forked from mirrors/linux
		
	perf srcline: Use long-running addr2line per DSO
Invoking addr2line in a separate subprocess, one for each required lookup, takes a terribly long time. This patch introduces a long-running addr2line process for each DSO, *DRAMATICALLY* speeding up runs of perf. What used to take tens of minutes now takes tens of seconds. Debian bug report about this issue: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=911815 Signed-off-by: Tony Garnock-Jones <tonyg@leastfixedpoint.com> Tested-by: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210916120939.453536-1-tonyg@leastfixedpoint.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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					 1 changed files with 258 additions and 96 deletions
				
			
		|  | @ -1,8 +1,10 @@ | |||
| // SPDX-License-Identifier: GPL-2.0
 | ||||
| #include <inttypes.h> | ||||
| #include <signal.h> | ||||
| #include <stdio.h> | ||||
| #include <stdlib.h> | ||||
| #include <string.h> | ||||
| #include <sys/types.h> | ||||
| 
 | ||||
| #include <linux/kernel.h> | ||||
| #include <linux/string.h> | ||||
|  | @ -15,6 +17,7 @@ | |||
| #include "srcline.h" | ||||
| #include "string2.h" | ||||
| #include "symbol.h" | ||||
| #include "subcmd/run-command.h" | ||||
| 
 | ||||
| bool srcline_full_filename; | ||||
| 
 | ||||
|  | @ -119,6 +122,8 @@ static struct symbol *new_inline_sym(struct dso *dso, | |||
| 	return inline_sym; | ||||
| } | ||||
| 
 | ||||
| #define MAX_INLINE_NEST 1024 | ||||
| 
 | ||||
| #ifdef HAVE_LIBBFD_SUPPORT | ||||
| 
 | ||||
| /*
 | ||||
|  | @ -273,8 +278,6 @@ static void addr2line_cleanup(struct a2l_data *a2l) | |||
| 	free(a2l); | ||||
| } | ||||
| 
 | ||||
| #define MAX_INLINE_NEST 1024 | ||||
| 
 | ||||
| static int inline_list__append_dso_a2l(struct dso *dso, | ||||
| 				       struct inline_node *node, | ||||
| 				       struct symbol *sym) | ||||
|  | @ -361,26 +364,14 @@ void dso__free_a2l(struct dso *dso) | |||
| 	dso->a2l = NULL; | ||||
| } | ||||
| 
 | ||||
| static struct inline_node *addr2inlines(const char *dso_name, u64 addr, | ||||
| 					struct dso *dso, struct symbol *sym) | ||||
| { | ||||
| 	struct inline_node *node; | ||||
| 
 | ||||
| 	node = zalloc(sizeof(*node)); | ||||
| 	if (node == NULL) { | ||||
| 		perror("not enough memory for the inline node"); | ||||
| 		return NULL; | ||||
| 	} | ||||
| 
 | ||||
| 	INIT_LIST_HEAD(&node->val); | ||||
| 	node->addr = addr; | ||||
| 
 | ||||
| 	addr2line(dso_name, addr, NULL, NULL, dso, true, node, sym); | ||||
| 	return node; | ||||
| } | ||||
| 
 | ||||
| #else /* HAVE_LIBBFD_SUPPORT */ | ||||
| 
 | ||||
| struct a2l_subprocess { | ||||
| 	struct child_process addr2line; | ||||
| 	FILE *to_child; | ||||
| 	FILE *from_child; | ||||
| }; | ||||
| 
 | ||||
| static int filename_split(char *filename, unsigned int *line_nr) | ||||
| { | ||||
| 	char *sep; | ||||
|  | @ -402,114 +393,285 @@ static int filename_split(char *filename, unsigned int *line_nr) | |||
| 	return 0; | ||||
| } | ||||
| 
