From: Tom Zanussi <tom.zanussi@linux.intel.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: tglx@linutronix.de, mhiramat@kernel.org, namhyung@kernel.org,
vedang.patel@intel.com, bigeasy@linutronix.de,
joel.opensrc@gmail.com, joelaf@google.com,
mathieu.desnoyers@efficios.com, baohong.liu@intel.com,
linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org
Subject: Re: [PATCH v2 32/40] tracing: Add cpu field for hist triggers
Date: Fri, 08 Sep 2017 14:35:27 -0500 [thread overview]
Message-ID: <1504899327.5276.8.camel@tzanussi-mobl.amr.corp.intel.com> (raw)
In-Reply-To: <20170908150808.6fb4295b@gandalf.local.home>
On Fri, 2017-09-08 at 15:08 -0400, Steven Rostedt wrote:
> On Tue, 5 Sep 2017 16:57:44 -0500
> Tom Zanussi <tom.zanussi@linux.intel.com> wrote:
>
> > A common key to use in a histogram is the cpuid - add a new cpu
> > 'synthetic' field for that purpose. This field is named cpu rather
> > than $cpu or $common_cpu because 'cpu' already exists as a special
> > filter field and it makes more sense to match that rather than add
> > another name for the same thing.
> >
> > Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
> > ---
> > Documentation/trace/events.txt | 18 ++++++++++++++++++
> > kernel/trace/trace_events_hist.c | 30 +++++++++++++++++++++++++++---
> > 2 files changed, 45 insertions(+), 3 deletions(-)
> >
> > diff --git a/Documentation/trace/events.txt b/Documentation/trace/events.txt
> > index 2cc08d4..9717688 100644
> > --- a/Documentation/trace/events.txt
> > +++ b/Documentation/trace/events.txt
> > @@ -668,6 +668,24 @@ The following commands are supported:
> > The examples below provide a more concrete illustration of the
> > concepts and typical usage patterns discussed above.
> >
> > + 'synthetic' event fields
> > + ------------------------
> > +
> > + There are a number of 'synthetic fields' available for use as keys
> > + or values in a hist trigger. These look like and behave as if they
> > + were event fields, but aren't actually part of the event's field
> > + definition or format file. They are however available for any
> > + event, and can be used anywhere an actual event field could be.
> > + 'Synthetic' field names are always prefixed with a '$' character to
> > + indicate that they're not normal fields (with the exception of
> > + 'cpu', for compatibility with existing filter usage):
> > +
> > + $common_timestamp u64 - timestamp (from ring buffer) associated
> > + with the event, in nanoseconds. May be
> > + modified by .usecs to have timestamps
> > + interpreted as microseconds.
>
> I guess the above should have been added with the synthetic field
> addition.
>
Yeah, somehow this bit got shuffled to the wrong place refactoring the
patches.
> > + cpu int - the cpu on which the event occurred.
>
> Then this (and the explanation of '$' for cpu above) should be added
> with this patch.
>
Yep, will do.
>
> > +
> >
> > 6.2 'hist' trigger examples
> > ---------------------------
> > diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
> > index 4f66f2e..0782766 100644
> > --- a/kernel/trace/trace_events_hist.c
> > +++ b/kernel/trace/trace_events_hist.c
> > @@ -226,6 +226,7 @@ enum hist_field_flags {
> > HIST_FIELD_FL_VAR_ONLY = 8192,
> > HIST_FIELD_FL_EXPR = 16384,
> > HIST_FIELD_FL_VAR_REF = 32768,
> > + HIST_FIELD_FL_CPU = 65536,
> > };
> >
> > struct var_defs {
> > @@ -1170,6 +1171,16 @@ static u64 hist_field_timestamp(struct hist_field *hist_field,
> > return ts;
> > }
> >
> > +static u64 hist_field_cpu(struct hist_field *hist_field,
> > + struct tracing_map_elt *elt,
> > + struct ring_buffer_event *rbe,
> > + void *event)
> > +{
> > + int cpu = raw_smp_processor_id();
>
> Hmm, I wonder if this should be just smp_processor_id(). Why have the
> raw_?
>
You're right, smp_processor_id() should be fine.
