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Message-ID: <CABPqkBR_ou8E01kRmDOBb72ngcdzBkfVPNUj71XWnsYE6i0Bdg@mail.gmail.com>
Date: Fri, 27 Mar 2015 15:37:47 -0700
From: Stephane Eranian <eranian@...gle.com>
To: Peter Zijlstra <peterz@...radead.org>
Cc: Arnaldo Carvalho de Melo <acme@...hat.com>,
David Ahern <dsahern@...il.com>,
Thomas Gleixner <tglx@...utronix.de>,
Jiri Olsa <jolsa@...hat.com>,
Linus Torvalds <torvalds@...ux-foundation.org>,
LKML <linux-kernel@...r.kernel.org>,
John Stultz <john.stultz@...aro.org>,
"H. Peter Anvin" <hpa@...or.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Ingo Molnar <mingo@...nel.org>
Subject: Re: [PATCH] perf, record: Add clockid parameter
On Fri, Mar 27, 2015 at 2:59 PM, Peter Zijlstra <peterz@...radead.org> wrote:
> On Fri, Mar 27, 2015 at 05:15:34PM -0300, Arnaldo Carvalho de Melo wrote:
>> I.e. we're back to the sys_perf_event_open() error reporting suckz rockz
>> thing, this time with PeterZ trying to find a way to avoid getting back
>> to that discussion... /me runz... ;-P
>
> :-)
>
> Not entirely, its just that I've not seen this userspace code in years
> and I'm pretty clueless.
>
> How about so then?
>
> ---
> Subject: perf, record: Add clockid parameter
> From: Peter Zijlstra <peterz@...radead.org>
> Date: Fri, 27 Mar 2015 15:32:01 +0100
>
> Teach perf-record about the new perf_event_attr::{use_clockid, clockid}
> fields. Add a simple parameter to set the clock (if any) to be used for
> the events to be recorded into the data file.
>
> Since we store the entire perf_event_attr in the EVENT_DESC section we
> also already store the used clockid in the data file.
>
> Cc: acme@...hat.com
> Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
> ---
>
> tools/perf/Documentation/perf-record.txt | 5 +++
> tools/perf/builtin-record.c | 3 ++
> tools/perf/perf.h | 1
> tools/perf/util/evsel.c | 44 ++++++++++++++++++++++++++++---
> 4 files changed, 49 insertions(+), 4 deletions(-)
>
> --- a/tools/perf/Documentation/perf-record.txt
> +++ b/tools/perf/Documentation/perf-record.txt
> @@ -250,6 +250,11 @@ is off by default.
> --running-time::
> Record running and enabled time for read events (:S)
>
> +-k::
> +--clockid::
> +Sets the clock id to use for the various time fields in the perf_event_type
> +records. See clock_gettime().
> +
> SEE ALSO
> --------
> linkperf:perf-stat[1], linkperf:perf-list[1]
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -739,6 +739,7 @@ static struct record record = {
> .uses_mmap = true,
> .default_per_cpu = true,
> },
> + .clockid = -1,
> },
> .tool = {
> .sample = process_sample_event,
> @@ -842,6 +843,8 @@ struct option __record_options[] = {
> "Sample machine registers on interrupt"),
> OPT_BOOLEAN(0, "running-time", &record.opts.running_time,
> "Record running/enabled time of read (:S) events"),
> + OPT_INTEGER('k', "clockid", &record.opts.clockid,
> + "clockid to use for events"),
I think you'd want a symbolic name for the clock to make this easier
on the user.
