[lttng-dev] [PATCH] Fix: baddr_statedump tracepoint registration
Woegerer, Paul
Paul_Woegerer at mentor.com
Mon Dec 16 10:05:17 EST 2013
Works as expected.
Thanks,
Paul
On 12/16/2013 02:39 PM, Mathieu Desnoyers wrote:
> Hi Paul,
>
> I rewrote the patch to use a reference counting approach instead.
> The effect should be the same. Here is the commit:
>
> commit f0cc794d37abf59b4b8079612c7aa03dc305d92f
> Author: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
> Date: Mon Dec 16 08:36:06 2013 -0500
>
> Fix: baddr_statedump tracepoint registration
>
> Make sure that the ust_baddr_statedump probe is registered prior to
> using the tracepoint in lttng_ust_baddr_statedump(). This fix solves the
> issue that in rare cases the very first ust_baddr_statedump events were
> missing.
>
> Use a reference counting approach that allows constructors/destructors
> of the probe to be called many times, as long as the number of calls to
> constructor matches the number of calls to destructor.
>
> Reported-by: Paul Woegerer <paul_woegerer at mentor.com>
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
>
> Thanks,
>
> Mathieu
>
>
> ----- Original Message -----
>> From: "Paul Woegerer" <paul_woegerer at mentor.com>
>> To: "mathieu desnoyers" <mathieu.desnoyers at efficios.com>, lttng-dev at lists.lttng.org
>> Sent: Friday, December 13, 2013 8:12:02 AM
>> Subject: [PATCH] Fix: baddr_statedump tracepoint registration
>>
>> Also make sure that the ust_baddr_statedump probe get registered prior
>> to using the tracepoint in lttng_ust_baddr_statedump(). This fix solves
>> the issue that in rare cases the very first ust_baddr_statedump events
>> were missing.
>>
>> Signed-off-by: Paul Woegerer <paul_woegerer at mentor.com>
>> ---
>> include/lttng/ust-tracepoint-event.h | 10 ++++++++++
>> liblttng-ust/Makefile.am | 1 -
>> liblttng-ust/lttng-ust-baddr.c | 15 +++++++++++++++
>> liblttng-ust/ust_baddr_statedump.c | 22 ----------------------
>> 4 files changed, 25 insertions(+), 23 deletions(-)
>> delete mode 100644 liblttng-ust/ust_baddr_statedump.c
>>
>> diff --git a/include/lttng/ust-tracepoint-event.h
>> b/include/lttng/ust-tracepoint-event.h
>> index be58030..b48cd74 100644
>> --- a/include/lttng/ust-tracepoint-event.h
>> +++ b/include/lttng/ust-tracepoint-event.h
>> @@ -694,6 +694,10 @@ static struct lttng_probe_desc
>> _TP_COMBINE_TOKENS(__probe_desc___, TRACEPOINT_PR
>> * linking the probe statically.
