Re: [PATCH lttng-ust] Turn base address dump into experimental feature

Re: [PATCH lttng-ust] Turn base address dump into experimental feature

[Mathieu Desnoyers]

Merged, thanks!

Mathieu

----- Original Message -----
> From: "Paul Woegerer" <paul_woegerer@mentor.com>
> To: lttng-dev@lists.lttng.org, "mathieu desnoyers" <mathieu.desnoyers@efficios.com>
> Sent: Friday, February 28, 2014 4:02:00 AM
> Subject: [PATCH lttng-ust] Turn base address dump into experimental feature
> 
> Instead of having base address state dump enabled by default make it
> necessary to explicitly enable it with environment variable
> LTTNG_UST_WITH_EXPERIMENTAL_BADDR_STATEDUMP.
> 
> Documentation is updated to reflect this change and explain about the
> experimental nature of this feature.
> 
> Signed-off-by: Paul Woegerer <paul_woegerer@mentor.com>
> ---
>  doc/man/lttng-ust.3            | 10 +++++++---
>  liblttng-ust/lttng-ust-baddr.c |  2 +-
>  2 files changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/doc/man/lttng-ust.3 b/doc/man/lttng-ust.3
> index 2fb287a..2c58fba 100644
> --- a/doc/man/lttng-ust.3
> +++ b/doc/man/lttng-ust.3
> @@ -366,9 +366,13 @@ Pthread identifier. Can be used on architectures where
> pthread_t maps
>  nicely to an unsigned long type.
>  .PP
>  
> -.SH "BASE ADDRESS STATEDUMP"
> +.SH "BASE ADDRESS STATEDUMP (Experimental feature)"
>  
>  .PP
> +Warning: This is an experimental feature known to cause deadlocks when the
> +traced application uses fork, clone or daemon. Only use it for debugging and
> +testing.  Do NOT use it in production.
> +
>  If an application that uses liblttng-ust.so becomes part of a session,
>  information about its currently loaded shared objects will be traced to the
>  session at session-enable time. To record this information, the following
>  event
> @@ -405,8 +409,8 @@ specified in milliseconds. The value 0 means "don't
> wait". The value
>  recommended for applications with time constraints on the process
>  startup time.
>  .PP
> -.IP "LTTNG_UST_WITHOUT_BADDR_STATEDUMP"
> -Prevent liblttng-ust to perform a base-address statedump on session-enable.
> +.IP "LTTNG_UST_WITH_EXPERIMENTAL_BADDR_STATEDUMP"
> +Experimentally allow liblttng-ust to perform a base-address statedump on
> session-enable.
>  .PP
>  
>  .SH "SEE ALSO"
> diff --git a/liblttng-ust/lttng-ust-baddr.c b/liblttng-ust/lttng-ust-baddr.c
> index 922899b..dec7e82 100644
> --- a/liblttng-ust/lttng-ust-baddr.c
> +++ b/liblttng-ust/lttng-ust-baddr.c
> @@ -176,7 +176,7 @@ int lttng_ust_baddr_statedump(void *owner)
>  {
>  	struct extract_data data;
>  
> -	if (getenv("LTTNG_UST_WITHOUT_BADDR_STATEDUMP"))
> +	if (!getenv("LTTNG_UST_WITH_EXPERIMENTAL_BADDR_STATEDUMP"))
>  		return 0;
>  
>  	data.owner = owner;
> --
> 1.9.0
> 
> 

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com

[PATCH lttng-ust] Turn base address dump into experimental feature

[Paul Woegerer]

Instead of having base address state dump enabled by default make it
necessary to explicitly enable it with environment variable
LTTNG_UST_WITH_EXPERIMENTAL_BADDR_STATEDUMP.

Documentation is updated to reflect this change and explain about the
experimental nature of this feature.

Signed-off-by: Paul Woegerer <paul_woegerer@mentor.com>
---
 doc/man/lttng-ust.3            | 10 +++++++---
 liblttng-ust/lttng-ust-baddr.c |  2 +-
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/doc/man/lttng-ust.3 b/doc/man/lttng-ust.3
index 2fb287a..2c58fba 100644
--- a/doc/man/lttng-ust.3
+++ b/doc/man/lttng-ust.3
@@ -366,9 +366,13 @@ Pthread identifier. Can be used on architectures where pthread_t maps
 nicely to an unsigned long type.
 .PP
 
-.SH "BASE ADDRESS STATEDUMP"
+.SH "BASE ADDRESS STATEDUMP (Experimental feature)"
 
 .PP
+Warning: This is an experimental feature known to cause deadlocks when the
+traced application uses fork, clone or daemon. Only use it for debugging and
+testing.  Do NOT use it in production.
+
 If an application that uses liblttng-ust.so becomes part of a session,
 information about its currently loaded shared objects will be traced to the
 session at session-enable time. To record this information, the following event
@@ -405,8 +409,8 @@ specified in milliseconds. The value 0 means "don't wait". The value
 recommended for applications with time constraints on the process
 startup time.
 .PP
-.IP "LTTNG_UST_WITHOUT_BADDR_STATEDUMP"
-Prevent liblttng-ust to perform a base-address statedump on session-enable.
+.IP "LTTNG_UST_WITH_EXPERIMENTAL_BADDR_STATEDUMP"
+Experimentally allow liblttng-ust to perform a base-address statedump on session-enable.
 .PP
 
 .SH "SEE ALSO"
diff --git a/liblttng-ust/lttng-ust-baddr.c b/liblttng-ust/lttng-ust-baddr.c
index 922899b..dec7e82 100644
--- a/liblttng-ust/lttng-ust-baddr.c
+++ b/liblttng-ust/lttng-ust-baddr.c
@@ -176,7 +176,7 @@ int lttng_ust_baddr_statedump(void *owner)
 {
 	struct extract_data data;
 
-	if (getenv("LTTNG_UST_WITHOUT_BADDR_STATEDUMP"))
+	if (!getenv("LTTNG_UST_WITH_EXPERIMENTAL_BADDR_STATEDUMP"))
 		return 0;
 
 	data.owner = owner;
-- 
1.9.0