xref: /illumos-gate/usr/src/cmd/pools/poolstat/sa_kstat.c (revision 8d483882aa3390058094b043f3d62187b5d1de03)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * sa_kstat - kstat statistic adapter, collects statistic data provided
31  * by kstat.
32  */
33 
34 #include <locale.h>
35 #include <string.h>
36 #include <assert.h>
37 #include <kstat.h>
38 #include <pool.h>
39 #include "utils.h"
40 #include <sys/pset.h>
41 #include "poolstat.h"
42 #include "poolstat_utils.h"
43 
44 /* marks 'sdata_t' element as updated	*/
45 #define	SD_UPDATED	1
46 
47 /* Specified value for an invalid set.	*/
48 #define	INVALID_SET	-2
49 
50 /* statistic data	*/
51 typedef struct sdata {
52 	kstat_t		sd_oks;		/* old kstat	*/
53 	kstat_t		sd_nks;		/* new kstat	*/
54 	void		*sd_udata; 	/* user data	*/
55 	uint_t		sd_state;	/* state of this data (UPDATED)	*/
56 	struct sdata	*sd_next;
57 } sdata_t;
58 
59 /* pset user data	*/
60 typedef struct {
61 	psetid_t opset;		/* old pset sysid	*/
62 	psetid_t npset;		/* new pset sysid	*/
63 } pset_ud_t;
64 
65 /* shortcuts to access set's id in 'pset_ud_t'		*/
66 #define	SD_OPSET(p)	(((pset_ud_t *)(p)->sd_udata)->opset)
67 #define	SD_NPSET(p)	(((pset_ud_t *)(p)->sd_udata)->npset)
68 
69 static	kstat_ctl_t	*ks_ctl;	/* libkstat handle		*/
70 static  sdata_t		*cpu_list;	/* list with cpu statistics	*/
71 
72 static sdata_t *update_sdata_list(sdata_t *, kstat_ctl_t *, char *, int,
73 	char *, int *);
74 static void update_cpu_list(sdata_t *list);
75 static void update_pset_stats(statistic_bag_t *, sdata_t *);
76 
77 /*ARGSUSED*/
78 void
79 sa_kstat_init(void *unused)
80 {
81 	if ((ks_ctl = kstat_open()) == NULL)
82 		die(gettext(ERR_KSTAT_OPEN), get_errstr());
83 }
84 
85 void
86 sa_kstat_update(statistic_bag_t *sbag, int flags)
87 {
88 	/* The SA_REFRESH flag forces the update of local data structures. */
89 	if (flags & SA_REFRESH) {
90 		int	ks_error = 0;
91 
92 		if (kstat_chain_update(ks_ctl) == -1)
93 			die(gettext(ERR_KSTAT_DATA), get_errstr());
94 		cpu_list = update_sdata_list(cpu_list, ks_ctl, "cpu",
95 							-1, "sys", &ks_error);
96 		if (ks_error)
97 			die(gettext(ERR_KSTAT_DATA), get_errstr());
98 
99 		/* update info about cpu binding to processor sets	*/
100 		update_cpu_list(cpu_list);
101 	}
102 
103 	if (strcmp(sbag->sb_type, PSET_TYPE_NAME) == 0) {
104 		update_pset_stats(sbag, cpu_list);
105 	} else if (strcmp(sbag->sb_type, POOL_TYPE_NAME) == 0) {
106 		return;
107 	} else {
108 		die(gettext(ERR_UNSUPP_STYPE), sbag->sb_type);
109 	}
110 
111 }
112 
113 static void *
114 safe_kstat_data_lookup(kstat_t *ksp, char *name)
115 {
116 	void *dp;
117 
118 	if ((dp = kstat_data_lookup(ksp, name)) == NULL)
119 		die(gettext(ERR_KSTAT_DLOOKUP),
120 			ksp->ks_name, name, get_errstr());
121 
122 	return (dp);
123 }
124 
125 /*
126  * Find the delta over the interval between new_ksp and old_ksp.
127  * If old_ksp->ks_data is NULL and 'oz' is set then pretend
128  * that old_ksp is zero otherwise return 0.
