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      1 /*
      2  * blktrace output analysis: generate a timeline & gather statistics
      3  *
      4  * Copyright (C) 2006 Alan D. Brunelle <Alan.Brunelle (at) 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 
     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 
     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 
     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 
    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 
    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 
    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 
    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 
    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 
    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 
    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 
    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 
    272 long long seeki_nseeks(void *handle)
    273 {
    274 	return ((struct seeki *)handle)->tot_seeks;
    275 }
    276 
    277 double seeki_mean(void *handle)
    278 {
    279 	struct seeki *sip = handle;
    280 	return sip->total_sectors / sip->tot_seeks;
    281 }
    282 
    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 
    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