 | ||||
| static int addr2line(const char *dso_name, u64 addr, | ||||
| 		     char **file, unsigned int *line_nr, | ||||
| 		     struct dso *dso __maybe_unused, | ||||
| 		     bool unwind_inlines __maybe_unused, | ||||
| 		     struct inline_node *node __maybe_unused, | ||||
| 		     struct symbol *sym __maybe_unused) | ||||
| static void addr2line_subprocess_cleanup(struct a2l_subprocess *a2l) | ||||
| { | ||||
| 	FILE *fp; | ||||
| 	char cmd[PATH_MAX]; | ||||
| 	char *filename = NULL; | ||||
| 	size_t len; | ||||
| 	int ret = 0; | ||||
| 
 | ||||
| 	scnprintf(cmd, sizeof(cmd), "addr2line -e %s %016"PRIx64, | ||||
| 		  dso_name, addr); | ||||
| 
 | ||||
| 	fp = popen(cmd, "r"); | ||||
| 	if (fp == NULL) { | ||||
| 		pr_warning("popen failed for %s\n", dso_name); | ||||
| 		return 0; | ||||
| 	if (a2l->addr2line.pid != -1) { | ||||
| 		kill(a2l->addr2line.pid, SIGKILL); | ||||
| 		finish_command(&a2l->addr2line); /* ignore result, we don't care */ | ||||
| 		a2l->addr2line.pid = -1; | ||||
| 	} | ||||
| 
 | ||||
| 	if (getline(&filename, &len, fp) < 0 || !len) { | ||||
| 		pr_warning("addr2line has no output for %s\n", dso_name); | ||||
| 	if (a2l->to_child != NULL) { | ||||
| 		fclose(a2l->to_child); | ||||
| 		a2l->to_child = NULL; | ||||
| 	} | ||||
| 
 | ||||
| 	if (a2l->from_child != NULL) { | ||||
| 		fclose(a2l->from_child); | ||||
| 		a2l->from_child = NULL; | ||||
| 	} | ||||
| 
 | ||||
| 	free(a2l); | ||||
| } | ||||
| 
 | ||||
| static struct a2l_subprocess *addr2line_subprocess_init(const char *path) | ||||
| { | ||||
| 	const char *argv[] = { "addr2line", "-e", path, "-i", "-f", NULL }; | ||||
| 	struct a2l_subprocess *a2l = zalloc(sizeof(*a2l)); | ||||
| 	int start_command_status = 0; | ||||
| 
 | ||||
| 	if (a2l == NULL) | ||||
| 		goto out; | ||||
| 
 | ||||
| 	a2l->to_child = NULL; | ||||
| 	a2l->from_child = NULL; | ||||
| 
 | ||||
| 	a2l->addr2line.pid = -1; | ||||
| 	a2l->addr2line.in = -1; | ||||
| 	a2l->addr2line.out = -1; | ||||
| 	a2l->addr2line.no_stderr = 1; | ||||
| 
 | ||||
| 	a2l->addr2line.argv = argv; | ||||
| 	start_command_status = start_command(&a2l->addr2line); | ||||
| 	a2l->addr2line.argv = NULL; /* it's not used after start_command; avoid dangling pointers */ | ||||
| 
 | ||||
| 	if (start_command_status != 0) { | ||||
| 		pr_warning("could not start addr2line for %s: start_command return code %d\n", | ||||
| 			   path, | ||||
| 			   start_command_status); | ||||
| 		goto out; | ||||
| 	} | ||||
| 
 | ||||
| 	ret = filename_split(filename, line_nr); | ||||
| 	if (ret != 1) { | ||||
| 		free(filename); | ||||
| 	a2l->to_child = fdopen(a2l->addr2line.in, "w"); | ||||
| 	if (a2l->to_child == NULL) { | ||||
| 		pr_warning("could not open write-stream to addr2line of %s\n", path); | ||||
| 		goto out; | ||||
| 	} | ||||
| 
 | ||||
| 	*file = filename; | ||||
| 	a2l->from_child = fdopen(a2l->addr2line.out, "r"); | ||||
| 	if (a2l->from_child == NULL) { | ||||
| 		pr_warning("could not open read-stream from addr2line of %s\n", path); | ||||
