Linux-Trace-Users Archive on lore.kernel.org
 help / color / Atom feed
From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: lttng-dev@lists.lttng.org,
	diamon-discuss@lists.linuxfoundation.org,
	linux-trace-users@vger.kernel.org
Subject: [RELEASE] LTTng-UST 2.9.7 (EOL), 2.10.6 (Linux user-space tracer)
Date: Thu, 17 Oct 2019 16:01:07 -0400 (EDT)
Message-ID: <656595855.12717.1571342467573.JavaMail.zimbra@efficios.com> (raw)

Hi,

We are pleased to announce the 2.9.7 (EOL) and 2.10.6 stable releases
of the LTTng-UST 2.9 and 2.10 stable branches.

LTTng-UST, the Linux Trace Toolkit Next Generation Userspace Tracer,
is a low-overhead application tracer. The library "liblttng-ust" enables
tracing of applications and libraries.

* New in this release:

Important fixes to the lttng-ust fd tracker (liblttng-ust-fd.so) were done,
taking care of locking the fd tracker across fork() in the liblttng-ust-fork.so
wrapper, eliminating hangs observed in the child if the parent was executing
close() concurrently with fork(). Also, given that close() is an async-signal-safe
function, ensure that the synchronization strategy is robust against signals
by disabling signals and using a TLS nesting counter when taking the fd tracker
lock. [1, 2]

Another important fix to the lttng-ust fd tracker is disabling thread
cancellation around fd tracker lock, and locking the fd tracker across
fork() in the liblttng-ust-fork.so wrapper. Failure to do so causes
deadlocks in child applications if a pthread cancellation is performed
on a thread while it ran the liblttng-ust-fd close(3) wrapper. [3]

The locking strategy of the LTTng perf counter contexts was revisited to
eliminate a deadlock occurring once in a while when using the perf counters
context with lttng-ust. [4]

Now that the release of LTTng-UST 2.11.0 is imminent, version 2.9.7 marks
the end of life (EOL) of the 2.9 stable branch of LTTng-UST.

Thanks!

Mathieu

Project website: http://lttng.org
Documentation: http://lttng.org/docs
Download link: http://lttng.org/download

[1] https://bugs.lttng.org/issues/1199
[2] https://bugs.lttng.org/issues/1200
[3] https://bugs.lttng.org/issues/1201
[4] https://bugs.lttng.org/issues/1202

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

                 reply index

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=656595855.12717.1571342467573.JavaMail.zimbra@efficios.com \
    --to=mathieu.desnoyers@efficios.com \
    --cc=diamon-discuss@lists.linuxfoundation.org \
    --cc=linux-trace-users@vger.kernel.org \
    --cc=lttng-dev@lists.lttng.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Trace-Users Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-trace-users/0 linux-trace-users/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-trace-users linux-trace-users/ https://lore.kernel.org/linux-trace-users \
		linux-trace-users@vger.kernel.org
	public-inbox-index linux-trace-users

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-trace-users


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git