When in TUI mode, it is impossible to show all the debug messages to console. This make it hard to debug perf issues using debug messages. This patch adds support for logging debug messages to file to resolve this problem.
The usage is: perf -debug verbose=2 --debug file=1 COMMAND And the path of log file is '~/perf.log'. Signed-off-by: Changbin Du <[email protected]> --- tools/perf/Documentation/perf.txt | 4 +++- tools/perf/util/debug.c | 20 ++++++++++++++++++++ 2 files changed, 23 insertions(+), 1 deletion(-) diff --git a/tools/perf/Documentation/perf.txt b/tools/perf/Documentation/perf.txt index 401f0ed67439..45db7b22d1a5 100644 --- a/tools/perf/Documentation/perf.txt +++ b/tools/perf/Documentation/perf.txt @@ -16,7 +16,8 @@ OPTIONS Setup debug variable (see list below) in value range (0, 10). Use like: --debug verbose # sets verbose = 1 - --debug verbose=2 # sets verbose = 2 + --debug verbose=2 --debug file=1 + # sets verbose = 2 and save log to file List of debug variables allowed to set: verbose - general debug messages @@ -24,6 +25,7 @@ OPTIONS data-convert - data convert command debug messages stderr - write debug output (option -v) to stderr in browser mode + file - write debug output to log file ~/perf.log --buildid-dir:: Setup buildid cache directory. It has higher priority than diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c index 3780fe42453b..f0b4346a0efa 100644 --- a/tools/perf/util/debug.c +++ b/tools/perf/util/debug.c @@ -8,6 +8,7 @@ #include <stdarg.h> #include <stdio.h> #include <stdlib.h> +#include <errno.h> #include <sys/wait.h> #include <api/debug.h> #include <linux/time64.h> @@ -28,6 +29,8 @@ int verbose; bool dump_trace = false, quiet = false; int debug_ordered_events; static int redirect_to_stderr; +static int log_to_file; +static FILE *log_file; int debug_data_convert; int veprintf(int level, int var, const char *fmt, va_list args) @@ -39,6 +42,9 @@ int veprintf(int level, int var, const char *fmt, va_list args) ui_helpline__vshow(fmt, args); else ret = vfprintf(stderr, fmt, args); + + if (log_file) + vfprintf(log_file, fmt, args); } return ret; @@ -180,6 +186,7 @@ static struct debug_variable { { .name = "verbose", .ptr = &verbose }, { .name = "ordered-events", .ptr = &debug_ordered_events}, { .name = "stderr", .ptr = &redirect_to_stderr}, + { .name = "file", .ptr = &log_to_file}, { .name = "data-convert", .ptr = &debug_data_convert }, { .name = NULL, } }; @@ -219,6 +226,19 @@ int perf_debug_option(const char *str) v = -1; *var->ptr = v; + + if (log_to_file) { + char log_path[PATH_MAX]; + + strcat(strcpy(log_path, getenv("HOME")), "/perf.log"); + log_file = fopen(log_path, "a"); + if (!log_file) { + pr_err("Can not create log file: %s\n", strerror(errno)); + free(s); + return -1; + } + } + free(s); return 0; } -- 2.20.1
