From: Yang Jihong Date: Tue, 31 Oct 2023 10:55:23 +0000 (+0000) Subject: perf tools: Add --debug-file option to redirect debug output X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=72108c0b9c0e004d7dfc2fc88b02c30b12711325;p=linux.git perf tools: Add --debug-file option to redirect debug output Currently, debug messages is output to stderr, add --debug-file option to support redirection to a specified file. Some test scenarios: # perf --list-opts --help --version --exec-path --html-path --paginate --no-pager --debugfs-dir --buildid-dir --list-cmds --list-opts --debug --debug-file # perf --debug-file No path given for --debug-file. Usage: perf [--version] [--help] [OPTIONS] COMMAND [ARGS] # perf --debug-file /sys/perf.log record -v true Open debug file '/sys/perf.log' failed: Permission denied Usage: perf [--version] [--help] [OPTIONS] COMMAND [ARGS] # perf --debug-file /tmp/perf.log record -v true [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.013 MB perf.data (26 samples) ] # cat /tmp/perf.log DEBUGINFOD_URLS= Using CPUID GenuineIntel-6-3E-4 nr_cblocks: 0 affinity: SYS mmap flush: 1 comp level: 0 mmap size 528384B Control descriptor is not initialized mmap size 528384B Looking at the vmlinux_path (8 entries long) Using /proc/kcore for kernel data Using /proc/kallsyms for symbols symbol:unmap_start file:(null) line:0 offset:0 return:0 lazy:(null) symbol:unmap_complete file:(null) line:0 offset:0 return:0 lazy:(null) symbol:map_start file:(null) line:0 offset:0 return:0 lazy:(null) symbol:map_complete file:(null) line:0 offset:0 return:0 lazy:(null) symbol:reloc_start file:(null) line:0 offset:0 return:0 lazy:(null) symbol:reloc_complete file:(null) line:0 offset:0 return:0 lazy:(null) symbol:init_start file:(null) line:0 offset:0 return:0 lazy:(null) symbol:init_complete file:(null) line:0 offset:0 return:0 lazy:(null) symbol:lll_lock_wait_private file:(null) line:0 offset:0 return:0 lazy:(null) symbol:lll_lock_wait file:(null) line:0 offset:0 return:0 lazy:(null) symbol:setjmp file:(null) line:0 offset:0 return:0 lazy:(null) symbol:longjmp file:(null) line:0 offset:0 return:0 lazy:(null) symbol:longjmp_target file:(null) line:0 offset:0 return:0 lazy:(null) failed to write feature HYBRID_TOPOLOGY Signed-off-by: Yang Jihong Acked-by: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20231031105523.1472558-1-yangjihong1@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/perf/Documentation/perf.txt b/tools/perf/Documentation/perf.txt index ba3df49c169d3..a7cf7bc2f9689 100644 --- a/tools/perf/Documentation/perf.txt +++ b/tools/perf/Documentation/perf.txt @@ -64,6 +64,9 @@ OPTIONS perf-event-open - Print perf_event_open() arguments and return value +--debug-file:: + Write debug output to a specified file. + DESCRIPTION ----------- Performance counters for Linux are a new kernel-based subsystem diff --git a/tools/perf/perf.c b/tools/perf/perf.c index d3fc8090413c8..921bee0a64370 100644 --- a/tools/perf/perf.c +++ b/tools/perf/perf.c @@ -39,6 +39,7 @@ #include static int use_pager = -1; +static FILE *debug_fp = NULL; struct cmd_struct { const char *cmd; @@ -162,6 +163,19 @@ static void commit_pager_choice(void) } } +static int set_debug_file(const char *path) +{ + debug_fp = fopen(path, "w"); + if (!debug_fp) { + fprintf(stderr, "Open debug file '%s' failed: %s\n", + path, strerror(errno)); + return -1; + } + + debug_set_file(debug_fp); + return 0; +} + struct option options[] = { OPT_ARGUMENT("help", "help"), OPT_ARGUMENT("version", "version"), @@ -174,6 +188,7 @@ struct option options[] = { OPT_ARGUMENT("list-cmds", "list-cmds"), OPT_ARGUMENT("list-opts", "list-opts"), OPT_ARGUMENT("debug", "debug"), + OPT_ARGUMENT("debug-file", "debug-file"), OPT_END() }; @@ -287,6 +302,18 @@ static int handle_options(const char ***argv, int *argc, int *envchanged) (*argv)++; (*argc)--; + } else if (!strcmp(cmd, "--debug-file")) { + if (*argc < 2) { + fprintf(stderr, "No path given for --debug-file.\n"); + usage(perf_usage_string); + } + + if (set_debug_file((*argv)[1])) + usage(perf_usage_string); + + (*argv)++; + (*argc)--; + } else { fprintf(stderr, "Unknown option: %s\n", cmd); usage(perf_usage_string); @@ -547,5 +574,8 @@ int main(int argc, const char **argv) fprintf(stderr, "Failed to run command '%s': %s\n", cmd, str_error_r(errno, sbuf, sizeof(sbuf))); out: + if (debug_fp) + fclose(debug_fp); + return 1; }