[PATCH 06/13] perf top: Cache the cpu topology info when "-s socket" is used

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

From: Arnaldo Carvalho de Melo <acme@redhat.com>

We need to cache that info to use in perf_event__preprocess_sample(), so
that we don't read sysfs files for each sample.

The next patches will add machine->env pointer that will point to either
the perf_env read from a perf.data file header or from the current
system.

Tools needing some specific info should call the perf_env methods that
cache the info, in this case perf_env__read_cpu_topology_map().

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-54vvsb71b56v9d2e4qxwp49t@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-top.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index e5ca6848f01d..bdaf44f24d5d 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -963,6 +963,13 @@ static int __cmd_top(struct perf_top *top)
 
 	machine__synthesize_threads(&top->session->machines.host, &opts->target,
 				    top->evlist->threads, false, opts->proc_map_timeout);
+
+	if (sort__has_socket) {
+		ret = perf_env__read_cpu_topology_map(&perf_env);
+		if (ret < 0)
+			goto out_err_cpu_topo;
+	}
+
 	ret = perf_top__start_counters(top);
 	if (ret)
 		goto out_delete;
@@ -1020,6 +1027,14 @@ out_delete:
 	top->session = NULL;
 
 	return ret;
+
+out_err_cpu_topo: {
+	char errbuf[BUFSIZ];
+	const char *err = strerror_r(-ret, errbuf, sizeof(errbuf));
+
+	ui__error("Could not read the CPU topology map: %s\n", err);
+	goto out_delete;
+}
 }
 
 static int
-- 
2.1.0