From 4112eb1899c0e711b2ab1491f51215359cf94d74 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Fri, 10 Oct 2014 15:55:15 -0300 Subject: [PATCH] perf evlist: Default to syswide target when no thread/cpu maps set If all a tool wants is to do system wide event monitoring, there is no more the need to setup thread_map and cpu_map objects, just call perf_evlist__open() and it will do create one fd per CPU monitoring all threads. Cc: Adrian Hunter Cc: Borislav Petkov Cc: David Ahern Cc: Don Zickus Cc: Frederic Weisbecker Cc: Jean Pihet Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-poovolkigu72brx4783uq4cf@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/evlist.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 5fc7bd42c803..b4b54d84e9b0 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -1175,11 +1175,51 @@ void perf_evlist__close(struct perf_evlist *evlist) } } +static int perf_evlist__create_syswide_maps(struct perf_evlist *evlist) +{ + int err = -ENOMEM; + + /* + * Try reading /sys/devices/system/cpu/online to get + * an all cpus map. + * + * FIXME: -ENOMEM is the best we can do here, the cpu_map + * code needs an overhaul to properly forward the + * error, and we may not want to do that fallback to a + * default cpu identity map :-\ + */ + evlist->cpus = cpu_map__new(NULL); + if (evlist->cpus == NULL) + goto out; + + evlist->threads = thread_map__new_dummy(); + if (evlist->threads == NULL) + goto out_free_cpus; + + err = 0; +out: + return err; +out_free_cpus: + cpu_map__delete(evlist->cpus); + evlist->cpus = NULL; + goto out; +} + int perf_evlist__open(struct perf_evlist *evlist) { struct perf_evsel *evsel; int err; + /* + * Default: one fd per CPU, all threads, aka systemwide + * as sys_perf_event_open(cpu = -1, thread = -1) is EINVAL + */ + if (evlist->threads == NULL && evlist->cpus == NULL) { + err = perf_evlist__create_syswide_maps(evlist); + if (err < 0) + goto out_err; + } + perf_evlist__update_id_pos(evlist); evlist__for_each(evlist, evsel) { -- 2.20.1