[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <87vbwu1h8d.fsf@sejong.aot.lge.com>
Date: Wed, 05 Feb 2014 10:27:30 +0900
From: Namhyung Kim <namhyung@...nel.org>
To: Jiri Olsa <jolsa@...hat.com>
Cc: linux-kernel@...r.kernel.org,
Corey Ashford <cjashfor@...ux.vnet.ibm.com>,
David Ahern <dsahern@...il.com>, Ingo Molnar <mingo@...e.hu>,
Paul Mackerras <paulus@...ba.org>,
Peter Zijlstra <a.p.zijlstra@...llo.nl>,
Arnaldo Carvalho de Melo <acme@...hat.com>,
Andi Kleen <andi@...stfloor.org>,
Adrian Hunter <adrian.hunter@...el.com>
Subject: Re: [PATCH 1/3] perf tools: Put proper period for for samples without PERIOD sample_type
Hi Jiri,
On Mon, 3 Feb 2014 12:44:41 +0100, Jiri Olsa wrote:
> We use PERF_SAMPLE_PERIOD sample type only for frequency
> setup -F (default) option. The -c does not need store period,
> because it's always the same.
>
> In -c case the report code uses '1' as period. Fixing
> it to perf_event_attr::sample_period.
All 3 patches look good. But I found something strange. When we
setup/config evsel attrs following code is used:
util/evsel.c::perf_evsel__config()
/*
* We default some events to a 1 default interval. But keep
* it a weak assumption overridable by the user.
*/
if (!attr->sample_period || (opts->user_freq != UINT_MAX &&
opts->user_interval != ULLONG_MAX)) {
if (opts->freq) {
perf_evsel__set_sample_bit(evsel, PERIOD);
attr->freq = 1;
attr->sample_freq = opts->freq;
} else {
attr->sample_period = opts->default_interval;
}
}
But shouldn't it be "||" instead of "&&" for checking
user_freq/interval? The opts->freq was setup by code below
util/record.c::record_opts__config_freq()
bool user_freq = opts->user_freq != UINT_MAX;
unsigned int max_rate;
if (opts->user_interval != ULLONG_MAX)
opts->default_interval = opts->user_interval;
if (user_freq)
opts->freq = opts->user_freq;
/*
* User specified count overrides default frequency.
*/
if (opts->default_interval)
opts->freq = 0;
else if (opts->freq) {
opts->default_interval = opts->freq;
} else {
pr_err("frequency and count are zero, aborting\n");
return -1;
}
Thanks,
Namhyung
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists