Re: [PATCH v3 01/12] perf record: introduce thread affinity and mmap masks

From: Namhyung Kim <namhyung@kernel.org>
To: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
	Jiri Olsa <jolsa@redhat.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Andi Kleen <ak@linux.intel.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>,
	Alexander Antonov <alexander.antonov@linux.intel.com>
Subject: Re: [PATCH v3 01/12] perf record: introduce thread affinity and mmap masks
Date: Fri, 20 Nov 2020 19:01:25 +0900	[thread overview]
Message-ID: <20201120100125.GB94830@google.com> (raw)
In-Reply-To: <e92d3f86-baa5-0e62-50bd-151f33969baa@linux.intel.com>

On Mon, Nov 16, 2020 at 03:14:50PM +0300, Alexey Budankov wrote:
> 
> Introduce affinity and mmap thread masks. Thread affinity mask
> defines cpus that a thread is allowed to run on. Thread maps
> mask defines mmap data buffers the thread serves to stream
> profiling data from.
> 
> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
> ---
>  tools/perf/builtin-record.c | 116 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 116 insertions(+)
> 
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index adf311d15d3d..82f009703ad7 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
[SNIP]
> +static int record__alloc_thread_masks(struct record *rec, int nr_threads, int nr_bits)
> +{
> +	int t, ret;
> +
> +	rec->thread_masks = zalloc(nr_threads * sizeof(*(rec->thread_masks)));
> +	if (!rec->thread_masks) {
> +		pr_err("Failed to allocate thread masks\n");
> +		return -ENOMEM;
> +	}
> +
> +	for (t = 0; t < nr_threads; t++) {
> +		ret = record__thread_mask_alloc(&rec->thread_masks[t], nr_bits);
> +		if (ret)
> +			return ret;
> +		record__thread_mask_clear(&rec->thread_masks[t]);
> +	}
> +
> +	return 0;
> +}
> +static int record__init_thread_default_masks(struct record *rec, struct perf_cpu_map *cpus)
> +{
> +	int ret;
> +
> +	ret = record__alloc_thread_masks(rec, 1, cpu__max_cpu());
> +	if (ret)
> +		return ret;
> +
> +	record__mmap_cpu_mask_init(&rec->thread_masks->maps, cpus);
> +
> +	rec->nr_threads = 1;
> +
> +	return 0;
> +}
> +
> +static int record__init_thread_masks(struct record *rec)
> +{
> +	struct perf_cpu_map *cpus = rec->evlist->core.cpus;
> +
> +	return record__init_thread_default_masks(rec, cpus);
> +}
> +
> +static int record__fini_thread_masks(struct record *rec)
> +{
> +	int t;
> +
> +	for (t = 0; t < rec->nr_threads; t++)
> +		record__thread_mask_free(&rec->thread_masks[t]);

It might be failed when allocating rec->thread_masks.

Thanks
Namhyung

> +
> +	zfree(&rec->thread_masks);
> +
> +	rec->nr_threads = 0;
> +
> +	return 0;
> +}
> +
>  int cmd_record(int argc, const char **argv)
>  {
>  	int err;
> @@ -2821,6 +2930,12 @@ int cmd_record(int argc, const char **argv)
>  		goto out;
>  	}
>  
> +	err = record__init_thread_masks(rec);
> +	if (err) {
> +		pr_err("record__init_thread_masks failed, error %d\n", err);
> +		goto out;
> +	}
> +
>  	if (rec->opts.nr_cblocks > nr_cblocks_max)
>  		rec->opts.nr_cblocks = nr_cblocks_max;
>  	pr_debug("nr_cblocks: %d\n", rec->opts.nr_cblocks);
> @@ -2839,6 +2954,7 @@ int cmd_record(int argc, const char **argv)
>  	symbol__exit();
>  	auxtrace_record__free(rec->itr);
>  out_opts:
> +	record__fini_thread_masks(rec);
>  	evlist__close_control(rec->opts.ctl_fd, rec->opts.ctl_fd_ack, &rec->opts.ctl_fd_close);
>  	return err;
>  }
> -- 
> 2.24.1
> 