Re: [PATCH 05/23] perf tests: Add simple session read/write test

[Jiri Olsa <jolsa@redhat.com>]

On Wed, Jul 17, 2013 at 04:33:13PM -0300, Arnaldo Carvalho de Melo wrote:
> Em Wed, Jul 17, 2013 at 07:49:45PM +0200, Jiri Olsa escreveu:
> > +static struct perf_evlist *get_evlist(void)
> > +{
> > +	int err;
> > +	struct perf_evlist *evlist = perf_evlist__new();
> > +	if (evlist == NULL) {
> > +		pr_err("perf_evlist__new failed\n");
> > +		return NULL;
> > +	}
> > +	err = perf_evlist__add_default(evlist);
> > +	if (err < 0) {
> > +		pr_err("Not enough memory to create evsel\n");
> > +		perf_evlist__delete(evlist);
> > +		evlist = NULL;
> > +	}
> > +	return evlist;
> > +}
> 
> I think the above can be such a common idiom that having a new
> constructor for it is doable, i.e.:
> 
> 	evlist = perf_evlist__new_default(void);
> 	if (evlist == NULL)
> 		pr_debug, etc

ook

> 
> > +
> > +static union perf_event *get_event_MMAP(void)
> > +{
> > +	static union perf_event event;
> > +	size_t size;
> > +
> > +	size = snprintf(event.mmap.filename, sizeof(event.mmap.filename),
> > +			"krava") + 1;
> > +	size = PERF_ALIGN(size, sizeof(u64));
> > +
> > +	event.header.type = PERF_RECORD_MMAP;
> > +	event.header.misc = PERF_RECORD_MISC_KERNEL;
> > +	event.header.size = sizeof(event.mmap) -
> > +			    (sizeof(event.mmap.filename) - size);
> > +
> > +	event.mmap.pgoff = 10;
> > +	event.mmap.start = 0;
> > +	event.mmap.len   = 10;
> > +	event.mmap.pid   = 123;
> > +
> > +	return &event;
> > +}
> 
> Don't use statics, here perhaps we can have another general purpose
> helper:
> 
> 	void perf_event__init_mmap(union perf_event *event)
> 
> We then could use it on the synthesizing routines, etc.

ook

> 

SNIP

> > +
> > +static int store_event(int fd, union perf_event *event, size_t *size)
> > +{
> > +	*size += event->header.size;
> > +	return write(fd, event, event->header.size) > 0 ? 0 : -1;
> > +}
> 
> 	I think we need a writen like we have readn and then do it like:
> 
> 	return writen(fd, event, event->header.size) == event->header.size ? 0 : -1;

hum, we could generalize write_output function from builtin-record

> 
> ?
> 

SNIP

> > +
> > +	TEST_ASSERT_VAL("failed to write header",
> > +		!perf_session__write_header(session, evlist, fd, true));
> 
> Humm, can't perf_session__write_header use session->fd? Just like you
> did for some other routines in previous patches in this series?

right, but need to check if the builtin-inject caller uses the same fd

thanks,
jirka