain already opened by update_kstat (using *kc), verify everything
354 ERROR("zfs_arc plugin: kstat chain control structure not available.");
360 } /* }}} int za_init */
362 void module_register(void) {
363 plugin_register_init("zfs_arc", za_init);
364 plugin_register_read("zfs_arc", za_read);
365 } /* void module_register */
367 /* vmi: set sw=8 noexpandtab fdm=marker : */