perf: Make -f the default for perf record

Force the overwriting mode by default if append mode is not explicit.
Adding -f every time one uses perf on a daily basis quickly becomes a
burden.

Keep the -f among the options though to avoid breaking some random
users scripts.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>

diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index fc46c0b..b29bd2d 100644 (file)
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -58,7 +58,7 @@ OPTIONS
 
 -f::
 --force::
-       Overwrite existing data file.
+       Overwrite existing data file. (deprecated)
 
 -c::
 --count=::

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 9a95136..dcda899 100644 (file)
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -26,6 +26,11 @@
 #include <unistd.h>
 #include <sched.h>
 
+enum write_mode_t {
+       WRITE_FORCE,
+       WRITE_APPEND
+};
+
 static int                     *fd[MAX_NR_CPUS][MAX_COUNTERS];
 
 static long                    default_interval                =      0;
@@ -47,8 +52,7 @@ static pid_t                  *all_tids                       =      NULL;
 static int                     thread_num                      =      0;
 static pid_t                   child_pid                       =     -1;
 static bool                    inherit                         =   true;
-static bool                    force                           =  false;
-static bool                    append_file                     =  false;
+static enum write_mode_t       write_mode                      = WRITE_FORCE;
 static bool                    call_graph                      =  false;
 static bool                    inherit_stat                    =  false;
 static bool                    no_samples                      =  false;
@@ -450,26 +454,19 @@ static int __cmd_record(int argc, const char **argv)
        }
 
        if (!stat(output_name, &st) && st.st_size) {
-               if (!force) {
-                       if (!append_file) {
-                               pr_err("Error, output file %s exists, use -A "
-                                      "to append or -f to overwrite.\n",
-                                      output_name);
-                               exit(-1);
-                       }
-               } else {
+               if (write_mode == WRITE_FORCE) {
                        char oldname[PATH_MAX];
                        snprintf(oldname, sizeof(oldname), "%s.old",
                                 output_name);
                        unlink(oldname);
                        rename(output_name, oldname);
                }
-       } else {
-               append_file = false;
+       } else if (write_mode == WRITE_APPEND) {
+               write_mode = WRITE_FORCE;
        }
 
        flags = O_CREAT|O_RDWR;
-       if (append_file)
+       if (write_mode == WRITE_APPEND)
                file_new = 0;
        else
                flags |= O_TRUNC;
@@ -480,7 +477,8 @@ static int __cmd_record(int argc, const char **argv)
                exit(-1);
        }
 
-       session = perf_session__new(output_name, O_WRONLY, force);
+       session = perf_session__new(output_name, O_WRONLY,
+                                   write_mode == WRITE_FORCE);
        if (session == NULL) {
                pr_err("Not enough memory for reading perf file header\n");
                return -1;
@@ -667,6 +665,8 @@ static const char * const record_usage[] = {
        NULL
 };
 
+static bool force, append_file;
+
 static const struct option options[] = {
        OPT_CALLBACK('e', "event", NULL, "event",
                     "event selector. use 'perf list' to list available events",
@@ -688,7 +688,7 @@ static const struct option options[] = {
        OPT_INTEGER('C', "profile_cpu", &profile_cpu,
                            "CPU to profile on"),
        OPT_BOOLEAN('f', "force", &force,
-                       "overwrite existing data file"),
+                       "overwrite existing data file (deprecated)"),
        OPT_LONG('c', "count", &default_interval,
                    "event period to sample"),
        OPT_STRING('o', "output", &output_name, "file",
@@ -725,6 +725,16 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
                !system_wide && profile_cpu == -1)
                usage_with_options(record_usage, options);
 
+       if (force && append_file) {
+               fprintf(stderr, "Can't overwrite and append at the same time."
+                               " You need to choose between -f and -A");
+               usage_with_options(record_usage, options);
+       } else if (append_file) {
+               write_mode = WRITE_APPEND;
+       } else {
+               write_mode = WRITE_FORCE;
+       }
+
        symbol__init();
 
        if (!nr_counters) {