> > +
> > + return cpu;
> > +}
> > +
> > static struct hist_field *check_var_ref(struct hist_field *hist_field,
> > struct hist_trigger_data *var_data,
> > unsigned int var_idx)
> > @@ -1518,6 +1529,8 @@ static const char *hist_field_name(struct hist_field *field,
> > field_name = hist_field_name(field->operands[0], ++level);
> > else if (field->flags & HIST_FIELD_FL_TIMESTAMP)
> > field_name = "$common_timestamp";
> > + else if (field->flags & HIST_FIELD_FL_CPU)
> > + field_name = "cpu";
> > else if (field->flags & HIST_FIELD_FL_EXPR ||
> > field->flags & HIST_FIELD_FL_VAR_REF)
> > field_name = field->name;
> > @@ -1990,6 +2003,15 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
> > goto out;
> > }
> >
> > + if (flags & HIST_FIELD_FL_CPU) {
> > + hist_field->fn = hist_field_cpu;
> > + hist_field->size = sizeof(int);
> > + hist_field->type = kstrdup("int", GFP_KERNEL);
> > + if (!hist_field->type)
> > + goto free;
> > + goto out;
> > + }
> > +
> > if (WARN_ON_ONCE(!field))
> > goto out;
> >
> > @@ -2182,7 +2204,9 @@ static struct hist_field *parse_var_ref(struct trace_array *tr,
> > hist_data->enable_timestamps = true;
> > if (*flags & HIST_FIELD_FL_TIMESTAMP_USECS)
> > hist_data->attrs->ts_in_usecs = true;
> > - } else {
> > + } else if (strcmp(field_name, "cpu") == 0)
> > + *flags |= HIST_FIELD_FL_CPU;
> > + else {
> > field = trace_find_event_field(file->event_call, field_name);
> > if (!field || !field->size) {
> > field = ERR_PTR(-EINVAL);
>
>
> > @@ -3185,7 +3209,6 @@ static int onmatch_create(struct hist_trigger_data *hist_data,
> > goto out;
> > }
> > }
> > -
> > if (param[0] == '$')
> > hist_field = onmatch_find_var(hist_data, data, system,
> > event_name, param);
> > @@ -3200,7 +3223,6 @@ static int onmatch_create(struct hist_trigger_data *hist_data,
> > ret = -EINVAL;
> > goto out;
> > }
> > -
>
> Why the modification of whitespace here?
>
Again no good reason, another casualty of refactoring lots of
patches ;-)
Tom
next prev parent reply other threads:[~2017-09-08 19:35 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-05 21:57 [PATCH v2 00/40] tracing: Inter-event (e.g. latency) support Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 01/40] tracing: Exclude 'generic fields' from histograms Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 02/40] tracing: Add support to detect and avoid duplicates Tom Zanussi
2017-09-06 18:32 ` Steven Rostedt
2017-09-06 18:47 ` Steven Rostedt
2017-09-06 20:58 ` Patel, Vedang
2017-09-05 21:57 ` [PATCH v2 03/40] tracing: Remove code which merges duplicates Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 04/40] tracing: Add hist_field_name() accessor Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 05/40] tracing: Reimplement log2 Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 06/40] ring-buffer: Add interface for setting absolute time stamps Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 07/40] tracing: Apply absolute timestamps to instance max buffer Tom Zanussi
2017-09-06 19:57 ` Steven Rostedt
2017-09-07 0:49 ` Steven Rostedt
2017-09-07 1:15 ` Liu, Baohong
2017-09-05 21:57 ` [PATCH v2 08/40] ring-buffer: Redefine the unimplemented RINGBUF_TIME_TIME_STAMP Tom Zanussi
2017-09-07 14:35 ` Steven Rostedt
2017-09-07 15:05 ` Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 09/40] tracing: Give event triggers access to ring_buffer_event Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 10/40] tracing: Add ring buffer event param to hist field functions Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 11/40] tracing: Increase tracing map KEYS_MAX size Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 12/40] tracing: Break out hist trigger assignment parsing Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 13/40] tracing: Make traceprobe parsing code reusable Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 14/40] tracing: Add hist trigger timestamp support Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 15/40] tracing: Add per-element variable support to tracing_map Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 16/40] tracing: Add hist_data member to hist_field Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 17/40] tracing: Add usecs modifier for hist trigger timestamps Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 18/40] tracing: Add variable support to hist triggers Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 19/40] tracing: Account for variables in named trigger compatibility Tom Zanussi
