minix/commands/sprofdiff/sprofdiff.c

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#include <assert.h>
#include <errno.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "tdist.h"
/* user-configurable settings */
#define DEBUG 0
#define PROC_NAME_WIDTH 10
#define SYMBOL_NAME_WIDTH 24
/* types */
#define SYMBOL_HASHTAB_SIZE 1024
#define SYMBOL_NAME_SIZE 52
struct symbol_count {
unsigned long sum;
unsigned long long sum2;
unsigned long min;
unsigned long max;
};
enum symbol_class {
sc_total,
sc_idle,
sc_system,
sc_user,
sc_process,
sc_symbol
};
struct symbol_info {
struct symbol_info *next;
struct symbol_info *hashtab_next;
char binary[PROC_NAME_LEN];
char name[SYMBOL_NAME_SIZE];
struct symbol_count count[2];
long diff;
enum symbol_class class;
};
/* global variables */
static unsigned n1, n2;
static struct symbol_info *symbols;
static struct symbol_info *symbol_hashtab[SYMBOL_HASHTAB_SIZE];
/* prototypes */
static double compute_sig(double avg1, double var1, double avg2, double var2);
static void compute_stats(const struct symbol_count *count, unsigned n,
double *avg, double *var);
static void load_file(const char *path, int count_index);
static void *malloc_checked(size_t size);
static void print_report(void);
static void print_report_line(const struct symbol_info *symbol);
static int read_line(FILE *file, char *binary, char *name,
unsigned long *samples);
static enum symbol_class symbol_classify(const char *binary, const char *name);
static unsigned string_hash(const char *s, size_t size);
static struct symbol_info *symbol_find_or_add(const char *binary,
const char *name);
static unsigned symbol_hash(const char *binary, const char *name);
static int symbol_qsort_compare(const void *p1, const void *p2);
static void symbol_tally(const char *binary, const char *name,
unsigned long samples, int count_index);
static unsigned symbols_count(void);
static void usage(const char *argv0);
#define MALLOC_CHECKED(type, count) \
((type *) malloc_checked(sizeof(type) * (count)))
#if DEBUG
#define dprintf(...) do { \
fprintf(stderr, "debug(%s:%d): ", __FUNCTION__, __LINE__); \
fprintf(stderr, __VA_ARGS__); \
} while(0)
#else
#define dprintf(...)
#endif
int main(int argc, char **argv) {
int i;
#ifdef DEBUG
/* disable buffering so the output mixes correctly */
setvbuf(stdout, NULL, _IONBF, 0);
setvbuf(stderr, NULL, _IONBF, 0);
#endif
if (argc < 3) usage(argv[0]);
/* load left-hand files */
for (i = 1; i < argc; i++) {
if (strcmp(argv[i], "-r") == 0) {
i++;
break;
}
if (argc == 3 && i == 2) break;
load_file(argv[i], 0);
n1++;
}
/* load right-hand files */
for (; i < argc; i++) {
load_file(argv[i], 1);
n2++;
}
if (n1 < 1 || n2 < 1) usage(argv[0]);
/* report analysis results */
print_report();
return 0;
}
static double compute_sig(double avg1, double var1, double avg2, double var2) {
double df, t, var;
/* prevent division by zero with lack of variance */
var = var1 / n1 + var2 / n2;
if (var <= 0 || n1 <= 1 || n2 <= 1) return -1;
/* do we have enough degrees of freedom? */
df = var * var / (
var1 * var1 / (n1 * n1 * (n1 - 1)) +
var2 * var2 / (n2 * n2 * (n2 - 1)));
if (df < 1) return -1;
/* perform t-test */
t = (avg1 - avg2) / sqrt(var);
return student_t_p_2tail(t, df);
}
static void compute_stats(const struct symbol_count *count, unsigned n,
double *avg, double *var) {
double sum;
assert(count);
assert(avg);
assert(var);
sum = count->sum;
if (n < 1) {
*avg = 0;
} else {
*avg = sum / n;
}
if (n < 2) {
*var = 0;
} else {
*var = (count->sum2 - sum * sum / n) / (n - 1);
}
}
static void load_file(const char *path, int count_index) {
char binary[PROC_NAME_LEN];
FILE *file;