> OPT_END()
> };
>
> --- a/tools/perf/perf.h
> +++ b/tools/perf/perf.h
> @@ -62,6 +62,7 @@ struct record_opts {
> u64 user_interval;
> bool sample_transaction;
> unsigned initial_delay;
> + clockid_t clockid;
> };
>
> struct option;
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -32,6 +32,7 @@ static struct {
> bool exclude_guest;
> bool mmap2;
> bool cloexec;
> + bool clockid;
> } perf_missing_features;
>
> static int perf_evsel__no_extra_init(struct perf_evsel *evsel __maybe_unused)
> @@ -761,6 +762,11 @@ void perf_evsel__config(struct perf_evse
> attr->disabled = 0;
> attr->enable_on_exec = 0;
> }
> +
> + if (opts->clockid >= 0) {
> + attr->use_clockid = 1;
> + attr->clockid = opts->clockid;
> + }
> }
>
> static int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
> @@ -1036,7 +1042,6 @@ static size_t perf_event_attr__fprintf(s
> ret += PRINT_ATTR2(exclude_user, exclude_kernel);
> ret += PRINT_ATTR2(exclude_hv, exclude_idle);
> ret += PRINT_ATTR2(mmap, comm);
> - ret += PRINT_ATTR2(mmap2, comm_exec);
> ret += PRINT_ATTR2(freq, inherit_stat);
> ret += PRINT_ATTR2(enable_on_exec, task);
> ret += PRINT_ATTR2(watermark, precise_ip);
> @@ -1044,6 +1049,8 @@ static size_t perf_event_attr__fprintf(s
> ret += PRINT_ATTR2(exclude_host, exclude_guest);
> ret += PRINT_ATTR2N("excl.callchain_kern", exclude_callchain_kernel,
> "excl.callchain_user", exclude_callchain_user);
> + ret += PRINT_ATTR2(mmap2, comm_exec);
> + ret += __PRINT_ATTR("%u",,use_clockid);
>
> ret += PRINT_ATTR_U32(wakeup_events);
> ret += PRINT_ATTR_U32(wakeup_watermark);
> @@ -1055,6 +1062,7 @@ static size_t perf_event_attr__fprintf(s
> ret += PRINT_ATTR_X64(branch_sample_type);
> ret += PRINT_ATTR_X64(sample_regs_user);
> ret += PRINT_ATTR_U32(sample_stack_user);
> + ret += PRINT_ATTR_U32(clockid);
> ret += PRINT_ATTR_X64(sample_regs_intr);
>
> ret += fprintf(fp, "%.60s\n", graph_dotted_line);
> @@ -1085,6 +1093,8 @@ static int __perf_evsel__open(struct per
> }
>
> fallback_missing_features:
> + if (perf_missing_features.clockid)
> + evsel->attr.use_clockid = 0;
> if (perf_missing_features.cloexec)
> flags &= ~(unsigned long)PERF_FLAG_FD_CLOEXEC;
> if (perf_missing_features.mmap2)
> @@ -1122,6 +1132,16 @@ static int __perf_evsel__open(struct per
> goto try_fallback;
> }
> set_rlimit = NO_CHANGE;
> +
> + /*
> + * If we succeeded but had to kill clockid, fail and
> + * have perf_evsel__open_strerror() print us a nice
> + * error.
> + */
> + if (perf_missing_features.clockid) {
> + err = -EINVAL;
> + goto out_close;
> + }
> }
> }
>
> @@ -1155,7 +1175,10 @@ static int __perf_evsel__open(struct per
> if (err != -EINVAL || cpu > 0 || thread > 0)
> goto out_close;
>
> - if (!perf_missing_features.cloexec && (flags & PERF_FLAG_FD_CLOEXEC)) {
> + if (!perf_missing_features.clockid && evsel->attr.use_clockid) {
> + perf_missing_features.clockid = true;
> + goto fallback_missing_features;
> + } else if (!perf_missing_features.cloexec && (flags & PERF_FLAG_FD_CLOEXEC)) {
> perf_missing_features.cloexec = true;
> goto fallback_missing_features;
> } else if (!perf_missing_features.mmap2 && evsel->attr.mmap2) {
> @@ -2063,9 +2086,7 @@ int perf_evsel__fprintf(struct perf_evse
> if_print(exclude_hv);
> if_print(exclude_idle);
> if_print(mmap);
> - if_print(mmap2);
> if_print(comm);
> - if_print(comm_exec);
> if_print(freq);
> if_print(inherit_stat);
> if_print(enable_on_exec);
> @@ -2076,10 +2097,19 @@ int perf_evsel__fprintf(struct perf_evse
> if_print(sample_id_all);
> if_print(exclude_host);
> if_print(exclude_guest);
> + if_print(exclude_callchain_kernel);
> + if_print(exclude_callchain_user);
> + if_print(mmap2);
> + if_print(comm_exec);
> + if_print(use_clockid);
> if_print(__reserved_1);
> if_print(wakeup_events);
> if_print(bp_type);
> if_print(branch_sample_type);
> + if_print(sample_regs_user);
> + if_print(sample_stack_user);
> + if_print(clockid);
> + if_print(sample_regs_intr);
> }
> out:
> fputc('\n', fp);
> @@ -2158,6 +2188,12 @@ int perf_evsel__open_strerror(struct per
> "The PMU counters are busy/taken by another profiler.\n"
> "We found oprofile daemon running, please stop it and try again.");
> break;
> +
> + case EINVAL:
> + if (perf_missing_features.clockid)
> + return scnprintf(msg, size, "%s", "clockid not supported.");
> + break;
> +
> default:
> break;
> }
--
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