1 /*
2  * blktrace output analysis: generate a timeline & gather statistics
3  *
4  * Copyright (C) 2006 Alan D. Brunelle <Alan.Brunelle@hp.com>
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, write to the Free Software
18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19  *
20  */
21 #include <float.h>
22 #include "globals.h"
23 
24 struct seek_bkt {
25 	struct rb_node rb_node;
26 	long long sectors;
27 	int nseeks;
28 };
29 
30 /* Seeks per second */
31 struct sps_bkt {
32 	double t_start, t_last;
33 	unsigned long nseeks;
34 };
35 
36 struct seeki {
37 	FILE *rfp, *wfp, *cfp, *sps_fp;
38 	struct rb_root root;
39 	struct sps_bkt sps;
40 	long long tot_seeks;
41 	double total_sectors;
42 	long long last_start, last_end;
43 };
44 
seek_open(char * str,char rw)45 static FILE *seek_open(char *str, char rw)
46 {
47 	FILE *fp;
48 	char *oname;
49 
50 	if (seek_name == NULL) return NULL;
51 
52 	oname = malloc(strlen(seek_name) + strlen(str) + 32);
53 	sprintf(oname, "%s_%s_%c.dat", seek_name, str, rw);
54 	if ((fp = my_fopen(oname, "w")) == NULL)
55 		perror(oname);
56 	else
57 		add_file(fp, oname);
58 
59 	return fp;
60 }
61 
__insert(struct rb_root * root,long long sectors)62 static void __insert(struct rb_root *root, long long sectors)
63 {
64 	struct seek_bkt *sbp;
65 	struct rb_node *parent = NULL;
66 	struct rb_node **p = &root->rb_node;
67 
68 	while (*p) {
69 		parent = *p;
70 		sbp = rb_entry(parent, struct seek_bkt, rb_node);
71 		if (sectors < sbp->sectors)
72 			p = &(*p)->rb_left;
73 		else if (sectors > sbp->sectors)
74 			p = &(*p)->rb_right;
75 		else {
76 			sbp->nseeks++;
77 			return;
78 		}
79 	}
80 
81 	sbp = malloc(sizeof(struct seek_bkt));
82 	sbp->nseeks = 1;
83 	sbp->sectors = sectors;
84 
85 	rb_link_node(&sbp->rb_node, parent, p);
86 	rb_insert_color(&sbp->rb_node, root);
87 }
88 
__destroy(struct rb_node * n)89 static void __destroy(struct rb_node *n)
90 {
91 	if (n) {
92 		struct seek_bkt *sbp = rb_entry(n, struct seek_bkt, rb_node);
93 
94 		__destroy(n->rb_left);
95 		__destroy(n->rb_right);
96 		free(sbp);
97 	}
98 }
99 
sps_emit(struct seeki * sip)100 static void sps_emit(struct seeki *sip)
101 {
102 	double tstamp, s_p_s;
103 	struct sps_bkt *sps = &sip->sps;
104 	double delta = sps->t_last - sps->t_start;
105 
106 	if ((sps->nseeks == 1) || (delta < DBL_EPSILON)) {
107 		s_p_s = (double)(sps->nseeks);
108 		tstamp = sps->t_start;
109 	} else {
110 
111 		s_p_s = (double)(sps->nseeks) / delta;
112 		tstamp = sps->t_start + (delta / 2);
113 	}
114 
115 	fprintf(sip->sps_fp, "%15.9lf %.2lf\n", sps->t_start, s_p_s);
116 
117 	sps->t_start = 0;
118 	sps->nseeks = 0;
119 }
120 
sps_add(struct seeki * sip,double t)121 static void sps_add(struct seeki *sip, double t)
122 {
123 	if (sip->sps_fp) {
124 		struct sps_bkt *sps = &sip->sps;
125 
126 		if (sps->nseeks != 0 && ((t - sps->t_start) >= 1.0))
127 			sps_emit(sip);
128 
129 		sps->t_last = t;
130 		if (sps->nseeks == 0) {
131 			sps->t_start = t;
132 			sps->nseeks = 1;
133 		} else
134 			sps->nseeks++;
135 	}
136 }
137 
__median(struct rb_node * n,long long sofar,long long target,long long * rvp)138 static int __median(struct rb_node *n, long long sofar, long long target,
139 		    long long *rvp)
140 {
141 	struct seek_bkt *sbp;
142 
143 	sbp = rb_entry(n, struct seek_bkt, rb_node);
144 	if ((sofar + sbp->nseeks) >= target) {
145 		*rvp = sbp->sectors;
146 		return 1;
147 	}
148 
149 	if (n->rb_left && __median(n->rb_left, sofar, target, rvp))
150 		return 1;
151 
152 	if (n->rb_right && __median(n->rb_right, sofar, target, rvp))
153 		return 1;
154 
155 	return 0;
156 
157 }
158 
__mode(struct rb_node * n,struct mode * mp)159 static void __mode(struct rb_node *n, struct mode *mp)
160 {
161 	struct seek_bkt *sbp;
162 
163 	if (n->rb_left)
164 		__mode(n->rb_left, mp);
