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From: Riccardo Mancini <rickyman7@gmail.com>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>,
	Namhyung Kim <namhyung@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Mark Rutland <mark.rutland@arm.com>, Jiri Olsa <jolsa@redhat.com>,
	linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
	Riccardo Mancini <rickyman7@gmail.com>
Subject: [RFC PATCH v1 21/37] perf evsel: move ignore_missing_thread to fallback code
Date: Sat, 21 Aug 2021 11:19:27 +0200	[thread overview]
Message-ID: <4eca51443c786baaf6811b7cd8e73aafd97f7606.1629490974.git.rickyman7@gmail.com> (raw)
In-Reply-To: <cover.1629490974.git.rickyman7@gmail.com>

This patch moves ignore_missing_thread outside the perf_event_open loop.
Doing so, we need to move the retry_open flag a few places higher, with
minimal impact. Furthermore, thread need not be decreased since it won't
get increased by the for loop (since we're jumping back inside), but we
need to check that the nthreads decrease didn't put thread out of range.

The goal is to have fallbacks handled in one place only, since in the
future parallel code, these would be handled separately.

Signed-off-by: Riccardo Mancini <rickyman7@gmail.com>
---
 tools/perf/util/evsel.c | 29 +++++++++++++----------------
 tools/perf/util/evsel.h |  5 +++++
 2 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 916930ea31450265..a1a88607fd59efcb 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1656,7 +1656,7 @@ static int update_fds(struct evsel *evsel,
 	return 0;
 }
 
-static bool ignore_missing_thread(struct evsel *evsel,
+bool evsel__ignore_missing_thread(struct evsel *evsel,
 				  int nr_cpus, int cpu,
 				  struct perf_thread_map *threads,
 				  int thread, int err)
@@ -1993,12 +1993,15 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
 
 		for (thread = 0; thread < nthreads; thread++) {
 			int fd, group_fd;
+retry_open:
+			if (thread >= nthreads)
+				break;
 
 			if (!evsel->cgrp && !evsel->core.system_wide)
 				pid = perf_thread_map__pid(threads, thread);
 
 			group_fd = get_group_fd(evsel, cpu, thread);
-retry_open:
+
 			test_attr__ready();
 
 			fd = perf_event_open(evsel, pid, cpus->map[cpu],
@@ -2016,20 +2019,6 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
 			if (fd < 0) {
 				err = -errno;
 
-				if (ignore_missing_thread(evsel, cpus->nr, cpu, threads, thread, err)) {
-					/*
-					 * We just removed 1 thread, so take a step
-					 * back on thread index and lower the upper
-					 * nthreads limit.
-					 */
-					nthreads--;
-					thread--;
-
-					/* ... and pretend like nothing have happened. */
-					err = 0;
-					continue;
-				}
-
 				pr_debug2_peo("\nsys_perf_event_open failed, error %d\n",
 					  err);
 				goto try_fallback;
@@ -2069,6 +2058,14 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
 	return 0;
 
 try_fallback:
+	if (evsel__ignore_missing_thread(evsel, cpus->nr, cpu, threads, thread, err)) {
+		/* We just removed 1 thread, so lower the upper nthreads limit. */
+		nthreads--;
+
+		/* ... and pretend like nothing have happened. */
+		err = 0;
+		goto retry_open;
+	}
 	/*
 	 * perf stat needs between 5 and 22 fds per CPU. When we run out
 	 * of them try to increase the limits.
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index bf9abd9a5cbf9852..661d2677a19b6248 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -293,6 +293,11 @@ bool evsel__detect_missing_features(struct evsel *evsel);
 enum rlimit_action { NO_CHANGE, SET_TO_MAX, INCREASED_MAX };
 bool evsel__increase_rlimit(enum rlimit_action *set_rlimit);
 