129  */
130 static uint64_t
131 delta(kstat_t *new_ksp, kstat_t *old_ksp, char *name, int oz)
132 {
133 	kstat_named_t *new_ksn;
134 	kstat_named_t *old_ksn;
135 
136 	new_ksn = (kstat_named_t *)safe_kstat_data_lookup(new_ksp, name);
137 	if (old_ksp == NULL || old_ksp->ks_data == NULL)
138 		return ((oz == 1) ? new_ksn->value.ui64 : 0);
139 	old_ksn = (kstat_named_t *)safe_kstat_data_lookup(old_ksp, name);
140 
141 	return (new_ksn->value.ui64 - old_ksn->value.ui64);
142 }
143 
144 /*
145  * Create a clone of the passed kstat_t structure 'kstat_t'. If
146  * 'fr' flag is set free the old ks_data structure in 'dst'.
147  */
148 static void
149 kstat_clone(kstat_t *src, kstat_t *dst, int fr)
150 {
151 	if (fr)
152 		FREE(dst->ks_data);
153 	*dst = *src;
154 	if (src->ks_data != NULL) {
155 		dst->ks_data = ZALLOC(src->ks_data_size);
156 		(void) memcpy(dst->ks_data, src->ks_data, src->ks_data_size);
157 	} else {
158 		dst->ks_data = NULL;
159 		dst->ks_data_size = 0;
160 	}
161 }
162 
163 /*
164  * Erase the data from 'src'.
165  */
166 static void
167 kstat_erase(kstat_t *src)
168 {
169 	FREE(src->ks_data);
170 	(void) memset(src, 0, sizeof (*src));
171 }
172 
173 /*
174  * Create a new statistic data object with its own copy of the passed
175  * kstat.
176  */
177 static sdata_t *
178 sdata_new(kstat_t *ksp)
179 {
180 	sdata_t *sdp;
181 
182 	NEW0(sdp);
183 	kstat_clone(ksp, &sdp->sd_nks, 0);
184 
185 	return (sdp);
186 }
187 
188 static void
189 sdata_free(sdata_t *sdp)
190 {
191 	FREE(sdp->sd_oks.ks_data);
192 	FREE(sdp->sd_nks.ks_data);
193 	FREE(sdp->sd_udata);
194 	FREE(sdp);
195 }
196 
197 /*
198  * Create new or update an existing list of cpu statistics. For each
199  * cpu two kstats are kept. One old kstat which contains the data from
200  * the previous scan, and new with the current data. The old and the new
201  * kstats *must* be for the same instance and have the same kid.
202  * If 'instance' argument is set to -1 don't use it as a filter.
203  */
204 static sdata_t *
205 update_sdata_list(sdata_t *list, kstat_ctl_t *kc, char *module,
206 		int instance, char *name, int *errp)
207 {
208 	kstat_t *ksp;
209 	sdata_t	*sdp, *sdpp; /* kstat instance pointer/previous-pointer */
210 
211 	for (ksp = kc->kc_chain; ksp; ksp = ksp->ks_next) {
212 		if (strcmp(ksp->ks_module, module) == 0 &&
213 			(name == NULL || strcmp(ksp->ks_name, name) == 0) &&
214 			(instance == -1 || ksp->ks_instance == instance)) {
215 			if (kstat_read(kc, ksp, NULL) == -1) {
216 				*errp = -1;
217 				return (list);
218 			}
219 			/*
220 			 * Find the kstat in the existing list:
221 			 * If we find one for the same instance and with the
222 			 * same ks_kid we'll save it as old_kstat.
223 			 * If we find one for the same instance but with a
224 			 * different ks_kid we'll removed it.
