Re: [PATCH 05/11] perf tools: Move tracing_path stuff under same namespace

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Wed, Aug 26, 2015 at 04:48:36PM +0200, Jiri Olsa escreveu:
> On Wed, Aug 26, 2015 at 11:42:11AM -0300, Arnaldo Carvalho de Melo wrote:
> > Em Wed, Aug 26, 2015 at 03:46:47PM +0200, Jiri Olsa escreveu:
> > > Renaming all functions touching tracing_path under same
> > > namespace. New interface is:
> > 
> > But we were trying to have debugfs stuff in tools/lib/api/fs/, so that
> > it could eventually be used by some other tools, etc, and now we're
> > going the other way around, de-librarifying, not good :-\
> 
> well this gathers tracefs/debugfs together, the api/fs/{trace|debug}fs
> are just building blocks
> 
> I only moved the debugfs__strerror_open_tp out of the debugfs object
> because it needs to be one layer up, because it needs to touch tracefs
> as well

Why not leave it there, since, for historical reasons, what is tracefs
now was something implemented inside debugfs, so having that special
case in debugfs__strerror_open_tp():

                if (!access(debugfs_mountpoint, R_OK) && strncmp(filename, "tracing/", 8) == 0) {

Is ok, since tools will need to deal with older kernels, etc.

But ok, I see your point, we should rename it to something like
tracepoint__strerror_open_definition(), so as to detach this from
"debugfs" _and_ "tracefs", pseudo-filesystem based DWARF-like stuff
(event definitions), but then why not have that somewhere in
tools/lib/api/tracepoint/.

Or was it the difficulty in getting this nicely namespaced what made
you get it back to tools/perf/util/?