+bool evsel__ignore_missing_thread(struct evsel *evsel,
+				  int nr_cpus, int cpu,
+				  struct perf_thread_map *threads,
+				  int thread, int err);
+
 struct perf_sample;
 
 void *evsel__rawptr(struct evsel *evsel, struct perf_sample *sample, const char *name);
-- 
2.31.1


  parent reply	other threads:[~2021-08-21  9:21 UTC|newest]

Thread overview: 63+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-21  9:19 [RFC PATCH v1 00/37] perf: use workqueue for evlist operations Riccardo Mancini
2021-08-21  9:19 ` [RFC PATCH v1 01/37] libperf cpumap: improve idx function Riccardo Mancini
2021-08-31 18:46   ` Arnaldo Carvalho de Melo
2021-10-08 14:29   ` Arnaldo Carvalho de Melo
2021-08-21  9:19 ` [RFC PATCH v1 02/37] libperf cpumap: improve max function Riccardo Mancini
2021-08-31 18:47   ` Arnaldo Carvalho de Melo
2021-08-31 19:16     ` Arnaldo Carvalho de Melo
2021-08-21  9:19 ` [RFC PATCH v1 03/37] perf evlist: replace evsel__cpu_iter* functions with evsel__find_cpu Riccardo Mancini
2021-10-08 14:38   ` [RFC PATCH v1 03/37] perf evlist: replace evsel__cpu_iter* functions with evsel__find_cpu() Arnaldo Carvalho de Melo
2021-12-11  0:20   ` [RFC PATCH v1 03/37] perf evlist: replace evsel__cpu_iter* functions with evsel__find_cpu Ian Rogers
2021-08-21  9:19 ` [RFC PATCH v1 04/37] perf util: add mmap_cpu_mask__duplicate function Riccardo Mancini
2021-08-31 19:21   ` Arnaldo Carvalho de Melo
2021-08-21  9:19 ` [RFC PATCH v1 05/37] perf util/mmap: add missing bitops.h header Riccardo Mancini
2021-08-31 19:22   ` Arnaldo Carvalho de Melo
2021-08-21  9:19 ` [RFC PATCH v1 06/37] perf workqueue: add affinities to threadpool Riccardo Mancini
2021-08-21  9:19 ` [RFC PATCH v1 07/37] perf workqueue: add support for setting affinities to workers Riccardo Mancini
2021-08-21  9:19 ` [RFC PATCH v1 08/37] perf workqueue: add method to execute work on specific CPU Riccardo Mancini
2021-08-21  9:19 ` [RFC PATCH v1 09/37] perf python: add workqueue dependency Riccardo Mancini
2021-08-21  9:19 ` [RFC PATCH v1 10/37] perf evlist: add multithreading helper Riccardo Mancini
2021-08-21  9:19 ` [RFC PATCH v1 11/37] perf evlist: add multithreading to evlist__disable Riccardo Mancini
2021-08-21  9:19 ` [RFC PATCH v1 12/37] perf evlist: add multithreading to evlist__enable Riccardo Mancini
2021-08-21  9:19 ` [RFC PATCH v1 13/37] perf evlist: add multithreading to evlist__close Riccardo Mancini
2021-08-21  9:19 ` [RFC PATCH v1 14/37] perf evsel: remove retry_sample_id goto label Riccardo Mancini
2021-08-31 19:25   ` Arnaldo Carvalho de Melo
2021-08-21  9:19 ` [RFC PATCH v1 15/37] perf evsel: separate open preparation from open itself Riccardo Mancini
2021-08-31 19:27   ` Arnaldo Carvalho de Melo
2021-08-21  9:19 ` [RFC PATCH v1 16/37] perf evsel: save open flags in evsel Riccardo Mancini
2021-08-31 19:31   ` Arnaldo Carvalho de Melo
2021-08-21  9:19 ` [RFC PATCH v1 17/37] perf evsel: separate missing feature disabling from evsel__open_cpu Riccardo Mancini
