Add ability to sort results by absolute values of specified stats. This
is especially useful to find biggest deviations in comparison mode. When
comparing verifier change effect against a large base of BPF object
files, it's necessary to see big changes both in positive and negative
directions, as both might be a signal for regressions or bugs.
The syntax is natural, e.g., adding `-s '|insns_diff|'^` will instruct
veristat to sort by absolute value of instructions difference in
ascending order.
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
---
tools/testing/selftests/bpf/veristat.c | 68 +++++++++++++++++++++-----
1 file changed, 56 insertions(+), 12 deletions(-)
diff --git a/tools/testing/selftests/bpf/veristat.c b/tools/testing/selftests/bpf/veristat.c
index 655095810d4a..102914f70573 100644
--- a/tools/testing/selftests/bpf/veristat.c
+++ b/tools/testing/selftests/bpf/veristat.c
@@ -18,6 +18,7 @@
#include <libelf.h>
#include <gelf.h>
#include <float.h>
+#include <math.h>
#ifndef ARRAY_SIZE
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
@@ -99,6 +100,7 @@ struct stat_specs {
enum stat_id ids[ALL_STATS_CNT];
enum stat_variant variants[ALL_STATS_CNT];
bool asc[ALL_STATS_CNT];
+ bool abs[ALL_STATS_CNT];
int lens[ALL_STATS_CNT * 3]; /* 3x for comparison mode */
};
@@ -133,6 +135,7 @@ struct filter {
int stat_id;
enum stat_variant stat_var;
long value;
+ bool abs;
};
static struct env {
@@ -455,7 +458,8 @@ static struct {
{ OP_EQ, "=" },
};
-static bool parse_stat_id_var(const char *name, size_t len, int *id, enum stat_variant *var);
+static bool parse_stat_id_var(const char *name, size_t len, int *id,
+ enum stat_variant *var, bool *is_abs);
static int append_filter(struct filter **filters, int *cnt, const char *str)
{
@@ -488,13 +492,14 @@ static int append_filter(struct filter **filters, int *cnt, const char *str)
long val;
const char *end = str;
const char *op_str;
+ bool is_abs;
op_str = operators[i].op_str;
p = strstr(str, op_str);
if (!p)
continue;
- if (!parse_stat_id_var(str, p - str, &id, &var)) {
+ if (!parse_stat_id_var(str, p - str, &id, &var, &is_abs)) {
fprintf(stderr, "Unrecognized stat name in '%s'!\n", str);
return -EINVAL;
}
@@ -533,6 +538,7 @@ static int append_filter(struct filter **filters, int *cnt, const char *str)
f->stat_id = id;
f->stat_var = var;
f->op = operators[i].op_kind;
+ f->abs = true;
f->value = val;
*cnt += 1;
@@ -657,7 +663,8 @@ static struct stat_def {
[MARK_READ_MAX_LEN] = { "Max mark read length", {"max_mark_read_len", "mark_read"}, },
};
-static bool parse_stat_id_var(const char *name, size_t len, int *id, enum stat_variant *var)
+static bool parse_stat_id_var(const char *name, size_t len, int *id,
+ enum stat_variant *var, bool *is_abs)
{
static const char *var_sfxs[] = {
[VARIANT_A] = "_a",
@@ -667,6 +674,14 @@ static bool parse_stat_id_var(const char *name, size_t len, int *id, enum stat_v
};
int i, j, k;
+ /* |<stat>| means we take absolute value of given stat */
+ *is_abs = false;
+ if (len > 2 && name[0] == '|' && name[len - 1] == '|') {
+ *is_abs = true;
+ name += 1;
+ len -= 2;
+ }
+
for (i = 0; i < ARRAY_SIZE(stat_defs); i++) {
struct stat_def *def = &stat_defs[i];
size_t alias_len, sfx_len;
@@ -722,7 +737,7 @@ static bool is_desc_sym(char c)
static int parse_stat(const char *stat_name, struct stat_specs *specs)
{
int id;
- bool has_order = false, is_asc = false;
+ bool has_order = false, is_asc = false, is_abs = false;
size_t len = strlen(stat_name);
enum stat_variant var;
@@ -737,7 +752,7 @@ static int parse_stat(const char *stat_name, struct stat_specs *specs)
len -= 1;
}
- if (!parse_stat_id_var(stat_name, len, &id, &var)) {
+ if (!parse_stat_id_var(stat_name, len, &id, &var, &is_abs)) {
fprintf(stderr, "Unrecognized stat name '%s'\n", stat_name);
return -ESRCH;
}
@@ -745,6 +760,7 @@ static int parse_stat(const char *stat_name, struct stat_specs *specs)
specs->ids[specs->spec_cnt] = id;
specs->variants[specs->spec_cnt] = var;
specs->asc[specs->spec_cnt] = has_order ? is_asc : stat_defs[id].asc_by_default;
+ specs->abs[specs->spec_cnt] = is_abs;
specs->spec_cnt++;
