Re: [PATCH 2/3] perf: Remove dead code in buildin-record.c

Peter Zijlstra
2010-06-25T14:49:04Z

On Fri, 2010-06-25 at 10:13 -0300, Arnaldo Carvalho de Melo wrote:
> Em Fri, Jun 25, 2010 at 10:16:59AM +0800, Gui Jianfeng escreveu:
> > group_fd related code is dead here, remove them.
>
> I agree it is dead at the moment, but I think Peter (or was it Ingo at
> the time?) had a reason for it to live, Peter, care to take a look?

Ah, yes, it would be nice for SH (which doesn't have a PMI) to couple a
software timer with their hardware counter to get samples.

Never got around to actually implementing that though, maybe Paul has a
minion interested in making that work?

> > Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
> > ---
> > tools/perf/builtin-record.c | 12 +-----------
> > 1 files changed, 1 insertions(+), 11 deletions(-)
> >
> > diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> > index abaf0f8..84d58b7 100644
> > --- a/tools/perf/builtin-record.c
> > +++ b/tools/perf/builtin-record.c
> > @@ -45,7 +45,6 @@ static int freq = 1000;
> > static int output;
> > static int pipe_output = 0;
> > static const char *output_name = "perf.data";
> > -static int group = 0;
> > static int realtime_prio = 0;
> > static bool raw_samples = false;
> > static bool system_wide = false;
> > @@ -203,8 +202,6 @@ static void sig_atexit(void)
> > kill(getpid(), signr);
> > }
> >
> > -static int group_fd;
> > -
> > static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int nr)
> > {
> > struct perf_header_attr *h_attr;
> > @@ -291,7 +288,7 @@ static void create_counter(int counter, int cpu)
> > for (thread_index = 0; thread_index < thread_num; thread_index++) {
> > try_again:
> > fd[nr_cpu][counter][thread_index] = sys_perf_event_open(attr,
> > - all_tids[thread_index], cpu, group_fd, 0);
> > + all_tids[thread_index], cpu, -1, 0);
> >
> > if (fd[nr_cpu][counter][thread_index] < 0) {
> > int err = errno;
> > @@ -359,12 +356,6 @@ try_again:
> > assert(fd[nr_cpu][counter][thread_index] >= 0);
> > fcntl(fd[nr_cpu][counter][thread_index], F_SETFL, O_NONBLOCK);
> >
> > - /*
> > - * First counter acts as the group leader:
> > - */
> > - if (group && group_fd == -1)
> > - group_fd = fd[nr_cpu][counter][thread_index];
> > -
> > if (counter || thread_index) {
> > ret = ioctl(fd[nr_cpu][counter][thread_index],
> > PERF_EVENT_IOC_SET_OUTPUT,
> > @@ -406,7 +397,6 @@ static void open_counters(int cpu)
> > {
> > int counter;
> >
> > - group_fd = -1;
> > for (counter = 0; counter < nr_counters; counter++)
> > create_counter(counter, cpu);
> >
> > -- 1.6.5.2