2021-08-31 19:35   ` Arnaldo Carvalho de Melo
2021-08-21  9:19 ` [RFC PATCH v1 18/37] perf evsel: add evsel__prepare_open function Riccardo Mancini
2021-08-31 19:36   ` Arnaldo Carvalho de Melo
2021-08-21  9:19 ` [RFC PATCH v1 19/37] perf evsel: separate missing feature detection from evsel__open_cpu Riccardo Mancini
2021-08-31 19:39   ` Arnaldo Carvalho de Melo
2021-08-21  9:19 ` [RFC PATCH v1 20/37] perf evsel: separate rlimit increase " Riccardo Mancini
2021-08-31 19:41   ` Arnaldo Carvalho de Melo
2021-08-21  9:19 ` Riccardo Mancini [this message]
2021-08-31 19:44   ` [RFC PATCH v1 21/37] perf evsel: move ignore_missing_thread to fallback code Arnaldo Carvalho de Melo
2021-08-21  9:19 ` [RFC PATCH v1 22/37] perf evsel: move test_attr__open to success path in evsel__open_cpu Riccardo Mancini
2021-08-31 19:47   ` Arnaldo Carvalho de Melo
2021-08-21  9:19 ` [RFC PATCH v1 23/37] perf evsel: move bpf_counter__install_pe " Riccardo Mancini
2021-08-31 19:50   ` Arnaldo Carvalho de Melo
2021-08-21  9:19 ` [RFC PATCH v1 24/37] perf evsel: handle precise_ip fallback " Riccardo Mancini
2021-08-31 19:52   ` Arnaldo Carvalho de Melo
2021-08-21  9:19 ` [RFC PATCH v1 25/37] perf evsel: move event open in evsel__open_cpu to separate function Riccardo Mancini
2021-08-31 19:54   ` Arnaldo Carvalho de Melo
2021-09-03 21:52     ` Riccardo Mancini
2021-09-11 19:10       ` Arnaldo Carvalho de Melo
2021-08-21  9:19 ` [RFC PATCH v1 26/37] perf evsel: add evsel__open_per_cpu_no_fallback function Riccardo Mancini
2021-08-21  9:19 ` [RFC PATCH v1 27/37] perf evlist: add evlist__for_each_entry_from macro Riccardo Mancini
2021-08-31 20:06   ` Arnaldo Carvalho de Melo
2021-08-21  9:19 ` [RFC PATCH v1 28/37] perf evlist: add multithreading to evlist__open Riccardo Mancini
2021-08-21  9:19 ` [RFC PATCH v1 29/37] perf evlist: add custom fallback " Riccardo Mancini
2021-08-21  9:19 ` [RFC PATCH v1 30/37] perf record: use evlist__open_custom Riccardo Mancini
2021-08-21  9:19 ` [RFC PATCH v1 31/37] tools lib/subcmd: add OPT_UINTEGER_OPTARG option type Riccardo Mancini
2021-08-31 18:44   ` Arnaldo Carvalho de Melo
2021-08-21  9:19 ` [RFC PATCH v1 32/37] perf record: add --threads option Riccardo Mancini
2021-08-21  9:19 ` [RFC PATCH v1 33/37] perf record: pin threads to monitored cpus if enough threads available Riccardo Mancini
2021-08-21  9:19 ` [RFC PATCH v1 34/37] perf record: apply multithreading in init and fini phases Riccardo Mancini
2021-08-21  9:19 ` [RFC PATCH v1 35/37] perf test/evlist-open-close: add multithreading Riccardo Mancini
2021-08-21  9:19 ` [RFC PATCH v1 36/37] perf test/evlist-open-close: use inline func to convert timeval to usec Riccardo Mancini
2021-10-08 14:46   ` Arnaldo Carvalho de Melo
2021-08-21  9:19 ` [RFC PATCH v1 37/37] perf test/evlist-open-close: add detailed output mode Riccardo Mancini

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