| 		goto out; | ||||
| 	} | ||||
| 
 | ||||
| 	return a2l; | ||||
| 
 | ||||
| out: | ||||
| 	pclose(fp); | ||||
| 	if (a2l) | ||||
| 		addr2line_subprocess_cleanup(a2l); | ||||
| 
 | ||||
| 	return NULL; | ||||
| } | ||||
| 
 | ||||
| static int read_addr2line_record(struct a2l_subprocess *a2l, | ||||
| 				 char **function, | ||||
| 				 char **filename, | ||||
| 				 unsigned int *line_nr) | ||||
| { | ||||
| 	/*
 | ||||
| 	 * Returns: | ||||
| 	 * -1 ==> error | ||||
| 	 * 0 ==> sentinel (or other ill-formed) record read | ||||
| 	 * 1 ==> a genuine record read | ||||
| 	 */ | ||||
| 	char *line = NULL; | ||||
| 	size_t line_len = 0; | ||||
| 	unsigned int dummy_line_nr = 0; | ||||
| 	int ret = -1; | ||||
| 
 | ||||
| 	if (function != NULL) | ||||
| 		zfree(function); | ||||
| 
 | ||||
| 	if (filename != NULL) | ||||
| 		zfree(filename); | ||||
| 
 | ||||
| 	if (line_nr != NULL) | ||||
| 		*line_nr = 0; | ||||
| 
 | ||||
| 	if (getline(&line, &line_len, a2l->from_child) < 0 || !line_len) | ||||
| 		goto error; | ||||
| 
 | ||||
| 	if (function != NULL) | ||||
| 		*function = strdup(strim(line)); | ||||
| 
 | ||||
| 	zfree(&line); | ||||
| 	line_len = 0; | ||||
| 
 | ||||
| 	if (getline(&line, &line_len, a2l->from_child) < 0 || !line_len) | ||||
| 		goto error; | ||||
| 
 | ||||
| 	if (filename_split(line, line_nr == NULL ? &dummy_line_nr : line_nr) == 0) { | ||||
| 		ret = 0; | ||||
| 		goto error; | ||||
| 	} | ||||
| 
 | ||||
| 	if (filename != NULL) | ||||
| 		*filename = strdup(line); | ||||
| 
 | ||||
| 	zfree(&line); | ||||
| 	line_len = 0; | ||||
| 
 | ||||
| 	return 1; | ||||
| 
 | ||||
| error: | ||||
| 	free(line); | ||||
| 	if (function != NULL) | ||||
| 		zfree(function); | ||||
| 	if (filename != NULL) | ||||
| 		zfree(filename); | ||||
| 	return ret; | ||||
| } | ||||
| 
 | ||||
| void dso__free_a2l(struct dso *dso __maybe_unused) | ||||
| static int inline_list__append_record(struct dso *dso, | ||||
| 				      struct inline_node *node, | ||||
| 				      struct symbol *sym, | ||||
| 				      const char *function, | ||||
| 				      const char *filename, | ||||
| 				      unsigned int line_nr) | ||||
| { | ||||
| 	struct symbol *inline_sym = new_inline_sym(dso, sym, function); | ||||
| 
 | ||||
| 	return inline_list__append(inline_sym, srcline_from_fileline(filename, line_nr), node); | ||||
| } | ||||
| 
 | ||||
| static struct inline_node *addr2inlines(const char *dso_name, u64 addr, | ||||
| 					struct dso *dso __maybe_unused, | ||||
| 					struct symbol *sym) | ||||
| static int addr2line(const char *dso_name, u64 addr, | ||||
| 		     char **file, unsigned int *line_nr, | ||||
| 		     struct dso *dso, | ||||
| 		     bool unwind_inlines, | ||||
| 		     struct inline_node *node, | ||||
| 		     struct symbol *sym __maybe_unused) | ||||
| { | ||||
| 	FILE *fp; | ||||
| 	char cmd[PATH_MAX]; | ||||
| 	struct inline_node *node; | ||||
| 	char *filename = NULL; | ||||
| 	char *funcname = NULL; | ||||
| 	size_t filelen, funclen; | ||||
| 	unsigned int line_nr = 0; | ||||