2017-09-07 16:40 ` Steven Rostedt
2017-09-07 17:00 ` Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 20/40] tracing: Add simple expression support to hist triggers Tom Zanussi
2017-09-07 16:46 ` Steven Rostedt
2017-09-07 17:01 ` Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 21/40] tracing: Generalize per-element hist trigger data Tom Zanussi
2017-09-07 17:56 ` Steven Rostedt
2017-09-07 18:14 ` Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 22/40] tracing: Pass tracing_map_elt to hist_field accessor functions Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 23/40] tracing: Add hist_field 'type' field Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 24/40] tracing: Add variable reference handling to hist triggers Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 25/40] tracing: Add support for dynamic tracepoints Tom Zanussi
2017-09-05 23:29 ` Mathieu Desnoyers
2017-09-06 2:35 ` Tom Zanussi
2017-09-07 22:02 ` Steven Rostedt
2017-09-08 14:18 ` Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 26/40] tracing: Add hist trigger action hook Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 27/40] tracing: Add support for 'synthetic' events Tom Zanussi
2017-09-07 23:40 ` Steven Rostedt
2017-09-08 14:30 ` Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 28/40] tracing: Add support for 'field variables' Tom Zanussi
2017-09-07 23:43 ` Steven Rostedt
2017-09-08 15:37 ` Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 29/40] tracing: Add 'onmatch' hist trigger action support Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 30/40] tracing: Add 'onmax' " Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 31/40] tracing: Allow whitespace to surround hist trigger filter Tom Zanussi
2017-09-08 18:50 ` Steven Rostedt
2017-09-08 19:08 ` Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 32/40] tracing: Add cpu field for hist triggers Tom Zanussi
2017-09-08 19:08 ` Steven Rostedt
2017-09-08 19:35 ` Tom Zanussi [this message]
2017-09-05 21:57 ` [PATCH v2 33/40] tracing: Add hist trigger support for variable reference aliases Tom Zanussi
2017-09-08 19:09 ` Steven Rostedt
2017-09-08 19:41 ` Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 34/40] tracing: Add 'last error' error facility for hist triggers Tom Zanussi
2017-09-08 19:25 ` Steven Rostedt
2017-09-08 19:44 ` Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 35/40] tracing: Reverse the order event_mutex/trace_types_lock are taken Tom Zanussi
2017-09-08 19:31 ` Steven Rostedt
2017-09-08 19:41 ` Steven Rostedt
2017-09-08 20:00 ` Steven Rostedt
2017-09-05 21:57 ` [PATCH v2 36/40] tracing: Remove lookups from tracing_map hitcount Tom Zanussi
2017-09-12 2:16 ` Masami Hiramatsu
2017-09-12 14:16 ` Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 37/40] tracing: Add inter-event hist trigger Documentation Tom Zanussi
2017-09-20 14:44 ` Julia Cartwright
2017-09-20 17:15 ` Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 38/40] tracing: Make tracing_set_clock() non-static Tom Zanussi
2017-09-12 2:18 ` Masami Hiramatsu
2017-09-12 14:18 ` Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 39/40] tracing: Add a clock attribute for hist triggers Tom Zanussi
2017-09-05 21:57 ` [PATCH v2 40/40] tracing: Add trace_event_buffer_reserve() variant that allows recursion Tom Zanussi
2017-09-07 22:29 ` kbuild test robot
2017-09-07 22:35 ` kbuild test robot
2017-09-08 20:27 ` Steven Rostedt
2017-09-08 20:41 ` Tom Zanussi
2017-09-12 1:50 ` [PATCH v2 00/40] tracing: Inter-event (e.g. latency) support Masami Hiramatsu
2017-09-12 14:14 ` Tom Zanussi
2017-09-19 16:31 ` Steven Rostedt
2017-09-19 18:44 ` Tom Zanussi
2017-09-21 20:20 ` Steven Rostedt
2017-09-21 21:11 ` Tom Zanussi
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