From be8ecc57f180415e8a7c1cc5620c5236be2a7e56 Mon Sep 17 00:00:00 2001 From: Tony Garnock-Jones Date: Thu, 16 Sep 2021 14:09:39 +0200 Subject: [PATCH] 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 Tested-by: Ian Rogers Cc: Ingo Molnar Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20210916120939.453536-1-tonyg@leastfixedpoint.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/srcline.c | 338 ++++++++++++++++++++++++++++++++++------------ 1 file changed, 250 insertions(+), 88 deletions(-) diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c index 5b7d6c1..af468e3 100644 --- a/tools/perf/util/srcline.c +++ b/tools/perf/util/srcline.c @@ -1,8 +1,10 @@ // SPDX-License-Identifier: GPL-2.0 #include +#include #include #include #include +#include #include #include @@ -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; + if (a2l->addr2line.pid != -1) { + kill(a2l->addr2line.pid, SIGKILL); + finish_command(&a2l->addr2line); /* ignore result, we don't care */ + a2l->addr2line.pid = -1; + } - scnprintf(cmd, sizeof(cmd), "addr2line -e %s %016"PRIx64, - dso_name, addr); + if (a2l->to_child != NULL) { + fclose(a2l->to_child); + a2l->to_child = NULL; + } - fp = popen(cmd, "r"); - if (fp == NULL) { - pr_warning("popen failed for %s\n", dso_name); - return 0; + 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; } - if (getline(&filename, &len, fp) < 0 || !len) { - pr_warning("addr2line has no output for %s\n", dso_name); + 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; } - ret = filename_split(filename, line_nr); - if (ret != 1) { - free(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; } - *file = filename; + return a2l; out: - pclose(fp); - return ret; + if (a2l) + addr2line_subprocess_cleanup(a2l); + + return NULL; } -void dso__free_a2l(struct dso *dso __maybe_unused) +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; } -static struct inline_node *addr2inlines(const char *dso_name, u64 addr, - struct dso *dso __maybe_unused, - struct symbol *sym) +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) { - 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 symbol *inline_sym = new_inline_sym(dso, sym, function); - scnprintf(cmd, sizeof(cmd), "addr2line -e %s -i -f %016"PRIx64, - dso_name, addr); + return inline_list__append(inline_sym, srcline_from_fileline(filename, line_nr), node); +} - fp = popen(cmd, "r"); - if (fp == NULL) { - pr_err("popen failed for %s\n", dso_name); - return NULL; +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) +{ + 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; + + if (!a2l) { + dso->a2l = addr2line_subprocess_init(dso_name); + a2l = dso->a2l; } - node = zalloc(sizeof(*node)); - if (node == NULL) { - perror("not enough memory for the inline node"); + if (a2l == NULL) { + if (!symbol_conf.disable_add2line_warn) + pr_warning("%s %s: addr2line_subprocess_init failed\n", __func__, dso_name); goto out; } - 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; + /* + * 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; + } - strim(funcname); + 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 (getline(&filename, &filelen, fp) == -1) - goto out; + if (file) { + *file = strdup(record_filename); + ret = 1; + } + if (line_nr) + *line_nr = record_line_nr; - if (filename_split(filename, &line_nr) != 1) + if (unwind_inlines) { + if (node && inline_list__append_record(dso, node, sym, + record_function, + record_filename, + record_line_nr)) { + ret = 0; 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; + /* 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: - pclose(fp); - free(filename); - free(funcname); + free(record_function); + free(record_filename); + return ret; +} - return node; +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"); + return NULL; + } + + INIT_LIST_HEAD(&node->val); + node->addr = addr; + + addr2line(dso_name, addr, NULL, NULL, dso, true, node, sym); + return node; +} + /* * Number of addr2line failures (without success) before disabling it for that * dso. -- 2.7.4