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From: Andi Kleen <andi@firstfloor.org>
To: acme@kernel.org
Cc: jolsa@kernel.org, linux-kernel@vger.kernel.org,
	Andi Kleen <ak@linux.intel.com>
Subject: [PATCH v7 07/12] perf stat: Use affinity for closing file descriptors
Date: Fri, 15 Nov 2019 21:52:24 -0800	[thread overview]
Message-ID: <20191116055229.62002-8-andi@firstfloor.org> (raw)
In-Reply-To: <20191116055229.62002-1-andi@firstfloor.org>

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
v5:
Add comments
---
 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 dae6e846b2f8..7db49a0a0350 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)
-- 
2.23.0


  parent reply	other threads:[~2019-11-16  5:53 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-16  5:52 Optimize perf stat for large number of events/cpus Andi Kleen
2019-11-16  5:52 ` [PATCH v7 01/12] perf pmu: Use file system cache to optimize sysfs access Andi Kleen
2019-11-16  5:52 ` [PATCH v7 02/12] perf affinity: Add infrastructure to save/restore affinity Andi Kleen
2019-11-16  5:52 ` [PATCH v7 03/12] perf cpumap: Maintain cpumaps ordered and without dups Andi Kleen
2019-11-16  5:52 ` [PATCH v7 04/12] perf evlist: Maintain evlist->all_cpus Andi Kleen
2019-11-16  5:52 ` [PATCH v7 05/12] perf evsel: Add iterator to iterate over events ordered by CPU Andi Kleen
2019-11-16  5:52 ` [PATCH v7 06/12] perf evsel: Add functions to close evsel on a CPU Andi Kleen
2019-11-16  5:52 ` Andi Kleen [this message]
2019-11-16  5:52 ` [PATCH v7 08/12] perf stat: Factor out open error handling Andi Kleen
2019-11-16  5:52 ` [PATCH v7 09/12] perf stat: Use affinity for opening events Andi Kleen
2019-11-20 15:07   ` Jiri Olsa
2019-11-20 22:31     ` Andi Kleen
2019-11-21 15:13       ` Jiri Olsa
2019-11-16  5:52 ` [PATCH v7 10/12] perf stat: Use affinity for reading Andi Kleen
2019-11-20 15:12   ` Jiri Olsa
2019-11-16  5:52 ` [PATCH v7 11/12] perf evsel: Add functions to enable/disable for a specific CPU Andi Kleen
2019-11-16  5:52 ` [PATCH v7 12/12] perf stat: Use affinity for enabling/disabling events Andi Kleen
2019-11-20 15:16 ` Optimize perf stat for large number of events/cpus Jiri Olsa

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