165 	if (n->rb_right)
166 		__mode(n->rb_right, mp);
167 
168 	sbp = rb_entry(n, struct seek_bkt, rb_node);
169 	if (mp->modes == NULL) {
170 		mp->modes = malloc(sizeof(long long));
171 		mp->nmds = 0;
172 	} else if (sbp->nseeks > mp->most_seeks)
173 		mp->nmds = 0;
174 	else if (sbp->nseeks == mp->most_seeks)
175 		mp->modes = realloc(mp->modes, (mp->nmds + 1) *
176 							sizeof(long long));
177 	else
178 		return;
179 
180 	mp->most_seeks = sbp->nseeks;
181 	mp->modes[mp->nmds++] = sbp->sectors;
182 }
183 
seek_dist(struct seeki * sip,struct io * iop)184 long long seek_dist(struct seeki *sip, struct io *iop)
185 {
186 	long long dist;
187 	long long start = BIT_START(iop), end = BIT_END(iop);
188 
189 	if (seek_absolute)
190 		dist = start - sip->last_end;
191 	else {
192 		/* Some overlap means no seek */
193 		if (((sip->last_start <= start) && (start <= sip->last_end)) ||
194 		    ((sip->last_start <= end) && (end <= sip->last_end)))
195 			dist = 0;
196 		else if (start > sip->last_end)
197 			dist = start - sip->last_end;
198 		else
199 			dist = start - sip->last_start;
200 
201 	}
202 
203 	sip->last_start = start;
204 	sip->last_end = end;
205 	return dist;
206 }
207 
seeki_alloc(char * str)208 void *seeki_alloc(char *str)
209 {
210 	struct seeki *sip = malloc(sizeof(struct seeki));
211 
212 	sip->rfp = seek_open(str, 'r');
213 	sip->wfp = seek_open(str, 'w');
214 	sip->cfp = seek_open(str, 'c');
215 	sip->tot_seeks = 0;
216 	sip->total_sectors = 0.0;
217 	sip->last_start = sip->last_end = 0;
218 	memset(&sip->root, 0, sizeof(sip->root));
219 
220 	if (sps_name) {
221 		char *oname;
222 
223 		memset(&sip->sps, 0, sizeof(sip->sps));
224 
225 		oname = malloc(strlen(sps_name) + strlen(str) + 32);
226 		sprintf(oname, "%s_%s.dat", sps_name, str);
227 		if ((sip->sps_fp = my_fopen(oname, "w")) == NULL)
228 			perror(oname);
229 		else
230 			add_file(sip->sps_fp, oname);
231 	} else
232 		sip->sps_fp = NULL;
233 
234 	return sip;
235 }
236 
seeki_free(void * param)237 void seeki_free(void *param)
238 {
239 	struct seeki *sip = param;
240 
241 	if (sip->sps_fp && sip->sps.nseeks != 0)
242 		sps_emit(sip);
243 
244 	/*
245 	 * Associated files are cleaned up by seek_clean
246 	 */
247 	__destroy(sip->root.rb_node);
248 	free(sip);
249 }
250 
seeki_add(void * handle,struct io * iop)251 void seeki_add(void *handle, struct io *iop)
252 {
253 	struct seeki *sip = handle;
254 	char rw = IOP_READ(iop) ? 'r' : 'w';
255 	long long dist = seek_dist(sip, iop);
256 	double tstamp = BIT_TIME(iop->t.time);
257 	FILE *fp = IOP_READ(iop) ? sip->rfp : sip->wfp;
258 
259 	if (fp)
260 		fprintf(fp, "%15.9lf %13lld %c\n", tstamp, dist, rw);
261 	if (sip->cfp)
262 		fprintf(sip->cfp, "%15.9lf %13lld %c\n", tstamp, dist, rw);
263 
264 	dist = llabs(dist);
265 	sip->tot_seeks++;
266 	sip->total_sectors += dist;
267 	__insert(&sip->root, dist);
268 
269 	sps_add(sip, tstamp);
270 }
271 
seeki_nseeks(void * handle)272 long long seeki_nseeks(void *handle)
273 {
274 	return ((struct seeki *)handle)->tot_seeks;
275 }
276 
seeki_mean(void * handle)277 double seeki_mean(void *handle)
278 {
279 	struct seeki *sip = handle;
280 	return sip->total_sectors / sip->tot_seeks;
281 }
282 
seeki_median(void * handle)283 long long seeki_median(void *handle)
284 {
285 	long long rval = 0LL;
286 	struct seeki *sip = handle;
287 
288 	if (sip->root.rb_node)
289 		(void)__median(sip->root.rb_node, 0LL, sip->tot_seeks / 2,
290 			       &rval);
291 
292 	return rval;
293 }
294 
seeki_mode(void * handle,struct mode * mp)295 int seeki_mode(void *handle, struct mode *mp)
296 {
297 	struct seeki *sip = handle;
298 	struct rb_root *root = &sip->root;
299 
300 	memset(mp, 0, sizeof(struct mode));
301 	if (root->rb_node)
302 		__mode(root->rb_node, mp);
303 
304 	return mp->nmds;
305 }
306