Messages in this thread | | | Date | Wed, 7 Jul 2021 14:43:07 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 6/7] libperF: Add group support to perf_evsel__open |
| |
Em Tue, Jul 06, 2021 at 05:17:03PM +0200, Jiri Olsa escreveu: > Adding support to set group_fd in perf_evsel__open > call and make it to follow the group setup. > > Signed-off-by: Jiri Olsa <jolsa@kernel.org> > --- > tools/lib/perf/evsel.c | 26 ++++++++++++++++++++++++-- > 1 file changed, 24 insertions(+), 2 deletions(-) > > diff --git a/tools/lib/perf/evsel.c b/tools/lib/perf/evsel.c > index 3e6638d27c45..9ebf7122d476 100644 > --- a/tools/lib/perf/evsel.c > +++ b/tools/lib/perf/evsel.c > @@ -17,6 +17,7 @@ > #include <linux/string.h> > #include <sys/ioctl.h> > #include <sys/mman.h> > +#include <asm/bug.h> > > void perf_evsel__init(struct perf_evsel *evsel, struct perf_event_attr *attr, > int idx) > @@ -76,6 +77,25 @@ sys_perf_event_open(struct perf_event_attr *attr, > return syscall(__NR_perf_event_open, attr, pid, cpu, group_fd, flags); > } > > +static int get_group_fd(struct perf_evsel *evsel, int cpu, int thread) > +{ > + struct perf_evsel *leader = evsel->leader; > + int fd; > + > + if (evsel == leader) > + return -1; > + > + /* > + * Leader must be already processed/open, > + * if not it's a bug. > + */ > + BUG_ON(!leader->fd);
Humm, having panics in library code looks ugly, why can't we just return some errno and let the whatever is using the library to fail gracefully?
I applied the patches so far, will make them available at tmp.perf/core now.
- Arnaldo
> + fd = FD(leader, cpu, thread); > + BUG_ON(fd == -1); > + return fd; > +} > + > int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus, > struct perf_thread_map *threads) > { > @@ -111,11 +131,13 @@ int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus, > > for (cpu = 0; cpu < cpus->nr; cpu++) { > for (thread = 0; thread < threads->nr; thread++) { > - int fd; > + int fd, group_fd; > + > + group_fd = get_group_fd(evsel, cpu, thread); > > fd = sys_perf_event_open(&evsel->attr, > threads->map[thread].pid, > - cpus->map[cpu], -1, 0); > + cpus->map[cpu], group_fd, 0); > > if (fd < 0) > return -errno; > -- > 2.31.1 >
--
- Arnaldo
| |