Commit c2488d70 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
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selftests/bpf: make veristat's verifier log parsing faster and more robust 



Make sure veristat doesn't spend ridiculous amount of time parsing
verifier stats from verifier log, especially for very large logs or
truncated logs (e.g., when verifier returns -ENOSPC due to too small
buffer). For this, parse lines from the end of the log and make sure we
parse only up to 100 last lines, where stats should be, if at all.

Suggested-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220923175913.3272430-3-andrii@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 067f4f29

tools/testing/selftests/bpf/veristat.c

+20 −9
Original line number Diff line number Diff line
@@ -419,19 +419,30 @@ static void free_verif_stats(struct verif_stats *stats, size_t stat_cnt) 


static char verif_log_buf[64 * 1024];



static int parse_verif_log(const char *buf, size_t buf_sz, struct verif_stats *s)

#define MAX_PARSED_LOG_LINES 100



static int parse_verif_log(char * const buf, size_t buf_sz, struct verif_stats *s)

{

	const char *next;

	int pos;

	const char *cur;

	int pos, lines;



	buf[buf_sz - 1] = '\0';



	for (pos = 0; buf[0]; buf = next) {

		if (buf[0] == '\n')

			buf++;

		next = strchrnul(&buf[pos], '\n');

	for (pos = strlen(buf) - 1, lines = 0; pos >= 0 && lines < MAX_PARSED_LOG_LINES; lines++) {

		/* find previous endline or otherwise take the start of log buf */

		for (cur = &buf[pos]; cur > buf && cur[0] != '\n'; cur--, pos--) {

		}

		/* next time start from end of previous line (or pos goes to <0) */

		pos--;

		/* if we found endline, point right after endline symbol;

		 * otherwise, stay at the beginning of log buf

		 */

		if (cur[0] == '\n')

			cur++;



		if (1 == sscanf(buf, "verification time %ld usec\n", &s->stats[DURATION]))

		if (1 == sscanf(cur, "verification time %ld usec\n", &s->stats[DURATION]))

			continue;

		if (6 == sscanf(buf, "processed %ld insns (limit %*d) max_states_per_insn %ld total_states %ld peak_states %ld mark_read %ld",

		if (6 == sscanf(cur, "processed %ld insns (limit %*d) max_states_per_insn %ld total_states %ld peak_states %ld mark_read %ld",

				&s->stats[TOTAL_INSNS],

				&s->stats[MAX_STATES_PER_INSN],

				&s->stats[TOTAL_STATES],