xref: /illumos-gate/usr/src/cmd/pools/poolstat/sa_kstat.c (revision 86d949f9497332fe19be6b5d711d265eb957439f)
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 /*
28  * sa_kstat - kstat statistic adapter, collects statistic data provided
29  * by kstat.
30  */
31 
32 #include <locale.h>
33 #include <string.h>
34 #include <assert.h>
35 #include <kstat.h>
36 #include <pool.h>
37 #include "utils.h"
38 #include <sys/pset.h>
39 #include "poolstat.h"
40 #include "poolstat_utils.h"
41 
42 /* marks 'sdata_t' element as updated	*/
43 #define	SD_UPDATED	1
44 
45 /* Specified value for an invalid set.	*/
46 #define	INVALID_SET	-2
47 
48 /* statistic data	*/
49 typedef struct sdata {
50 	kstat_t		sd_oks;		/* old kstat	*/
51 	kstat_t		sd_nks;		/* new kstat	*/
52 	void		*sd_udata; 	/* user data	*/
53 	uint_t		sd_state;	/* state of this data (UPDATED)	*/
54 	struct sdata	*sd_next;
55 } sdata_t;
56 
57 /* pset user data	*/
58 typedef struct {
59 	psetid_t opset;		/* old pset sysid	*/
60 	psetid_t npset;		/* new pset sysid	*/
61 } pset_ud_t;
62 
63 /* shortcuts to access set's id in 'pset_ud_t'		*/
64 #define	SD_OPSET(p)	(((pset_ud_t *)(p)->sd_udata)->opset)
65 #define	SD_NPSET(p)	(((pset_ud_t *)(p)->sd_udata)->npset)
66 
67 static	kstat_ctl_t	*ks_ctl;	/* libkstat handle		*/
68 static  sdata_t		*cpu_list;	/* list with cpu statistics	*/
69 
70 static sdata_t *update_sdata_list(sdata_t *, kstat_ctl_t *, char *, int,
71 	char *, int *);
72 static void update_cpu_list(sdata_t *list);
73 static void update_pset_stats(statistic_bag_t *, sdata_t *);
74 
75 /*ARGSUSED*/
76 void
77 sa_kstat_init(void *unused)
78 {
79 	if ((ks_ctl = kstat_open()) == NULL)
80 		die(gettext(ERR_KSTAT_OPEN), get_errstr());
81 }
82 
83 void
84 sa_kstat_update(statistic_bag_t *sbag, int flags)
85 {
86 	/* The SA_REFRESH flag forces the update of local data structures. */
87 	if (flags & SA_REFRESH) {
88 		int	ks_error = 0;
89 
90 		if (kstat_chain_update(ks_ctl) == -1)
91 			die(gettext(ERR_KSTAT_DATA), get_errstr());
92 		cpu_list = update_sdata_list(cpu_list, ks_ctl, "cpu",
93 							-1, "sys", &ks_error);
94 		if (ks_error)
95 			die(gettext(ERR_KSTAT_DATA), get_errstr());
96 
97 		/* update info about cpu binding to processor sets	*/
98 		update_cpu_list(cpu_list);
99 	}
100 
101 	if (strcmp(sbag->sb_type, PSET_TYPE_NAME) == 0) {
102 		update_pset_stats(sbag, cpu_list);
103 	} else if (strcmp(sbag->sb_type, POOL_TYPE_NAME) == 0) {
104 		return;
105 	} else {
106 		die(gettext(ERR_UNSUPP_STYPE), sbag->sb_type);
107 	}
108 
109 }
110 
111 static void *
112 safe_kstat_data_lookup(kstat_t *ksp, char *name)
113 {
114 	void *dp;
115 
116 	if ((dp = kstat_data_lookup(ksp, name)) == NULL)
117 		die(gettext(ERR_KSTAT_DLOOKUP),
118 			ksp->ks_name, name, get_errstr());
119 
120 	return (dp);
121 }
122 
123 /*
124  * Find the delta over the interval between new_ksp and old_ksp.
125  * If old_ksp->ks_data is NULL and 'oz' is set then pretend
126  * that old_ksp is zero otherwise return 0.