| 	struct a2l_subprocess *a2l = dso->a2l; | ||||
| 	char *record_function = NULL; | ||||
| 	char *record_filename = NULL; | ||||
| 	unsigned int record_line_nr = 0; | ||||
| 	int record_status = -1; | ||||
| 	int ret = 0; | ||||
| 	size_t inline_count = 0; | ||||
| 
 | ||||
| 	scnprintf(cmd, sizeof(cmd), "addr2line -e %s -i -f %016"PRIx64, | ||||
| 		  dso_name, addr); | ||||
| 
 | ||||
| 	fp = popen(cmd, "r"); | ||||
| 	if (fp == NULL) { | ||||
| 		pr_err("popen failed for %s\n", dso_name); | ||||
| 		return NULL; | ||||
| 	if (!a2l) { | ||||
| 		dso->a2l = addr2line_subprocess_init(dso_name); | ||||
| 		a2l = dso->a2l; | ||||
| 	} | ||||
| 
 | ||||
| 	if (a2l == NULL) { | ||||
| 		if (!symbol_conf.disable_add2line_warn) | ||||
| 			pr_warning("%s %s: addr2line_subprocess_init failed\n", __func__, dso_name); | ||||
| 		goto out; | ||||
| 	} | ||||
| 
 | ||||
| 	/*
 | ||||
| 	 * Send our request and then *deliberately* send something that can't be interpreted as | ||||
| 	 * a valid address to ask addr2line about (namely, ","). This causes addr2line to first | ||||
| 	 * write out the answer to our request, in an unbounded/unknown number of records, and | ||||
| 	 * then to write out the lines "??" and "??:0", so that we can detect when it has | ||||
| 	 * finished giving us anything useful. We have to be careful about the first record, | ||||
| 	 * though, because it may be genuinely unknown, in which case we'll get two sets of | ||||
| 	 * "??"/"??:0" lines. | ||||
| 	 */ | ||||
| 	if (fprintf(a2l->to_child, "%016"PRIx64"\n,\n", addr) < 0 || fflush(a2l->to_child) != 0) { | ||||
| 		pr_warning("%s %s: could not send request\n", __func__, dso_name); | ||||
| 		goto out; | ||||
| 	} | ||||
| 
 | ||||
| 	switch (read_addr2line_record(a2l, &record_function, &record_filename, &record_line_nr)) { | ||||
| 	case -1: | ||||
| 		pr_warning("%s %s: could not read first record\n", __func__, dso_name); | ||||
| 		goto out; | ||||
| 	case 0: | ||||
| 		/*
 | ||||
| 		 * The first record was invalid, so return failure, but first read another | ||||
| 		 * record, since we asked a junk question and have to clear the answer out. | ||||
| 		 */ | ||||
| 		switch (read_addr2line_record(a2l, NULL, NULL, NULL)) { | ||||
| 		case -1: | ||||
| 			pr_warning("%s %s: could not read delimiter record\n", __func__, dso_name); | ||||
| 			break; | ||||
| 		case 0: | ||||
| 			/* As expected. */ | ||||
| 			break; | ||||
| 		default: | ||||
| 			pr_warning("%s %s: unexpected record instead of sentinel", | ||||
| 				   __func__, dso_name); | ||||
| 			break; | ||||
| 		} | ||||
| 		goto out; | ||||
| 	default: | ||||
| 		break; | ||||
| 	} | ||||
| 
 | ||||
| 	if (file) { | ||||
| 		*file = strdup(record_filename); | ||||
| 		ret = 1; | ||||
| 	} | ||||
| 	if (line_nr) | ||||
| 		*line_nr = record_line_nr; | ||||
| 
 | ||||
| 	if (unwind_inlines) { | ||||
| 		if (node && inline_list__append_record(dso, node, sym, | ||||
| 						       record_function, | ||||
| 						       record_filename, | ||||
