From: Tom Zanussi <tom.zanussi@linux.intel.com>
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: rostedt <rostedt@goodmis.org>,
Thomas Gleixner <tglx@linutronix.de>,
Masami Hiramatsu <mhiramat@kernel.org>,
Namhyung Kim <namhyung@kernel.org>,
vedang patel <vedang.patel@intel.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
joel opensrc <joel.opensrc@gmail.com>,
Joel Fernandes <joelaf@google.com>,
baohong liu <baohong.liu@intel.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
linux-rt-users@vger.kernel.org
Subject: Re: [PATCH v2 25/40] tracing: Add support for dynamic tracepoints
Date: Tue, 05 Sep 2017 21:35:12 -0500 [thread overview]
Message-ID: <1504665312.8876.1.camel@tzanussi-mobl.amr.corp.intel.com> (raw)
In-Reply-To: <839654631.3898.1504654171688.JavaMail.zimbra@efficios.com>
Hi Mathieu,
On Tue, 2017-09-05 at 23:29 +0000, Mathieu Desnoyers wrote:
> ----- On Sep 5, 2017, at 5:57 PM, Tom Zanussi tom.zanussi@linux.intel.com wrote:
>
> > The tracepoint infrastructure assumes statically-defined tracepoints
> > and uses static_keys for tracepoint enablement. In order to define
> > tracepoints on the fly, we need to have a dynamic counterpart.
> >
> > Add a 'dynamic' flag to struct tracepoint along with accompanying
> > logic for this purpose.
> >
> > Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
> > ---
> > include/linux/tracepoint-defs.h | 1 +
> > kernel/tracepoint.c | 18 +++++++++++++-----
> > 2 files changed, 14 insertions(+), 5 deletions(-)
> >
> > diff --git a/include/linux/tracepoint-defs.h b/include/linux/tracepoint-defs.h
> > index a031920..bc22d54 100644
> > --- a/include/linux/tracepoint-defs.h
> > +++ b/include/linux/tracepoint-defs.h
> > @@ -32,6 +32,7 @@ struct tracepoint {
> > int (*regfunc)(void);
> > void (*unregfunc)(void);
> > struct tracepoint_func __rcu *funcs;
> > + bool dynamic;
> > };
> >
> > #endif
> > diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
> > index 685c50a..1c5957f 100644
> > --- a/kernel/tracepoint.c
> > +++ b/kernel/tracepoint.c
> > @@ -197,7 +197,9 @@ static int tracepoint_add_func(struct tracepoint *tp,
> > struct tracepoint_func *old, *tp_funcs;
> > int ret;
> >
> > - if (tp->regfunc && !static_key_enabled(&tp->key)) {
> > + if (tp->regfunc &&
> > + ((tp->dynamic && !(atomic_read(&tp->key.enabled) > 0)) ||
> > + !static_key_enabled(&tp->key))) {
> > ret = tp->regfunc();
> > if (ret < 0)
> > return ret;
> > @@ -219,7 +221,9 @@ static int tracepoint_add_func(struct tracepoint *tp,
> > * is used.
> > */
> > rcu_assign_pointer(tp->funcs, tp_funcs);
> > - if (!static_key_enabled(&tp->key))
> > + if (tp->dynamic && !(atomic_read(&tp->key.enabled) > 0))
> > + atomic_inc(&tp->key.enabled);
> > + else if (!tp->dynamic && !static_key_enabled(&tp->key))
> > static_key_slow_inc(&tp->key);
> > release_probes(old);
> > return 0;
> > @@ -246,10 +250,14 @@ static int tracepoint_remove_func(struct tracepoint *tp,
> >
> > if (!tp_funcs) {
> > /* Removed last function */
> > - if (tp->unregfunc && static_key_enabled(&tp->key))
> > + if (tp->unregfunc &&
> > + ((tp->dynamic && (atomic_read(&tp->key.enabled) > 0)) ||
> > + static_key_enabled(&tp->key)))
> > tp->unregfunc();
> >
> > - if (static_key_enabled(&tp->key))
> > + if (tp->dynamic && (atomic_read(&tp->key.enabled) > 0))
> > + atomic_dec(&tp->key.enabled);
> > + else if (!tp->dynamic && static_key_enabled(&tp->key))
> > static_key_slow_dec(&tp->key);
> > }
> > rcu_assign_pointer(tp->funcs, tp_funcs);
> > @@ -258,7 +266,7 @@ static int tracepoint_remove_func(struct tracepoint *tp,
> > }
> >
> > /**
> > - * tracepoint_probe_register - Connect a probe to a tracepoint
> > + * tracepoint_probe_register_prio - Connect a probe to a tracepoint
> > * @tp: tracepoint
> > * @probe: probe handler
> > * @data: tracepoint data
>
> Hi Tom,
>
> Thanks for updating your approach to dynamic tracepoints.
>
> Since you're fixing up this comment above tracepoint_probe_register_prio,
> can you also remove the following line above tracepoint_probe_register
> while you are at it ?
>
Sure, will do.
Thanks,
Tom
next prev parent reply other threads:[~2017-09-06 2:35 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 [this message]
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
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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