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From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Riccardo Mancini <rickyman7@gmail.com>
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
Subject: Re: [RFC PATCH v1 21/37] perf evsel: move ignore_missing_thread to fallback code
Date: Tue, 31 Aug 2021 16:44:52 -0300	[thread overview]
Message-ID: <YS6GtNjIcyA4r8O8@kernel.org> (raw)
In-Reply-To: <4eca51443c786baaf6811b7cd8e73aafd97f7606.1629490974.git.rickyman7@gmail.com>

Em Sat, Aug 21, 2021 at 11:19:27AM +0200, Riccardo Mancini escreveu:
> 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.

Thanks, looks ok, applied.

- Arnaldo

 
> 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

-- 

- Arnaldo

  reply	other threads:[~2021-08-31 19:44 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 ` [RFC PATCH v1 21/37] perf evsel: move ignore_missing_thread to fallback code Riccardo Mancini
2021-08-31 19:44   ` Arnaldo Carvalho de Melo [this message]
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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