| 						       record_line_nr)) { | ||||
| 			ret = 0; | ||||
| 			goto out; | ||||
| 		} | ||||
| 	} | ||||
| 
 | ||||
| 	/* We have to read the records even if we don't care about the inline info. */ | ||||
| 	while ((record_status = read_addr2line_record(a2l, | ||||
| 						      &record_function, | ||||
| 						      &record_filename, | ||||
| 						      &record_line_nr)) == 1) { | ||||
| 		if (unwind_inlines && node && inline_count++ < MAX_INLINE_NEST) { | ||||
| 			if (inline_list__append_record(dso, node, sym, | ||||
| 						       record_function, | ||||
| 						       record_filename, | ||||
| 						       record_line_nr)) { | ||||
| 				ret = 0; | ||||
| 				goto out; | ||||
| 			} | ||||
| 			ret = 1; /* found at least one inline frame */ | ||||
| 		} | ||||
| 	} | ||||
| 
 | ||||
| out: | ||||
| 	free(record_function); | ||||
| 	free(record_filename); | ||||
| 	return ret; | ||||
| } | ||||
| 
 | ||||
| void dso__free_a2l(struct dso *dso) | ||||
| { | ||||
| 	struct a2l_subprocess *a2l = dso->a2l; | ||||
| 
 | ||||
| 	if (!a2l) | ||||
| 		return; | ||||
| 
 | ||||
| 	addr2line_subprocess_cleanup(a2l); | ||||
| 
 | ||||
| 	dso->a2l = NULL; | ||||
| } | ||||
| 
 | ||||
| #endif /* HAVE_LIBBFD_SUPPORT */ | ||||
| 
 | ||||
| static struct inline_node *addr2inlines(const char *dso_name, u64 addr, | ||||
| 					struct dso *dso, struct symbol *sym) | ||||
| { | ||||
| 	struct inline_node *node; | ||||
| 
 | ||||
| 	node = zalloc(sizeof(*node)); | ||||
| 	if (node == NULL) { | ||||
| 		perror("not enough memory for the inline node"); | ||||
| 		goto out; | ||||
| 		return NULL; | ||||
| 	} | ||||
| 
 | ||||
| 	INIT_LIST_HEAD(&node->val); | ||||
| 	node->addr = addr; | ||||
| 
 | ||||
| 	/* addr2line -f generates two lines for each inlined functions */ | ||||
| 	while (getline(&funcname, &funclen, fp) != -1) { | ||||
| 		char *srcline; | ||||
| 		struct symbol *inline_sym; | ||||
| 
 | ||||
| 		strim(funcname); | ||||
| 
 | ||||
| 		if (getline(&filename, &filelen, fp) == -1) | ||||
| 			goto out; | ||||
| 
 | ||||
| 		if (filename_split(filename, &line_nr) != 1) | ||||
| 			goto out; | ||||
| 
 | ||||
| 		srcline = srcline_from_fileline(filename, line_nr); | ||||
| 		inline_sym = new_inline_sym(dso, sym, funcname); | ||||
| 
 | ||||
| 		if (inline_list__append(inline_sym, srcline, node) != 0) { | ||||
| 			free(srcline); | ||||
| 			if (inline_sym && inline_sym->inlined) | ||||
| 				symbol__delete(inline_sym); | ||||
| 			goto out; | ||||
| 		} | ||||
| 	} | ||||
| 
 | ||||
| out: | ||||
| 	pclose(fp); | ||||
| 	free(filename); | ||||
| 	free(funcname); | ||||
| 
 | ||||
| 	addr2line(dso_name, addr, NULL, NULL, dso, true, node, sym); | ||||
| 	return node; | ||||
| } | ||||
| 
 | ||||
| #endif /* HAVE_LIBBFD_SUPPORT */ | ||||
| 
 | ||||
| /*
 | ||||
|  * Number of addr2line failures (without success) before disabling it for that | ||||
|  * dso. | ||||
|  |  | |||
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	 Tony Garnock-Jones
						Tony Garnock-Jones