char name[SYMBOL_NAME_SIZE];
unsigned long samples;
assert(path);
assert(count_index == 0 || count_index == 1);
file = fopen(path, "r");
if (!file) {
fprintf(stderr, "error: cannot open \"%s\": %s\n",
path, strerror(errno));
exit(1);
}
while (read_line(file, binary, name, &samples)) {
symbol_tally(binary, name, samples, count_index);
}
fclose(file);
}
static void *malloc_checked(size_t size) {
void *p;
if (!size) return NULL;
p = malloc(size);
if (!p) {
fprintf(stderr, "error: malloc cannot allocate %lu bytes: %s\n",
(unsigned long) size, strerror(errno));
exit(-1);
}
return p;
}
static void print_report(void) {
unsigned i, index, symbol_count;
struct symbol_info *symbol, **symbol_list;
/* list the symbols in an array for sorting */
symbol_count = symbols_count();
symbol_list = MALLOC_CHECKED(struct symbol_info *, symbol_count);
index = 0;
for (symbol = symbols; symbol; symbol = symbol->next) {
symbol_list[index++] = symbol;
/* sort by difference in average, multiply both sides by
* n1 * n2 to avoid division
*/
symbol->diff = (long) (symbol->count[1].sum * n1) -
(long) (symbol->count[0].sum * n2);
}
assert(index == symbol_count);
/* sort symbols */
qsort(symbol_list, symbol_count, sizeof(struct symbol_info *),
symbol_qsort_compare);
printf("%-*s %-*s ------avg------ ----stdev---- diff sig\n",
PROC_NAME_WIDTH, "binary", SYMBOL_NAME_WIDTH, "symbol");
printf("%-*s left right left right\n",
PROC_NAME_WIDTH + SYMBOL_NAME_WIDTH + 1, "");
printf("\n");
for (i = 0; i < symbol_count; i++) {
if (i > 0 && symbol_list[i]->class >= sc_process &&
symbol_list[i]->class != symbol_list[i - 1]->class) {
printf("\n");
}
print_report_line(symbol_list[i]);
}
printf("\n");
printf("significance levels (two-tailed):\n");
printf(" * p < 0.05\n");
printf(" ** p < 0.01\n");
printf(" *** p < 0.001\n");
}
static void print_report_line(const struct symbol_info *symbol) {
double avg1, avg2, p, var1, var2;
/* compute statistics; t is Welch's t, which is a t-test that allows
* for unpaired samples with unequal variance; df is the degrees of
* freedom as given by the Welch-Satterthwaite equation
*/
compute_stats(&symbol->count[0], n1, &avg1, &var1);
compute_stats(&symbol->count[1], n2, &avg2, &var2);
p = compute_sig(avg1, var1, avg2, var2);
/* list applicable values */
assert(PROC_NAME_WIDTH <= PROC_NAME_LEN);
assert(SYMBOL_NAME_WIDTH <= SYMBOL_NAME_SIZE);
printf("%-*.*s %-*.*s",
PROC_NAME_WIDTH, PROC_NAME_WIDTH, symbol->binary,
SYMBOL_NAME_WIDTH, SYMBOL_NAME_WIDTH, symbol->name);
if (symbol->count[0].sum > 0) {
printf("%8.0f", avg1);
} else {
printf(" ");
}
if (symbol->count[1].sum > 0) {
printf("%8.0f", avg2);
} else {
printf(" ");
}
if (symbol->count[0].sum > 0 && n1 >= 2) {
printf("%7.0f", sqrt(var1));
} else {
printf(" ");
}
if (symbol->count[1].sum > 0 && n2 >= 2) {
printf("%7.0f", sqrt(var2));
} else {
printf(" ");
}
printf("%8.0f ", avg2 - avg1);
if (p >= 0) {
if (p <= 0.05) printf("*");
if (p <= 0.01) printf("*");
if (p <= 0.001) printf("*");
}
printf("\n");
}
static int read_line(FILE *file, char *binary, char *name,
unsigned long *samples) {
int c, index;
assert(file);
assert(binary);
assert(name);
assert(samples);
c = fgetc(file);
if (c == EOF) return 0;
/* read binary name, truncating if necessary */
index = 0;
while (c != '\t' && c != '\n') {
if (index < PROC_NAME_LEN) binary[index++] = c;
c = fgetc(file);
}
if (index < PROC_NAME_LEN) binary[index] = 0;
/* read tab */
if (c != '\t') {
fprintf(stderr, "error: garbage %d after binary name\n", c);
exit(1);
}
c = fgetc(file);
/* read symbol name, truncating if necessary */
index = 0;
while (c != '\t' && c != '\n') {
