Re: [PATCH v5 1/6] perf tools: Derive trigger class from auxtrace_snapshot

[Jiri Olsa]

On Mon, Apr 18, 2016 at 02:55:27PM +0000, Wang Nan wrote:

SNIP

> -static volatile int auxtrace_snapshot_err;
>  static volatile int auxtrace_record__snapshot_started;
> +static DEFINE_TRIGGER(auxtrace_snapshot);
>  
>  static void sig_handler(int sig)
>  {
> @@ -282,11 +247,12 @@ static void record__read_auxtrace_snapshot(struct 
> record *rec)
>  {
>       pr_debug("Recording AUX area tracing snapshot\n");
>       if (record__auxtrace_read_snapshot_all(rec) < 0) {
> -             auxtrace_snapshot_err = -1;
> +             auxtrace_snapshot_error();
>       } else {
> -             auxtrace_snapshot_err = 
> auxtrace_record__snapshot_finish(rec->itr);
> -             if (!auxtrace_snapshot_err)
> -                     auxtrace_snapshot_enable();
> +             if (auxtrace_record__snapshot_finish(rec->itr))
> +                     auxtrace_snapshot_error();
> +             else
> +                     auxtrace_snapshot_ready();
>       }
>  }
>  
> @@ -815,21 +781,21 @@ static int __cmd_record(struct record *rec, int argc, 
> const char **argv)
>               perf_evlist__enable(rec->evlist);
>       }
>  
> -     auxtrace_snapshot_enable();
> +     auxtrace_snapshot_ready();
>       for (;;) {
>               unsigned long long hits = rec->samples;
>  
>               if (record__mmap_read_all(rec) < 0) {
> -                     auxtrace_snapshot_disable();
> +                     auxtrace_snapshot_error();
>                       err = -1;
>                       goto out_child;
>               }
>  
>               if (auxtrace_record__snapshot_started) {
>                       auxtrace_record__snapshot_started = 0;

I'm ok with the chenge, however what I wanted to understand
is why we need auxtrace_record__snapshot_started ;-)

could we get rid of it like in the patch below?

thanks,
jirka


---
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index ad37f6937410..e220bd5eea0e 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -128,7 +128,6 @@ static volatile int done;
 static volatile int signr = -1;
 static volatile int child_finished;
 
-static volatile int auxtrace_record__snapshot_started;
 static DEFINE_TRIGGER(auxtrace_snapshot);
 
 static void sig_handler(int sig)
@@ -791,8 +790,7 @@ static int __cmd_record(struct record *rec, int argc, const 
char **argv)
                        goto out_child;
                }
 
-               if (auxtrace_record__snapshot_started) {
-                       auxtrace_record__snapshot_started = 0;
+               if (auxtrace_snapshot_is_toggled()) {
                        if (!auxtrace_snapshot_is_error())
                                record__read_auxtrace_snapshot(rec);
                        if (auxtrace_snapshot_is_error()) {
@@ -1416,7 +1414,6 @@ static void snapshot_sig_handler(int sig __maybe_unused)
        if (!auxtrace_snapshot_is_ready())
                return;
        auxtrace_snapshot_toggle();
-       auxtrace_record__snapshot_started = 1;
        if (auxtrace_record__snapshot_start(record.itr))
                auxtrace_snapshot_error();
 }