1 /*
2 * Copyright IBM Corp. 2008
3 *
4 * Author(s): Martin Peschke <mp3@de.ibm.com>
5 * Stefan Raspl <stefan.raspl@de.ibm.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22 #ifndef STATS_H
23 #define STATS_H
24
25 #include <linux/types.h>
26 #include "blktrace.h"
27
28 struct minmax {
29 __u64 min;
30 __u64 max;
31 __u64 sum;
32 __u64 sos;
33 __u64 num;
34 };
35
minmax_init(struct minmax * mm)36 static inline void minmax_init(struct minmax *mm)
37 {
38 mm->min = -1ULL;
39 mm->max = 0;
40 mm->sum = 0;
41 mm->sos = 0;
42 mm->num = 0;
43 }
44
minmax_account(struct minmax * mm,__u64 value)45 static inline void minmax_account(struct minmax *mm, __u64 value)
46 {
47 mm->sum += value;
48 mm->sos += value * value;
49 if (value < mm->min)
50 mm->min = value;
51 if (value > mm->max)
52 mm->max = value;
53 mm->num++;
54 }
55
minmax_merge(struct minmax * dst,struct minmax * src)56 static inline void minmax_merge(struct minmax *dst, struct minmax *src)
57 {
58 dst->sum += src->sum;
59 dst->sos += src->sos;
60 if (src->min < dst->min)
61 dst->min = src->min;
62 if (src->max > dst->max)
63 dst->max = src->max;
64 dst->num += src->num;
65 }
66
minmax_to_be(struct minmax * mm)67 static inline void minmax_to_be(struct minmax *mm)
68 {
69 mm->sum = cpu_to_be64(mm->sum);
70 mm->sos = cpu_to_be64(mm->sos);
71 mm->min = cpu_to_be64(mm->min);
72 mm->max = cpu_to_be64(mm->max);
73 mm->num = cpu_to_be64(mm->num);
74 }
75
minmax_avg(struct minmax * mm)76 static inline double minmax_avg(struct minmax *mm)
77 {
78 if (!mm->num)
79 return 0;
80
81 return (mm->sum / (double)mm->num);
82 }
83
minmax_var(struct minmax * mm)84 static inline double minmax_var(struct minmax *mm)
85 {
86 double num = (double)mm->num;
87
88 if (!mm->num)
89 return 0;
90
91 return ((mm->sos - ((mm->sum * mm->sum) / num)) / num);
92 }
93
minmax_print(FILE * fp,const char * s,struct minmax * mm)94 static inline int minmax_print(FILE *fp, const char *s, struct minmax *mm)
95 {
96 return fprintf(fp, "%s: num %Ld, min %Ld, max %Ld, sum %Ld, squ %Ld, "
97 "avg %.1f, var %.1f\n", s, (unsigned long long)mm->num,
98 (unsigned long long)mm->min, (unsigned long long)mm->max,
99 (unsigned long long)mm->sum, (unsigned long long)mm->sos,
100 minmax_avg(mm), minmax_var(mm));
101 }
102
103 struct histlog2 {
104 int first;
105 int delta;
106 int num;
107 };
108
histlog2_upper_limit(int index,struct histlog2 * h)109 static inline __u64 histlog2_upper_limit(int index, struct histlog2 *h)
110 {
111 return h->first + (index ? h->delta << (index - 1) : 0);
112 }
113
histlog2_index(__u64 val,struct histlog2 * h)114 static inline int histlog2_index(__u64 val, struct histlog2 *h)
115 {
116 int i;
117
118 for (i = 0; i < (h->num - 1) && val > histlog2_upper_limit(i, h); i++);
119 return i;
120 }
121
histlog2_account(__u32 * bucket,__u32 val,struct histlog2 * h)122 static inline void histlog2_account(__u32 *bucket, __u32 val,
123 struct histlog2 *h)
124 {
125 int index = histlog2_index(val, h);
126 bucket[index]++;
127 }
128
histlog2_merge(struct histlog2 * h,__u32 * dst,__u32 * src)129 static inline void histlog2_merge(struct histlog2 *h, __u32 *dst, __u32 *src)
130 {
131 int i;
132
133 for (i = 0; i < h->num; i++)
134 dst[i] += src[i];
135 }
136
histlog2_to_be(__u32 a[],struct histlog2 * h)137 static inline void histlog2_to_be(__u32 a[], struct histlog2 *h)
138 {
139 int i;
140
141 for (i = 0; i < h->num; i++)
142 a[i] = cpu_to_be32(a[i]);
143 }
144
histlog2_print(FILE * fp,const char * s,__u32 a[],struct histlog2 * h)145 static inline void histlog2_print(FILE *fp, const char *s, __u32 a[],
146 struct histlog2 *h)
147 {
148 int i;
149
150 fprintf(fp, "%s:\n", s);
151 for (i = 0; i < h->num - 1; i++) {
152 fprintf(fp, " %10ld:%6d",
153 (unsigned long)(histlog2_upper_limit(i, h)), a[i]);
154 if (!((i + 1) % 4))
155 fprintf(fp, "\n");
156 }
157 fprintf(fp, " >%8ld:%6d\n",
158 (unsigned long)(histlog2_upper_limit(i - 1, h)), a[i]);
159 }
160
161 #endif
162