Re: [PATCH v11 3/3]: perf record: extend trace writing to multi AIO

[Jiri Olsa <jolsa@redhat.com>]

On Mon, Oct 08, 2018 at 09:19:17AM +0300, Alexey Budankov wrote:

SNIP

>  #ifdef HAVE_AIO_SUPPORT
>  			} else {
> +				int idx;
>  				/*
>  				 * Call record__aio_sync() to wait till map->data buffer
>  				 * becomes available after previous aio write request.
>  				 */
> -				record__aio_sync(map);
> -				if (perf_mmap__aio_push(map, rec, record__aio_pushfn, &off) != 0) {
> +				idx = record__aio_sync(map, false);
> +				if (perf_mmap__aio_push(map, rec, idx, record__aio_pushfn, &off) != 0) {
>  					lseek(trace_fd, off, SEEK_SET);
>  					rc = -1;
>  					goto out;
> @@ -1446,6 +1469,10 @@ static int perf_record_config(const char *var, const char *value, void *cb)
>  		var = "call-graph.record-mode";
>  		return perf_default_config(var, value, cb);
>  	}
> +#ifdef HAVE_AIO_SUPPORT
> +	if (!strcmp(var, "record.aio-cblocks"))
> +		rec->opts.nr_cblocks = strtol(value, NULL, 0);
> +#endif
>  
>  	return 0;
>  }
> @@ -1837,6 +1864,10 @@ static struct option __record_options[] = {
>  			  "signal"),
>  	OPT_BOOLEAN(0, "dry-run", &dry_run,
>  		    "Parse options then exit"),
> +#ifdef HAVE_AIO_SUPPORT
> +	OPT_INTEGER(0, "aio-cblocks", &record.opts.nr_cblocks,
> +		    "Max number of simultaneous per-mmap trace writes (default: 0 - serial, max: 4)"),
> +#endif

could you please move the option to enable that to the previou patch?
so we could test the simple variant as well

also I think it'd be better if we have simple '--aio' option that would
enable this with some default values..  and add --aio-cblocks to configure
that further

thanks,
jirka