From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
Peter Hurley <peter@hurleysoftware.com>,
Marc Gauthier <marc@cadence.com>,
Michael Cree <mcree@orcon.net.nz>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
David Laight <David.Laight@ACULAB.COM>,
Jakub Jelinek <jakub@redhat.com>,
"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
Tony Luck <tony.luck@intel.com>,
"linux-ia64@vger.kernel.org" <linux-ia64@vger.kernel.org>,
Oleg Nesterov <oleg@redhat.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Paul Mackerras <paulus@samba.org>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
Miroslav Franc <mfranc@redhat.com>,
Richard Henderson <rth@twiddle.net>,
"linux-alpha@vger.kernel.org" <linux-alpha@vger.kernel.org>
Subject: Re: bit fields && data tearing
Date: Fri, 5 Sep 2014 14:05:43 -0700 [thread overview]
Message-ID: <20140905210543.GC5001@linux.vnet.ibm.com> (raw)
In-Reply-To: <alpine.DEB.2.10.1409052247460.5472@nanos>
On Fri, Sep 05, 2014 at 10:48:34PM +0200, Thomas Gleixner wrote:
> On Fri, 5 Sep 2014, Paul E. McKenney wrote:
> > On Fri, Sep 05, 2014 at 01:34:52PM -0700, H. Peter Anvin wrote:
> > > On 09/05/2014 01:14 PM, Peter Hurley wrote:
> > > >
> > > > Here's how I read the two statements.
> > > >
> > > > First, the commit message:
> > > >
> > > > "It [this commit] documents that CPUs [supported by the Linux kernel]
> > > > _must provide_ atomic one-byte and two-byte naturally aligned loads and stores."
> > > >
> > > > Second, in the body of the document:
> > > >
> > > > "The Linux kernel no longer supports pre-EV56 Alpha CPUs, because these
> > > > older CPUs _do not provide_ atomic one-byte and two-byte loads and stores."
> > > >
> > >
> > > Does this apply in general or only to SMP configurations? I guess
> > > non-SMP configurations would still have problems if interrupted in the
> > > wrong place...
> >
> > And preemption could cause problems, too. So I believe that it needs
> > to be universal.
>
> Well preemption is usually caused by an interrupt, except you have a
> combined load and preempt instruction :)
Fair point! ;-)
Thanx, Paul
next prev parent reply other threads:[~2014-09-05 21:05 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20140712181328.GA8738@redhat.com>
[not found] ` <54079B70.4050200@hurleysoftware.com>
[not found] ` <1409785893.30640.118.camel@pasglop>
[not found] ` <063D6719AE5E284EB5DD2968C1650D6D17487172@AcuExch.aculab.com>
[not found] ` <1409824374.4246.62.camel@pasglop>
[not found] ` <5408E458.3@zytor.com>
2014-09-05 0:59 ` bit fields && data tearing Peter Hurley
2014-09-05 2:08 ` H. Peter Anvin
2014-09-05 8:16 ` Michael Cree
2014-09-05 18:09 ` Paul E. McKenney
2014-09-05 18:31 ` Paul E. McKenney
2014-09-05 19:52 ` Peter Zijlstra
2014-09-05 20:01 ` Peter Hurley
2014-09-05 20:12 ` Peter Zijlstra
2014-09-05 20:15 ` H. Peter Anvin
2014-09-05 20:19 ` Paul E. McKenney
2014-09-05 18:50 ` Peter Hurley
2014-09-05 19:05 ` Paul E. McKenney
2014-09-05 19:24 ` Peter Hurley
2014-09-05 20:09 ` Paul E. McKenney
2014-09-05 19:38 ` Marc Gauthier
2014-09-05 20:14 ` Peter Hurley
2014-09-05 20:34 ` H. Peter Anvin
2014-09-05 20:42 ` Michael Cree
2014-09-05 20:43 ` Paul E. McKenney
2014-09-05 20:48 ` Thomas Gleixner
2014-09-05 21:05 ` Paul E. McKenney [this message]
2014-09-05 20:39 ` Michael Cree
2014-09-05 21:12 ` Peter Hurley
2014-09-05 21:27 ` Michael Cree
2014-09-05 20:42 ` Paul E. McKenney
2014-09-05 2:08 ` H. Peter Anvin
2014-09-05 15:31 ` Peter Hurley
2014-09-05 15:41 ` H. Peter Anvin
2014-09-08 17:52 ` One Thousand Gnomes
2014-09-08 17:59 ` H. Peter Anvin
2014-09-08 19:17 ` One Thousand Gnomes
2014-09-09 11:18 ` Peter Hurley
2014-09-08 22:47 ` Peter Hurley
2014-09-09 1:59 ` Paul E. McKenney
2014-09-09 11:14 ` Peter Hurley
2014-09-11 10:04 ` One Thousand Gnomes
2014-09-11 16:16 ` Paul E. McKenney
2014-09-11 20:01 ` Peter Hurley
2014-09-14 23:24 ` One Thousand Gnomes
2014-09-22 19:51 ` Paul E. McKenney
2014-09-23 18:19 ` Peter Hurley
2014-09-23 18:39 ` One Thousand Gnomes
2014-09-08 18:13 ` James Bottomley
2014-09-10 20:18 ` H. Peter Anvin
2014-09-10 21:10 ` Rob Landley
[not found] ` <21512.10628.412205.873477@gargle.gargle.HOWL>
[not found] ` <20140904090952.GW17454@tucnak.redhat.com>
[not found] ` <540859EC.5000407@hurleysoftware.com>
[not found] ` <20140904175044.4697aee4@alan.etchedpixels.co.uk>
[not found] ` <5408C0AB.6050801@hurleysoftware.com>
[not found] ` <5408E4A3.2060303@zytor.com>
[not found] ` <20140905001751.GL5001@linux.vnet.ibm.com>
2014-09-05 1:57 ` Peter Hurley
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=20140905210543.GC5001@linux.vnet.ibm.com \
--to=paulmck@linux.vnet.ibm.com \
--cc=David.Laight@ACULAB.COM \
--cc=benh@kernel.crashing.org \
--cc=hpa@zytor.com \
--cc=jakub@redhat.com \
--cc=linux-alpha@vger.kernel.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-ia64@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=marc@cadence.com \
--cc=mcree@orcon.net.nz \
--cc=mfranc@redhat.com \
--cc=oleg@redhat.com \
--cc=paulus@samba.org \
--cc=peter@hurleysoftware.com \
--cc=rth@twiddle.net \
--cc=tglx@linutronix.de \
--cc=tony.luck@intel.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;
as well as URLs for NNTP newsgroup(s).