127  */
128 static uint64_t
129 delta(kstat_t *new_ksp, kstat_t *old_ksp, char *name, int oz)
130 {
131 	kstat_named_t *new_ksn;
132 	kstat_named_t *old_ksn;
133 
134 	new_ksn = (kstat_named_t *)safe_kstat_data_lookup(new_ksp, name);
135 	if (old_ksp == NULL || old_ksp->ks_data == NULL)
136 		return ((oz == 1) ? new_ksn->value.ui64 : 0);
137 	old_ksn = (kstat_named_t *)safe_kstat_data_lookup(old_ksp, name);
138 
139 	return (new_ksn->value.ui64 - old_ksn->value.ui64);
140 }
141 
142 /*
143  * Create a clone of the passed kstat_t structure 'kstat_t'. If
144  * 'fr' flag is set free the old ks_data structure in 'dst'.
145  */
146 static void
147 kstat_clone(kstat_t *src, kstat_t *dst, int fr)
148 {
149 	if (fr)
150 		FREE(dst->ks_data);
151 	*dst = *src;
152 	if (src->ks_data != NULL) {
153 		dst->ks_data = ZALLOC(src->ks_data_size);
154 		(void) memcpy(dst->ks_data, src->ks_data, src->ks_data_size);
155 	} else {
156 		dst->ks_data = NULL;
157 		dst->ks_data_size = 0;
158 	}
159 }
160 
161 /*
162  * Erase the data from 'src'.
163  */
164 static void
165 kstat_erase(kstat_t *src)
166 {
167 	FREE(src->ks_data);
168 	(void) memset(src, 0, sizeof (*src));
169 }
170 
171 /*
172  * Create a new statistic data object with its own copy of the passed
173  * kstat.
174  */
175 static sdata_t *
176 sdata_new(kstat_t *ksp)
177 {
178 	sdata_t *sdp;
179 
180 	NEW0(sdp);
181 	kstat_clone(ksp, &sdp->sd_nks, 0);
182 
183 	return (sdp);
184 }
185 
186 static void
187 sdata_free(sdata_t *sdp)
188 {
189 	FREE(sdp->sd_oks.ks_data);
190 	FREE(sdp->sd_nks.ks_data);
191 	FREE(sdp->sd_udata);
192 	FREE(sdp);
193 }
194 
195 /*
196  * Create new or update an existing list of cpu statistics. For each
197  * cpu two kstats are kept. One old kstat which contains the data from
198  * the previous scan, and new with the current data. The old and the new
199  * kstats *must* be for the same instance and have the same kid.
200  * If 'instance' argument is set to -1 don't use it as a filter.
201  */
202 static sdata_t *
203 update_sdata_list(sdata_t *list, kstat_ctl_t *kc, char *module,
204 		int instance, char *name, int *errp)
205 {
206 	kstat_t *ksp;
207 	sdata_t	*sdp, *sdpp; /* kstat instance pointer/previous-pointer */
208 
209 	for (ksp = kc->kc_chain; ksp; ksp = ksp->ks_next) {
210 		if (strcmp(ksp->ks_module, module) == 0 &&
211 			(name == NULL || strcmp(ksp->ks_name, name) == 0) &&
212 			(instance == -1 || ksp->ks_instance == instance)) {
213 			if (kstat_read(kc, ksp, NULL) == -1) {
214 				*errp = -1;
215 				return (list);
216 			}
217 			/*
218 			 * Find the kstat in the existing list:
219 			 * If we find one for the same instance and with the
220 			 * same ks_kid we'll save it as old_kstat.
221 			 * If we find one for the same instance but with a
222 			 * different ks_kid we'll removed it.
