Re: [PATCH v6 1/4] perf,record: Add clockid parameter

From: David Ahern <dsahern@gmail.com>
To: Stephane Eranian <eranian@google.com>, linux-kernel@vger.kernel.org
Cc: acme@redhat.com, peterz@infradead.org, mingo@elte.hu,
	ak@linux.intel.com, jolsa@redhat.com, namhyung@kernel.org,
	cel@us.ibm.com, sukadev@linux.vnet.ibm.com,
	sonnyrao@chromium.org, johnmccutchan@google.com,
	adrian.hunter@intel.com, pawel.moll@arm.com
Subject: Re: [PATCH v6 1/4] perf,record: Add clockid parameter
Date: Mon, 30 Mar 2015 16:24:31 -0600	[thread overview]
Message-ID: <5519CD1F.1000300@gmail.com> (raw)
In-Reply-To: <1427753974-13380-2-git-send-email-eranian@google.com>

On 3/30/15 4:19 PM, Stephane Eranian wrote:
> @@ -761,6 +762,12 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts)
>   		attr->disabled = 0;
>   		attr->enable_on_exec = 0;
>   	}
> +
> +	if (opts->clockid >= 0) {
> +		attr->use_clockid = 1;
> +		attr->clockid = opts->clockid;
> +	} else
> +		attr->clockid = -1;
>   }

The else part needs to be removed (can't set clockid to -1). And then ...

> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> index fb43215..164441a 100644
> --- a/tools/perf/util/header.c
> +++ b/tools/perf/util/header.c
> @@ -1098,6 +1098,8 @@ static void print_event_desc(struct perf_header *ph, int fd, FILE *fp)
>   			}
>   			fprintf(fp, " }");
>   		}
> +		fprintf(fp, ", clockid = %d", evsel->attr.clockid);
> +

this should be prefaced with:

     if (evsel->attr.use_clockid)

(use_clockid bit says whether the clockid value was set)