The following commit has been merged into the perf/urgent branch of tip:
Commit-ID: 7736627b865defff2430e95df235b4aa2450bc37
Gitweb: https://git.kernel.org/tip/7736627b865defff2430e95df235b4aa2450bc37
Author: Andi Kleen <ak@xxxxxxxxxxxxxxx>
AuthorDate: Wed, 20 Nov 2019 16:15:17 -08:00
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitterDate: Fri, 29 Nov 2019 12:20:45 -03:00
perf stat: Use affinity for closing file descriptors
Closing a perf fd can also trigger an IPI to the target CPU.
Use the same affinity technique as we use for reading/enabling events to
closing to optimize the CPU transitions.
Before on a large test case with 94 CPUs:
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
32.56 3.085463 50 61483 close
After:
10.54 0.735704 11 61485 close
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Link: http://lore.kernel.org/lkml/20191121001522.180827-8-andi@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/evlist.c | 31 +++++++++++++++++++++++++++++--
1 file changed, 29 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index dae6e84..2e8d38a 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -18,6 +18,7 @@
#include "debug.h"
#include "units.h"
#include <internal/lib.h> // page_size
+#include "affinity.h"
#include "../perf.h"
#include "asm/bug.h"
#include "bpf-event.h"
@@ -1169,9 +1170,35 @@ void perf_evlist__set_selected(struct evlist *evlist,
void evlist__close(struct evlist *evlist)
{
struct evsel *evsel;
+ struct affinity affinity;
+ int cpu, i;
- evlist__for_each_entry_reverse(evlist, evsel)
- evsel__close(evsel);
+ /*
+ * With perf record core.cpus is usually NULL.
+ * Use the old method to handle this for now.
+ */
+ if (!evlist->core.cpus) {
+ evlist__for_each_entry_reverse(evlist, evsel)
+ evsel__close(evsel);
+ return;
+ }
+
+ if (affinity__setup(&affinity) < 0)
+ return;
+ evlist__for_each_cpu(evlist, i, cpu) {
+ affinity__set(&affinity, cpu);
+
+ evlist__for_each_entry_reverse(evlist, evsel) {
+ if (evsel__cpu_iter_skip(evsel, cpu))
+ continue;
+ perf_evsel__close_cpu(&evsel->core, evsel->cpu_iter - 1);
+ }
+ }
+ affinity__cleanup(&affinity);
+ evlist__for_each_entry_reverse(evlist, evsel) {
+ perf_evsel__free_fd(&evsel->core);
+ perf_evsel__free_id(&evsel->core);
+ }
}
static int perf_evlist__create_syswide_maps(struct evlist *evlist)
|