>> */
>>
>> +#ifndef BADDR_EXPLICIT_PROBE_REGISTER
>> +#define BADDR_EXPLICIT_PROBE_REGISTER do {} while (0)
>> +#endif
>> +
>> /* Reset all macros within TRACEPOINT_EVENT */
>> #include <lttng/ust-tracepoint-event-reset.h>
>> static void lttng_ust_notrace __attribute__((constructor))
>> @@ -703,6 +707,8 @@ _TP_COMBINE_TOKENS(__lttng_events_init__,
>> TRACEPOINT_PROVIDER)(void)
>> {
>> int ret;
>>
>> + BADDR_EXPLICIT_PROBE_REGISTER;
>> +
>> /*
>> * __tracepoint_provider_check_ ## TRACEPOINT_PROVIDER() is a
>> * static inline function that ensures every probe PROVIDER
>> @@ -724,7 +730,11 @@ _TP_COMBINE_TOKENS(__lttng_events_exit__,
>> TRACEPOINT_PROVIDER)(void);
>> static void
>> _TP_COMBINE_TOKENS(__lttng_events_exit__, TRACEPOINT_PROVIDER)(void)
>> {
>> + BADDR_EXPLICIT_PROBE_REGISTER;
>> +
>> lttng_probe_unregister(&_TP_COMBINE_TOKENS(__probe_desc___,
>> TRACEPOINT_PROVIDER));
>> }
>>
>> +#undef BADDR_EXPLICIT_PROBE_REGISTER
>> +
>> int _TP_COMBINE_TOKENS(__tracepoint_provider_, TRACEPOINT_PROVIDER);
>> diff --git a/liblttng-ust/Makefile.am b/liblttng-ust/Makefile.am
>> index b165c32..e9022d8 100644
>> --- a/liblttng-ust/Makefile.am
>> +++ b/liblttng-ust/Makefile.am
>> @@ -37,7 +37,6 @@ liblttng_ust_runtime_la_SOURCES = \
>> lttng-hash-helper.h \
>> lttng-ust-baddr.c \
>> lttng-ust-baddr.h \
>> - ust_baddr_statedump.c \
>> ust_baddr_statedump.h \
>> tracepoint-internal.h \
>> clock.h \
>> diff --git a/liblttng-ust/lttng-ust-baddr.c b/liblttng-ust/lttng-ust-baddr.c
>> index b7843e2..d39e9e8 100644
>> --- a/liblttng-ust/lttng-ust-baddr.c
>> +++ b/liblttng-ust/lttng-ust-baddr.c
>> @@ -35,6 +35,15 @@
>> #include "lttng-tracer-core.h"
>> #include "lttng-ust-baddr.h"
>>
>> +#define TRACEPOINT_CREATE_PROBES
>> +#define TP_SESSION_CHECK
>> +static int explicit_probe_register;
>> +#define BADDR_EXPLICIT_PROBE_REGISTER \
>> +do { \
>> + if (!explicit_probe_register) \
>> + return; \
>> +} while (0)
>> +
>> #define TRACEPOINT_DEFINE
>> #include "ust_baddr_statedump.h"
>>
>> @@ -199,10 +208,16 @@ void lttng_ust_baddr_statedump_init(void)
>> {
>> __tracepoints__init();
>> __tracepoints__ptrs_init();
>> + explicit_probe_register = 1;
>> + __lttng_events_init__ust_baddr_statedump();
>> + explicit_probe_register = 0;
>> }
>>
>> void lttng_ust_baddr_statedump_destroy(void)
>> {
>> + explicit_probe_register = 1;
>> + __lttng_events_exit__ust_baddr_statedump();
>> + explicit_probe_register = 0;
>> __tracepoints__ptrs_destroy();
>> __tracepoints__destroy();
>> }
>> diff --git a/liblttng-ust/ust_baddr_statedump.c
>> b/liblttng-ust/ust_baddr_statedump.c
>> deleted file mode 100644
>> index 9097008..0000000
>> --- a/liblttng-ust/ust_baddr_statedump.c
>> +++ /dev/null
>> @@ -1,22 +0,0 @@
>> -/*
>> - * Copyright (C) 2013 Paul Woegerer <paul_woegerer at mentor.com>
>> - *
>> - * This library is free software; you can redistribute it and/or
>> - * modify it under the terms of the GNU Lesser General Public
>> - * License as published by the Free Software Foundation; either
>> - * version 2.1 of the License, or (at your option) any later version.
>> - *
>> - * This library is distributed in the hope that it will be useful,
>> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
>> - * Lesser General Public License for more details.
>> - *
>> - * You should have received a copy of the GNU Lesser General Public
>> - * License along with this library; if not, write to the Free Software
>> - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
>> USA
>> - */
>> -
>> -#define _LGPL_SOURCE
>> -#define TRACEPOINT_CREATE_PROBES
>> -#define TP_SESSION_CHECK
>> -#include "ust_baddr_statedump.h"
>> --
>> 1.8.5
>>
>>
--
Paul Woegerer, SW Development Engineer
Sourcery Analyzer <http://go.mentor.com/sourceryanalyzer>
Mentor Graphics, Embedded Software Division
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