lkml.org 
[lkml]   [2019]   [Nov]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v5 07/13] perf stat: Use affinity for closing file descriptors
Date
From: Andi Kleen <ak@linux.intel.com>

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@linux.intel.com>

---

v2: Use new iterator macros
v3: Use new iterator macros
Add missing affinity__cleanup
v4:
Update iterators again
---
tools/perf/util/evlist.c | 27 +++++++++++++++++++++++++--
1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index dae6e846b2f8..0dcea66329e2 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 +1170,31 @@ 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);
+ 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)
--
2.23.0

\
 
 \ /
  Last update: 2019-11-07 19:17    [W:0.234 / U:0.160 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site