From owner-freebsd-hackers@FreeBSD.ORG  Thu Aug  5 16:01:24 2010
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id F2D651065677;
	Thu,  5 Aug 2010 16:01:23 +0000 (UTC)
	(envelope-from mdf356@gmail.com)
Received: from mail-pw0-f54.google.com (mail-pw0-f54.google.com
	[209.85.160.54])
	by mx1.freebsd.org (Postfix) with ESMTP id B49D18FC29;
	Thu,  5 Aug 2010 16:01:23 +0000 (UTC)
Received: by pwj4 with SMTP id 4so146938pwj.13
	for <multiple recipients>; Thu, 05 Aug 2010 09:01:23 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma;
	h=domainkey-signature:mime-version:received:sender:received
	:in-reply-to:references:date:x-google-sender-auth:message-id:subject
	:from:to:cc:content-type:content-transfer-encoding;
	bh=xbN1Fv55Pv2Qqf9Y1GMeInfDdiE+MyMyPYBzSM87bT0=;
	b=xQ8ltdfuoYujW2Stw09sJS7qzDQgn5ym1qlOQr5YjPLOppbwnUJn7GmvNw5Fehe98g
	hNq2S+gzFKvPlV8Z5xxTGg8ZS4q0sABYdBa3g7YCK193oW9V1oQ/sM1JsOLBe2U9EV2x
	0jEUdObhegVfTpIGZkCo1b9Maw+kWdIPPdAO8=
DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma;
	h=mime-version:sender:in-reply-to:references:date
	:x-google-sender-auth:message-id:subject:from:to:cc:content-type
	:content-transfer-encoding;
	b=KeggLZ6692lO5kOXwACPl8xZBMH5qfvlazOKys+WdyHmwhY9gMbDN/wMLzG/8tWC6O
	U6mAX2eY8IJFaa2R7CjMH75+CXGvreiWXk6I19Ag/fk6s+fdK+qpGN6/pSBUJMsN1KWz
	8l8V8XqcXnOb7C4VZiJUPZXpQnhZS9eJzxYC0=
MIME-Version: 1.0
Received: by 10.114.38.6 with SMTP id l6mr12485570wal.47.1281024082601; Thu, 
	05 Aug 2010 09:01:22 -0700 (PDT)
Sender: mdf356@gmail.com
Received: by 10.42.3.140 with HTTP; Thu, 5 Aug 2010 09:01:22 -0700 (PDT)
In-Reply-To: <AANLkTi=YjbBdZp9KuGUmMuYUmWyx_n+ykikPSMMMo=j9@mail.gmail.com>
References: <AANLkTikY20TxyeyqO5zP3zC-azb748kV-MdevPfm+8cq@mail.gmail.com>
	<201007301031.34266.jhb@freebsd.org>
	<AANLkTinp7278ZD1L8s616seQET=OQBx1RZ4eHx=e+pD5@mail.gmail.com>
	<201008041026.17553.jhb@freebsd.org>
	<AANLkTi=YjbBdZp9KuGUmMuYUmWyx_n+ykikPSMMMo=j9@mail.gmail.com>
Date: Thu, 5 Aug 2010 09:01:22 -0700
X-Google-Sender-Auth: yzOmpixTq9gMWJC5q2S6SJcAAkA
Message-ID: <AANLkTimD6fMLazWwA1bMZZJCKSHdL5v-4kc1wCSVQoMZ@mail.gmail.com>
From: mdf@FreeBSD.org
To: mdf@freebsd.org
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable
Cc: freebsd-hackers@freebsd.org
Subject: Re: sched_pin() versus PCPU_GET
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 05 Aug 2010 16:01:24 -0000

On Wed, Aug 4, 2010 at 9:20 AM,  <mdf@freebsd.org> wrote:
> On Wed, Aug 4, 2010 at 2:26 PM, John Baldwin <jhb@freebsd.org> wrote:
>> Actually, I would beg to differ in that case. =A0If PCPU_GET(spinlocks)
>> returns non-NULL, then it means that you hold a spin lock,
>
> ll_count is 0 for the "correct" pc_spinlocks and non-zero for the
> "wrong" one, though. =A0So I think it can be non-NULL but the current
> thread/CPU doesn't hold a spinlock.
>
> I don't believe we have any code in the NMI handler. =A0I'm on vacation
> today so I'll check tomorrow.

I checked and ipi_nmi_handler() doesn't appear to have any local
changes.  I assume that's where I should look?

Thanks,
matthew