From: Lee Revell <rlrevell@joe-job.com>
To: Mike Kravetz <kravetz@us.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
John Levon <levon@movementarian.org>,
phil.el@wanadoo.fr, Ingo Molnar <mingo@elte.hu>,
linux-kernel@vger.kernel.org,
oprofile-list@lists.sourceforge.net, george@mvista.com
Subject: Re: oprofile can cause an NMI to schedule (was: [RT] scheduling and oprofile)
Date: Wed, 25 Oct 2006 15:52:59 -0400 [thread overview]
Message-ID: <1161805980.3982.319.camel@mindpipe> (raw)
In-Reply-To: <20061025185813.GA4114@monkey.ibm.com>
On Wed, 2006-10-25 at 11:58 -0700, Mike Kravetz wrote:
> Newer RT kernels (such as linux-2.6.18-rt5) have reenabled the
> add_preempt_count/sub_preempt_count calls in nmi_enter/exit. If I
> understand correctly the reason one could not modify the preempt_count
> from NMI code is that it could have been in the process of being
> modified by non-NMI code. But, in recent RT kernels it appears that
> preempt_count is still a single word modified by both NMI and
> non-NMI code. What am I missing that now makes this safe?
>
It's not safe. NMI causes hard lockups on 2.6.18-rt5. Get 2.6.18-rt7.
Lee
prev parent reply other threads:[~2006-10-25 19:53 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-10-23 21:23 [RT] scheduling and oprofile Mike Kravetz
2006-10-24 2:24 ` oprofile can cause an NMI to schedule (was: [RT] scheduling and oprofile) Steven Rostedt
2006-10-24 12:46 ` John Levon
2006-10-24 12:54 ` Steven Rostedt
2006-10-25 18:58 ` Mike Kravetz
2006-10-25 19:52 ` Lee Revell [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=1161805980.3982.319.camel@mindpipe \
--to=rlrevell@joe-job.com \
--cc=george@mvista.com \
--cc=kravetz@us.ibm.com \
--cc=levon@movementarian.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=oprofile-list@lists.sourceforge.net \
--cc=phil.el@wanadoo.fr \
--cc=rostedt@goodmis.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
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