if (index < SYMBOL_NAME_SIZE) name[index++] = c;
c = fgetc(file);
}
if (index < SYMBOL_NAME_SIZE) name[index] = 0;
/* read tab */
if (c != '\t') {
fprintf(stderr, "error: garbage %d after symbol name\n", c);
exit(1);
}
c = fgetc(file);
/* read number of samples */
*samples = 0;
while (c >= '0' && c <= '9') {
*samples = *samples * 10 + (c - '0');
c = fgetc(file);
}
/* read newline */
if (c != '\n') {
fprintf(stderr, "error: garbage %d after sample count\n", c);
exit(1);
}
return 1;
}
static unsigned string_hash(const char *s, size_t size) {
unsigned result = 0;
assert(s);
while (*s && size-- > 0) {
result = result * 31 + *(s++);
}
return result;
}
static enum symbol_class symbol_classify(const char *binary, const char *name) {
if (strncmp(binary, "(total)", PROC_NAME_LEN) == 0) return sc_total;
if (strncmp(binary, "(idle)", PROC_NAME_LEN) == 0) return sc_idle;
if (strncmp(binary, "(system)", PROC_NAME_LEN) == 0) return sc_system;
if (strncmp(binary, "(user)", PROC_NAME_LEN) == 0) return sc_user;
if (strncmp(name, "(total)", SYMBOL_NAME_SIZE) == 0) return sc_process;
return sc_symbol;
}
static struct symbol_info *symbol_find_or_add(const char *binary,
const char *name) {
struct symbol_info **ptr, *symbol;
assert(binary);
assert(name);
/* look up symbol in hash table */
ptr = &symbol_hashtab[symbol_hash(binary, name) % SYMBOL_HASHTAB_SIZE];
while ((symbol = *ptr)) {
if (strncmp(symbol->binary, binary, PROC_NAME_LEN) == 0 &&
strncmp(symbol->name, name, SYMBOL_NAME_SIZE) == 0) {
return symbol;
}
ptr = &symbol->hashtab_next;
}
/* unknown symbol, add it */
*ptr = symbol = MALLOC_CHECKED(struct symbol_info, 1);
memset(symbol, 0, sizeof(struct symbol_info));
strncpy(symbol->binary, binary, PROC_NAME_LEN);
strncpy(symbol->name, name, SYMBOL_NAME_SIZE);
symbol->count[0].min = ~0UL;
symbol->count[1].min = ~0UL;
symbol->class = symbol_classify(binary, name);
/* also add to linked list */
symbol->next = symbols;
symbols = symbol;
return symbol;
}
static unsigned symbol_hash(const char *binary, const char *name) {
return string_hash(binary, PROC_NAME_LEN) +
string_hash(name, SYMBOL_NAME_SIZE);
}
static int symbol_qsort_compare(const void *p1, const void *p2) {
int r;
const struct symbol_info *s1, *s2;
assert(p1);
assert(p2);
s1 = *(const struct symbol_info **) p1;
s2 = *(const struct symbol_info **) p2;
assert(s1);
assert(s2);
/* totals come first */
if (s1->class < s2->class) return -1;
if (s1->class > s2->class) return 1;
/* sort by difference in average */
if (s1->diff < s2->diff) return -1;
if (s1->diff > s2->diff) return 1;
/* otherwise, by name */
r = strncmp(s1->binary, s2->binary, PROC_NAME_LEN);
if (r) return r;
return strncmp(s1->name, s2->name, SYMBOL_NAME_SIZE);
}
static void symbol_tally(const char *binary, const char *name,
unsigned long samples, int count_index) {
struct symbol_count *count;
struct symbol_info *symbol;
/* look up or add symbol */
symbol = symbol_find_or_add(binary, name);
/* update count */
count = &symbol->count[count_index];
count->sum += samples;
count->sum2 += (unsigned long long) samples * samples;
if (count->min > samples) count->min = samples;
if (count->max < samples) count->max = samples;
}
static unsigned symbols_count(void) {
int count = 0;
const struct symbol_info *symbol;
for (symbol = symbols; symbol; symbol = symbol->next) {
count++;
}
return count;
}
static void usage(const char *argv0) {
printf("usage:\n");
printf(" %s leftfile rightfile\n", argv0);
printf(" %s leftfile... -r rightfile...\n", argv0);
printf("\n");
printf("sprofdiff compares the sprofile information from multiple\n");
printf("output files of sprofalyze -d.\n");
exit(1);
}