223 			 */
224 			for (sdpp = sdp = list; sdp; sdp = sdp->sd_next) {
225 				if (ksp->ks_instance ==
226 						sdp->sd_nks.ks_instance) {
227 					if (ksp->ks_kid == sdp->sd_nks.ks_kid) {
228 						kstat_clone(&sdp->sd_nks,
229 							&sdp->sd_oks, 1);
230 					} else {
231 						kstat_erase(&sdp->sd_oks);
232 					}
233 					kstat_clone(ksp, &sdp->sd_nks, 1);
234 					sdp->sd_state |= SD_UPDATED;
235 					break;
236 				}
237 				sdpp = sdp;
238 			}
239 			/* add a new kstat instance	*/
240 			if (!sdp) {
241 				/* first instance	*/
242 				if (!list) {
243 					list = sdata_new(ksp);
244 					list->sd_state |= SD_UPDATED;
245 				} else {
246 					sdpp->sd_next = sdata_new(ksp);
247 					sdpp->sd_next->sd_state |= SD_UPDATED;
248 				}
249 			}
250 		}
251 	}
252 
253 	/* remove untouched statistics	*/
254 	sdp = list;
255 	sdpp = NULL;
256 	while (sdp != NULL) {
257 
258 		if (sdp->sd_state & SD_UPDATED) {
259 			sdp->sd_state &= ~SD_UPDATED;
260 			sdpp = sdp;
261 			sdp = sdp->sd_next;
262 		} else {
263 			sdata_t *tmp;
264 
265 			if (sdpp == NULL)
266 				list = sdp->sd_next;
267 			else
268 				sdpp->sd_next = sdp->sd_next;
269 			tmp = sdp->sd_next;
270 			sdata_free(sdp);
271 			sdp = tmp;
272 		}
273 	}
274 
275 	*errp = 0;
276 	return (list);
277 }
278 
279 /*
280  * Update the pset assignment information for each cpu in the statistic
281  * data list.
282  */
283 static void
284 update_cpu_list(sdata_t *list)
285 {
286 	sdata_t	*sdp;
287 
288 	for (sdp = list; sdp; sdp = sdp->sd_next) {
289 		/* for new CPU create a new user data object	*/
290 		if (sdp->sd_udata == NULL) {
291 			sdp->sd_udata = ZALLOC(sizeof (pset_ud_t));
292 			/*
293 			 * set its pset to invalid, so it will not be
294 			 * used in statistics calculation.
295 			 */
296 			SD_NPSET(sdp) = INVALID_SET;
297 		}
298 		/* copy the pset assignment information to the previous stat */
299 		SD_OPSET(sdp) = SD_NPSET(sdp);
300 		/* set the current assignment	*/
301 		if (pset_assign(PS_QUERY, sdp->sd_nks.ks_instance,
302 			&(SD_NPSET(sdp))) == -1)
303 			SD_NPSET(sdp) = INVALID_SET;
304 	}
305 }
306 
307 /*
308  * Update statistic data for pset. Calculate the CPU usage in a pset.
309  */
310 static void
311 update_pset_stats(statistic_bag_t *sbag, sdata_t *list)
312 {
313 	sdata_t	*sdp;
314 	pset_statistic_bag_t *bag = (pset_statistic_bag_t *)sbag->bag;
315 	uint64_t allticks, ust, kst, ist, wst;
316 
317 	ust = kst = ist = wst = 0;
318 	for (sdp = list; sdp; sdp = sdp->sd_next) {
319 		/*
320 		 * only calculate for the asked pset id and if the cpu belongs
321 		 * to the same set in the previous and in the current snapshot.
322 		 * It means that the usage for CPUs that were rebound during
323 		 * the sampling interval are not charged to any set.
324 		 */
325 		if ((SD_OPSET(sdp) == SD_NPSET(sdp)) &&
326 			(SD_NPSET(sdp) == bag->pset_sb_sysid)) {
327 			ust += delta(&sdp->sd_nks, &sdp->sd_oks,
328 				"cpu_ticks_user", 0);
329 			kst += delta(&sdp->sd_nks, &sdp->sd_oks,
330 				"cpu_ticks_kernel", 0);
331 			ist += delta(&sdp->sd_nks, &sdp->sd_oks,
332 				"cpu_ticks_idle", 0);
333 			wst += delta(&sdp->sd_nks, &sdp->sd_oks,
334 				"cpu_ticks_wait", 0);
335 		}
336 	}
337 
338 	if ((allticks = ust + kst + wst + ist) != 0) {
339 		bag->pset_sb_used =
340 			(double)(ust + kst) / allticks * bag->pset_sb_size;
341 	} else {
342 		bag->pset_sb_used = 0.0;
343 	}
344 }
345