return 0;
@@ -1103,7 +1119,7 @@ static int process_obj(const char *filename)
}
static int cmp_stat(const struct verif_stats *s1, const struct verif_stats *s2,
- enum stat_id id, bool asc)
+ enum stat_id id, bool asc, bool abs)
{
int cmp = 0;
@@ -1124,6 +1140,11 @@ static int cmp_stat(const struct verif_stats *s1, const struct verif_stats *s2,
long v1 = s1->stats[id];
long v2 = s2->stats[id];
+ if (abs) {
+ v1 = v1 < 0 ? -v1 : v1;
+ v2 = v2 < 0 ? -v2 : v2;
+ }
+
if (v1 != v2)
cmp = v1 < v2 ? -1 : 1;
break;
@@ -1142,7 +1163,8 @@ static int cmp_prog_stats(const void *v1, const void *v2)
int i, cmp;
for (i = 0; i < env.sort_spec.spec_cnt; i++) {
- cmp = cmp_stat(s1, s2, env.sort_spec.ids[i], env.sort_spec.asc[i]);
+ cmp = cmp_stat(s1, s2, env.sort_spec.ids[i],
+ env.sort_spec.asc[i], env.sort_spec.abs[i]);
if (cmp != 0)
return cmp;
}
@@ -1211,7 +1233,8 @@ static void fetch_join_stat_value(const struct verif_stats_join *s,
static int cmp_join_stat(const struct verif_stats_join *s1,
const struct verif_stats_join *s2,
- enum stat_id id, enum stat_variant var, bool asc)
+ enum stat_id id, enum stat_variant var,
+ bool asc, bool abs)
{
const char *str1 = NULL, *str2 = NULL;
double v1, v2;
@@ -1220,6 +1243,11 @@ static int cmp_join_stat(const struct verif_stats_join *s1,
fetch_join_stat_value(s1, id, var, &str1, &v1);
fetch_join_stat_value(s2, id, var, &str2, &v2);
+ if (abs) {
+ v1 = fabs(v1);
+ v2 = fabs(v2);
+ }
+
if (str1)
cmp = strcmp(str1, str2);
else if (v1 != v2)
@@ -1237,7 +1265,8 @@ static int cmp_join_stats(const void *v1, const void *v2)
cmp = cmp_join_stat(s1, s2,
env.sort_spec.ids[i],
env.sort_spec.variants[i],
- env.sort_spec.asc[i]);
+ env.sort_spec.asc[i],
+ env.sort_spec.abs[i]);
if (cmp != 0)
return cmp;
}
@@ -1720,6 +1749,9 @@ static bool is_join_stat_filter_matched(struct filter *f, const struct verif_sta
fetch_join_stat_value(stats, f->stat_id, f->stat_var, &str, &value);
+ if (f->abs)
+ value = fabs(value);
+
switch (f->op) {
case OP_EQ: return value > f->value - eps && value < f->value + eps;
case OP_NEQ: return value < f->value - eps || value > f->value + eps;
@@ -1766,7 +1798,7 @@ static int handle_comparison_mode(void)
struct stat_specs base_specs = {}, comp_specs = {};
struct stat_specs tmp_sort_spec;
enum resfmt cur_fmt;
- int err, i, j, last_idx;
+ int err, i, j, last_idx, cnt;
if (env.filename_cnt != 2) {
fprintf(stderr, "Comparison mode expects exactly two input CSV files!\n\n");
@@ -1879,7 +1911,7 @@ static int handle_comparison_mode(void)
env.join_stat_cnt += 1;
}
- /* now sort joined results accorsing to sort spec */
+ /* now sort joined results according to sort spec */
qsort(env.join_stats, env.join_stat_cnt, sizeof(*env.join_stats), cmp_join_stats);
/* for human-readable table output we need to do extra pass to
@@ -1896,16 +1928,22 @@ static int handle_comparison_mode(void)
output_comp_headers(cur_fmt);
last_idx = -1;
+ cnt = 0;
for (i = 0; i < env.join_stat_cnt; i++) {
const struct verif_stats_join *join = &env.join_stats[i];
if (!should_output_join_stats(join))
continue;
+ if (env.top_n && cnt >= env.top_n)
+ break;
+
if (cur_fmt == RESFMT_TABLE_CALCLEN)
last_idx = i;
output_comp_stats(join, cur_fmt, i == last_idx);
+
+ cnt++;
}
if (cur_fmt == RESFMT_TABLE_CALCLEN) {
@@ -1920,6 +1958,9 @@ static bool is_stat_filter_matched(struct filter *f, const struct verif_stats *s
{
long value = stats->stats[f->stat_id];
+ if (f->abs)
+ value = value < 0 ? -value : value;
+
switch (f->op) {
case OP_EQ: return value == f->value;
case OP_NEQ: return value != f->value;
@@ -1964,7 +2005,7 @@ static bool should_output_stats(const struct verif_stats *stats)
static void output_prog_stats(void)
{
const struct verif_stats *stats;
- int i, last_stat_idx = 0;
+ int i, last_stat_idx = 0, cnt = 0;
if (env.out_fmt == RESFMT_TABLE) {
/* calculate column widths */
@@ -1984,7 +2025,10 @@ static void output_prog_stats(void)
stats = &env.prog_stats[i];
if (!should_output_stats(stats))
continue;
+ if (env.top_n && cnt >= env.top_n)
+ break;
output_stats(stats, env.out_fmt, i == last_stat_idx);
+ cnt++;
}
}
--
2.34.1