I can have some empathy for that, if that is the case ;-\

- Arnaldo
 
> > 
> > - Arnaldo
> >  
> > >   char tracing_path[];
> > >   char tracing_events_path[];
> > >   - tracing mount
> > > 
> > >   void perf_tracing_path_set(const char *mountpoint);
> > >   - setting directly tracing_path(_events), used by --debugfs-dir option
> > > 
> > >   const char *perf_tracing_path_mount(const char *mountpoint);
> > >   - initial setup of tracing_path(_events), called from perf.c
> > > 
> > >   int tracing_path_strerror_open(int err, char *buf, size_t size, const char *filename);
> > >   int tracing_path_strerror_open_tp(int err, char *buf, size_t size, const char *sys, const char *name);
> > >   - strerror functions to get error string when failing to open
> > >     tracepoint files
> > > 
> > >   char *get_tracing_file(const char *name);
> > >   void put_tracing_file(char *file);
> > >   - get/put tracing file path
> > > 
> > > Link: http://lkml.kernel.org/n/tip-miy6kftxxryjf40b3qb6eknc@git.kernel.org
> > > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> > > ---
> > >  tools/perf/builtin-trace.c |  4 ++--
> > >  tools/perf/perf.c          |  8 ++++----
> > >  tools/perf/util/util.c     | 26 +++++++++++++-------------
> > >  tools/perf/util/util.h     |  8 ++++----
> > >  4 files changed, 23 insertions(+), 23 deletions(-)
> > > 
> > > diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
> > > index 2f1162daa3c5..384ebe32698a 100644
> > > --- a/tools/perf/builtin-trace.c
> > > +++ b/tools/perf/builtin-trace.c
> > > @@ -2667,11 +2667,11 @@ out_delete_evlist:
> > >  	char errbuf[BUFSIZ];
> > >  
> > >  out_error_sched_stat_runtime:
> > > -	debugfs__strerror_open_tp(errno, errbuf, sizeof(errbuf), "sched", "sched_stat_runtime");
> > > +	tracing_path_strerror_open_tp(errno, errbuf, sizeof(errbuf), "sched", "sched_stat_runtime");
> > >  	goto out_error;
> > >  
> > >  out_error_raw_syscalls:
> > > -	debugfs__strerror_open_tp(errno, errbuf, sizeof(errbuf), "raw_syscalls", "sys_(enter|exit)");
> > > +	tracing_path_strerror_open_tp(errno, errbuf, sizeof(errbuf), "raw_syscalls", "sys_(enter|exit)");
> > >  	goto out_error;
> > >  
> > >  out_error_mmap:
> > > diff --git a/tools/perf/perf.c b/tools/perf/perf.c
> > > index 07dbff5c0e60..c5acdadde347 100644
> > > --- a/tools/perf/perf.c
> > > +++ b/tools/perf/perf.c
> > > @@ -214,7 +214,7 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
> > >  				fprintf(stderr, "No directory given for --debugfs-dir.\n");
> > >  				usage(perf_usage_string);
> > >  			}
> > > -			perf_debugfs_set_path((*argv)[1]);
> > > +			perf_tracing_path_set((*argv)[1]);
> > >  			if (envchanged)
> > >  				*envchanged = 1;
> > >  			(*argv)++;
> > > @@ -230,7 +230,7 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
> > >  			(*argv)++;
> > >  			(*argc)--;
> > >  		} else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
> > > -			perf_debugfs_set_path(cmd + strlen(CMD_DEBUGFS_DIR));
> > > +			perf_tracing_path_set(cmd + strlen(CMD_DEBUGFS_DIR));
> > >  			fprintf(stderr, "dir: %s\n", tracing_path);
> > >  			if (envchanged)
> > >  				*envchanged = 1;
> > > @@ -517,8 +517,8 @@ int main(int argc, const char **argv)
> > >  	cmd = perf_extract_argv0_path(argv[0]);
> > >  	if (!cmd)
> > >  		cmd = "perf-help";
> > > -	/* get debugfs mount point from /proc/mounts */
> > > -	perf_debugfs_mount(NULL);
> > > +	/* get debugfs/tracefs mount point from /proc/mounts */
> > > +	perf_tracing_path_mount(NULL);
> > >  	/*
> > >  	 * "perf-xxxx" is the same as "perf xxxx", but we obviously:
> > >  	 *
> > > diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
> > > index 03d1d74a5ede..675d112a887d 100644
> > > --- a/tools/perf/util/util.c
> > > +++ b/tools/perf/util/util.c
> > > @@ -390,7 +390,7 @@ void set_term_quiet_input(struct termios *old)
> > >  	tcsetattr(0, TCSANOW, &tc);
> > >  }
> > >  
> > > -static void set_tracing_events_path(const char *tracing, const char *mountpoint)
> > > +static void tracing_path_set(const char *tracing, const char *mountpoint)
> > >  {
> > >  	snprintf(tracing_path, sizeof(tracing_path), "%s/%s",
> > >  		 mountpoint, tracing);
> > > @@ -398,7 +398,7 @@ static void set_tracing_events_path(const char *tracing, const char *mountpoint)
> > >  		 mountpoint, tracing, "events");
> > >  }
> > >  
> > > -static const char *__perf_tracefs_mount(const char *mountpoint)
> > > +static const char *tracing_path_tracefs_mount(const char *mountpoint)
> > >  {
> > >  	const char *mnt;
> > >  
> > > @@ -406,12 +406,12 @@ static const char *__perf_tracefs_mount(const char *mountpoint)
> > >  	if (!mnt)
> > >  		return NULL;
> > >  
> > > -	set_tracing_events_path("", mnt);
> > > +	tracing_path_set("", mnt);
> > >  
> > >  	return mnt;
> > >  }
> > >  
> > > -static const char *__perf_debugfs_mount(const char *mountpoint)
> > > +static const char *tracing_path_debugfs_mount(const char *mountpoint)
> > >  {
> > >  	const char *mnt;
> > >  
> > > @@ -419,30 +419,30 @@ static const char *__perf_debugfs_mount(const char *mountpoint)
> > >  	if (!mnt)
> > >  		return NULL;
> > >  
> > > -	set_tracing_events_path("tracing/", mnt);
> > > +	tracing_path_set("tracing/", mnt);
> > >  
> > >  	return mnt;
> > >  }
> > >  
> > > -const char *perf_debugfs_mount(const char *mountpoint)
> > > +const char *perf_tracing_path_mount(const char *mountpoint)
> > >  {
> > >  	const char *mnt;
> > >  
> > > -	mnt = __perf_tracefs_mount(mountpoint);
> > > +	mnt = tracing_path_tracefs_mount(mountpoint);
> > >  	if (mnt)
> > >  		return mnt;
> > >  
> > > -	mnt = __perf_debugfs_mount(mountpoint);
> > > +	mnt = tracing_path_debugfs_mount(mountpoint);
> > >  
> > >  	return mnt;
> > >  }
> > >  
> > > -void perf_debugfs_set_path(const char *mntpt)
> > > +void perf_tracing_path_set(const char *mntpt)
> > >  {
> > > -	set_tracing_events_path("tracing/", mntpt);
> > > +	tracing_path_set("tracing/", mntpt);
> > >  }
> > >  
> > > -int debugfs__strerror_open(int err, char *buf, size_t size, const char *filename)
> > > +int tracing_path_strerror_open(int err, char *buf, size_t size, const char *filename)
> > >  {
> > >  	char sbuf[128];
> > >  
> > > @@ -485,13 +485,13 @@ int debugfs__strerror_open(int err, char *buf, size_t size, const char *filename
> > >  	return 0;
> > >  }
> > >  
> > > -int debugfs__strerror_open_tp(int err, char *buf, size_t size, const char *sys, const char *name)
> > > +int tracing_path_strerror_open_tp(int err, char *buf, size_t size, const char *sys, const char *name)
> > >  {
> > >  	char path[PATH_MAX];
> > >  
> > >  	snprintf(path, PATH_MAX, "tracing/events/%s/%s", sys, name ?: "*");
> > >  
> > > -	return debugfs__strerror_open(err, buf, size, path);
> > > +	return tracing_path_strerror_open(err, buf, size, path);
> > >  }
> > >  
> > >  char *get_tracing_file(const char *name)
> > > diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
> > > index da48c00ab0db..34a68faf53fe 100644
> > > --- a/tools/perf/util/util.h
> > > +++ b/tools/perf/util/util.h
> > > @@ -85,10 +85,10 @@ extern const char *graph_dotted_line;
> > >  extern char buildid_dir[];
> > >  extern char tracing_path[];
> > >  extern char tracing_events_path[];
> > > -extern void perf_debugfs_set_path(const char *mountpoint);
> > > -const char *perf_debugfs_mount(const char *mountpoint);
> > > -int debugfs__strerror_open(int err, char *buf, size_t size, const char *filename);
> > > -int debugfs__strerror_open_tp(int err, char *buf, size_t size, const char *sys, const char *name);
> > > +extern void perf_tracing_path_set(const char *mountpoint);
> > > +const char *perf_tracing_path_mount(const char *mountpoint);
> > > +int tracing_path_strerror_open(int err, char *buf, size_t size, const char *filename);
> > > +int tracing_path_strerror_open_tp(int err, char *buf, size_t size, const char *sys, const char *name);
> > >  char *get_tracing_file(const char *name);
> > >  void put_tracing_file(char *file);
> > >  
> > > -- 
> > > 2.4.3