From: Peter Zijlstra <peterz@infradead.org>
To: Tony Lu <zlu@tilera.com>
Cc: Paul Mackerras <paulus@samba.org>, Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@ghostprotocols.net>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Chris Metcalf <cmetcalf@tilera.com>
Subject: Re: [BUG] perf: can not resolve symbols for forked threads
Date: Tue, 24 Jun 2014 12:42:13 +0200 [thread overview]
Message-ID: <20140624104213.GL19860@laptop.programming.kicks-ass.net> (raw)
In-Reply-To: <BAB94DBB0E89D8409949BC28AC95914C5D76499C@USMAExch1.tad.internal.tilera.com>
On Tue, Jun 24, 2014 at 06:47:38AM +0000, Tony Lu wrote:
> >That pthread_exit() is the problem; this results in:
> >
> >29456 pts/23 Zl 0:00 | \_ [hello] <defunct>
> >
> >You want to wait for the threads to complete using pthread_join().
> >
> >I suspect the defunct state hides the process.
>
> Yes, using pthread_join() can workaround this problem.
> Does that mean the parent thread can not exit before the child threads? It still seems like a perf bug.
So we scan /proc at record start to acquire the state for the existing
tasks, it might be defunct tasks simply aren't there anymore, in which
case there's nothing we can do.
But I haven't checked..
That said, yes it would be nice if we could cure this.
prev parent reply other threads:[~2014-06-24 10:42 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-19 7:39 Tony Lu
2014-06-23 9:12 ` Peter Zijlstra
2014-06-24 6:47 ` Tony Lu
2014-06-24 10:42 ` Peter Zijlstra [this message]
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=20140624104213.GL19860@laptop.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=acme@ghostprotocols.net \
--cc=cmetcalf@tilera.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=paulus@samba.org \
--cc=zlu@tilera.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
all inboxes | Powered by JetHome®