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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.