Mirror of the lttng-dev mailing list
 help / color / mirror / Atom feed
From: Paul_Woegerer@mentor.com (Woegerer, Paul)
Subject: [lttng-dev] baddr feature triggers deadlock in lttng-ust
Date: Fri, 28 Feb 2014 13:38:55 +0100	[thread overview]
Message-ID: <5310835F.10909@mentor.com> (raw)
In-Reply-To: <561294755.31915.1393536606539.JavaMail.zimbra@efficios.com>

I have looked a bit into the issue...

The ust_locking inside the dl_iterate_phdr triggers the deadlock.

If I just collect the base address info inside dl_iterate_phdr and dump
the collected data with trace_baddr afterwards (outside the
dl_iterate_phdr iteration) the deadlock will be prevented.

I'm now going to create a patch that implements this approach.

Thanks,
Paul

On 02/27/2014 10:30 PM, Mathieu Desnoyers wrote:
> Hi Paul,
>
> Please see http://bugs.lttng.org/issues/745, which explains a deadlock
> we just found out.
>
> We might have to disable the baddr dump feature, since our release is
> tomorrow. We'll have to re-think our locking to protect operations
> using the dynamic loader lock against fork, clone, and daemon.
>
> Thanks,
>
> Mathieu
>


-- 
Paul Woegerer, SW Development Engineer
Sourcery Analyzer <http://go.mentor.com/sourceryanalyzer>
Mentor Graphics, Embedded Software Division




  parent reply	other threads:[~2014-02-28 12:38 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1640835527.31912.1393536374130.JavaMail.zimbra@efficios.com>
2014-02-27 21:30 ` Mathieu Desnoyers
2014-02-27 23:37   ` Alexandre Montplaisir
2014-02-28  0:07     ` Mathieu Desnoyers
2014-02-28  9:33   ` Woegerer, Paul
2014-02-28 12:38   ` Woegerer, Paul [this message]
2014-02-28 14:05     ` Mathieu Desnoyers

Reply instructions:

You may reply publicly 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=5310835F.10909@mentor.com \
    --to=paul_woegerer@mentor.com \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox