From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jiri Olsa <jolsa@redhat.com>
Subject: Re: [PATCH v1 2/2]: perf record: enable asynchronous trace writing
Date: Sun, 26 Aug 2018 23:48:56 +0200
Message-ID: <20180826214856.GA24518@krava>
References: <dcd3ee88-57d6-8704-f5e1-7a3c75a17d8d@linux.intel.com>
 <2db359cc-dc5d-c00e-a42a-12a2e9da80b7@linux.intel.com>
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To: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@kernel.org>, Arnaldo Carvalho de Melo <acme@kernel.org>, Alexander Shishkin <alexander.shishkin@linux.intel.com>, Namhyung Kim <namhyung@kernel.org>, Andi Kleen <ak@linux.intel.com>, linux-kernel <linux-kernel@vger.kernel.org>, linux-perf-users@vger.kernel.org
List-Id: linux-perf-users.vger.kernel.org

On Tue, Aug 21, 2018 at 11:27:03AM +0300, Alexey Budankov wrote:

SNIP

> -static int record__pushfn(void *to, void *bf, size_t size)
> +static int record__pushfn(void *to, void *bf, size_t size, off_t off)
>  {
>  	struct record *rec = to;
> +	struct perf_mmap *map = bf;
>  
>  	rec->samples++;
> -	return record__write(rec, bf, size);
> +	return record__aio_write(rec->session->data->file.fd, &map->cblock,
> +			map->data, size, off);
>  }
>  
>  static volatile int done;
> @@ -528,13 +530,85 @@ static struct perf_event_header finished_round_event = {
>  	.type = PERF_RECORD_FINISHED_ROUND,
>  };
>  
> +static int record__mmap_read_sync(int trace_fd, struct aiocb **cblocks,
> +		int cblocks_size, struct record *rec)
> +{
> +	size_t rem;
> +	ssize_t size;
> +	off_t rem_off;
> +	int i, aio_ret, aio_errno, do_suspend;
> +	struct perf_mmap *md;
> +	struct timespec timeout0 = { 0, 0 };
> +	struct timespec timeoutS = { 0, 1000 * 500  * 1 };
> +
> +	if (!cblocks_size)
> +		return 0;
> +
> +	do {
> +		do_suspend = 0;
> +		nanosleep(&timeoutS, NULL);

why the extra sleep in here and not sleeping through aio_suspend call?

jirka

> +		if (aio_suspend((const struct aiocb**)cblocks, cblocks_size, &timeout0)) {
> +			if (errno == EAGAIN || errno == EINTR) {
> +				do_suspend = 1;
> +				continue;
> +			} else {
> +				pr_err("failed to sync perf data, error: %m\n");

SNIP