225 			 */
226 			for (sdpp = sdp = list; sdp; sdp = sdp->sd_next) {
227 				if (ksp->ks_instance ==
228 						sdp->sd_nks.ks_instance) {
229 					if (ksp->ks_kid == sdp->sd_nks.ks_kid) {
230 						kstat_clone(&sdp->sd_nks,
231 							&sdp->sd_oks, 1);
232 					} else {
233 						kstat_erase(&sdp->sd_oks);
234 					}
235 					kstat_clone(ksp, &sdp->sd_nks, 1);
236 					sdp->sd_state |= SD_UPDATED;
237 					break;
238 				}
239 				sdpp = sdp;
240 			}
241 			/* add a new kstat instance	*/
242 			if (!sdp) {
243 				/* first instance	*/
244 				if (!list) {
245 					list = sdata_new(ksp);
246 					list->sd_state |= SD_UPDATED;
247 				} else {
248 					sdpp->sd_next = sdata_new(ksp);
249 					sdpp->sd_next->sd_state |= SD_UPDATED;
250 				}
251 			}
252 		}
253 	}
254 
255 	/* remove untouched statistics	*/
256 	sdp = list;
257 	sdpp = NULL;
258 	while (sdp != NULL) {
259 
260 		if (sdp->sd_state & SD_UPDATED) {
261 			sdp->sd_state &= ~SD_UPDATED;
262 			sdpp = sdp;
263 			sdp = sdp->sd_next;
264 		} else {
265 			sdata_t *tmp;
266 
267 			if (sdpp == NULL)
268 				list = sdp->sd_next;
269 			else
270 				sdpp->sd_next = sdp->sd_next;
271 			tmp = sdp->sd_next;
272 			sdata_free(sdp);
273 			sdp = tmp;
274 		}
275 	}
276 
277 	*errp = 0;
278 	return (list);
279 }
280 
281 /*
282  * Update the pset assignment information for each cpu in the statistic
283  * data list.
284  */
285 static void
286 update_cpu_list(sdata_t *list)
287 {
288 	sdata_t	*sdp;
289 
290 	for (sdp = list; sdp; sdp = sdp->sd_next) {
291 		/* for new CPU create a new user data object	*/
292 		if (sdp->sd_udata == NULL) {
293 			sdp->sd_udata = ZALLOC(sizeof (pset_ud_t));
294 			/*
295 			 * set its pset to invalid, so it will not be
296 			 * used in statistics calculation.
297 			 */
298 			SD_NPSET(sdp) = INVALID_SET;
299 		}
300 		/* copy the pset assignment information to the previous stat */
301 		SD_OPSET(sdp) = SD_NPSET(sdp);
302 		/* set the current assignment	*/
303 		if (pset_assign(PS_QUERY, sdp->sd_nks.ks_instance,
304 			&(SD_NPSET(sdp))) == -1)
305 			SD_NPSET(sdp) = INVALID_SET;
306 	}
307 }
308 
309 /*
310  * Update statistic data for pset. Calculate the CPU usage in a pset.
311  */
312 static void
313 update_pset_stats(statistic_bag_t *sbag, sdata_t *list)
314 {
315 	sdata_t	*sdp;
316 	pset_statistic_bag_t *bag = (pset_statistic_bag_t *)sbag->bag;
317 	uint64_t allticks, ust, kst, ist, wst;
318 
319 	ust = kst = ist = wst = 0;
320 	for (sdp = list; sdp; sdp = sdp->sd_next) {
321 		/*
322 		 * only calculate for the asked pset id and if the cpu belongs
323 		 * to the same set in the previous and in the current snapshot.
324 		 * It means that the usage for CPUs that were rebound during
325 		 * the sampling interval are not charged to any set.
326 		 */
327 		if ((SD_OPSET(sdp) == SD_NPSET(sdp)) &&
328 			(SD_NPSET(sdp) == bag->pset_sb_sysid)) {
329 			ust += delta(&sdp->sd_nks, &sdp->sd_oks,
330 				"cpu_ticks_user", 0);
331 			kst += delta(&sdp->sd_nks, &sdp->sd_oks,
332 				"cpu_ticks_kernel", 0);
333 			ist += delta(&sdp->sd_nks, &sdp->sd_oks,
334 				"cpu_ticks_idle", 0);
335 			wst += delta(&sdp->sd_nks, &sdp->sd_oks,
336 				"cpu_ticks_wait", 0);
337 		}
338 	}
339 
340 	if ((allticks = ust + kst + wst + ist) != 0) {
341 		bag->pset_sb_used =
342 			(double)(ust + kst) / allticks * bag->pset_sb_size;
343 	} else {
344 		bag->pset_sb_used = 0.0;
345 	}
346 }
347