From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754103Ab3CVDZN (ORCPT ); Thu, 21 Mar 2013 23:25:13 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:37673 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751464Ab3CVDZM (ORCPT ); Thu, 21 Mar 2013 23:25:12 -0400 Message-ID: <1363922685.3728.21.camel@deadeye.wl.decadent.org.uk> Subject: Re: PREEMPT_RT vs 'hrtimer: Prevent hrtimer_enqueue_reprogram race' From: Ben Hutchings To: Steven Rostedt Cc: Thomas Gleixner , Peter Zijlstra , Steven Rostedt , LKML , Leonid Shatz , Ingo Molnar , Debian kernel maintainers Date: Fri, 22 Mar 2013 03:24:45 +0000 In-Reply-To: <1363919473.6345.88.camel@gandalf.local.home> References: <1363914713.31336.191.camel@deadeye.wl.decadent.org.uk> <1363919473.6345.88.camel@gandalf.local.home> Content-Type: multipart/signed; micalg="pgp-sha512"; protocol="application/pgp-signature"; boundary="=-LHxlsCY0lY0WWjEFg7Vn" X-Mailer: Evolution 3.4.4-2 Mime-Version: 1.0 X-SA-Exim-Connect-IP: 2001:470:1f08:1539:9535:520b:eb30:917a X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-LHxlsCY0lY0WWjEFg7Vn Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2013-03-21 at 22:31 -0400, Steven Rostedt wrote: > On Fri, 2013-03-22 at 01:11 +0000, Ben Hutchings wrote: > > Commit b22affe0aef4 'hrtimer: Prevent hrtimer_enqueue_reprogram race' > > conflicts with the RT patches > > hrtimer-fixup-hrtimer-callback-changes-for-preempt-r.patch and > > peter_zijlstra-frob-hrtimer.patch, as they all change > > hrtimer_enqueue_reprogram(). It seems that the changes in the RT > > patches now belong in __hrtimer_start_range_ns(). > >=20 > > Since I haven't seen any RT releases in a while, here's what I came up > > with for 3.2-rt: >=20 > Note, I posted a fix on Tuesday: >=20 > https://lkml.org/lkml/2013/3/19/369 Thanks. I did search GMANE with some obvious terms but I think its index is lagging. > I'm waiting for Thomas to give his OK on it before releasing the series. > He told me he'll have a look at it tomorrow. I've already ran the series > through all my tests, and will post it immediately after I get the OK. > Or if there's a issue I will have to fix it and rerun my tests. >=20 >=20 > >=20 > > --- > > From: Thomas Gleixner > > Date: Fri, 3 Jul 2009 08:44:31 -0500 > > Subject: hrtimer: fixup hrtimer callback changes for preempt-rt [...] > > @@ -1011,6 +1023,26 @@ int __hrtimer_start_range_ns(struct hrti > > */ > > if (leftmost && new_base->cpu_base =3D=3D &__get_cpu_var(hrtimer_base= s) > > && hrtimer_enqueue_reprogram(timer, new_base)) { > > +#ifdef CONFIG_PREEMPT_RT_BASE > > + again: >=20 > What kernel are you working with? I don't see anywhere the "again:" > within a PREEMPT_RT_BASE block. I'm rebasing the rt patch series generated with 'git format-patch v3.2.39..v3.2.39-rt59-rebase' on top of v3.2.41 (plus Debian changes, which introduce some trivial textual conflicts). So these patches were previously: commit c495d005449523772e27a22fb74814dc3cebff8e Author: Thomas Gleixner Date: Fri Jul 3 08:44:31 2009 -0500 hrtimer: fixup hrtimer callback changes for preempt-rt commit 80cc960e628509c72f63a7327a4dc22707a02b81 Author: Peter Zijlstra Date: Fri Aug 12 17:39:54 2011 +0200 hrtimer: Don't call the timer handler from hrtimer_start [...] > This is very similar to what I came up with. [...] > Yep, looks like we are on the right track :-) [...] Good to hear. Ben. --=20 Ben Hutchings Make three consecutive correct guesses and you will be considered an expert= . --=-LHxlsCY0lY0WWjEFg7Vn Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIVAwUAUUvO/ee/yOyVhhEJAQqEMQ/7BRsyB7tf8HV/uEwemk++ojQAtIZfZMrA cjkQkbbi/GsYHxz5FqXu0X+FzeZUdz+G/oLQxRlmNGqEFUo4pURCysiuiLHgv4ml e/RHbWpAFoT/zaAcjvTeWChmw8zgsKiSBlXY5+RTksyEXv9zmGXgpabhQxk3CRPm mCNNuRsF+lpB5d45rZY5LPXhedyWzS2WivCk3Ix+eIrTvOjO/HgCJ0wKy+hfDtfG uxEIW3J2J99J8GrvElXIB4ZneGfRmvJLC3a70Se1tgKhG3GsRgR46I/XS2+HIVoS MCdiKoH4UKhlyu1yuJFJSCtStH8loMub/k5sn50B7EraxX/vBWdhJ3SHbh4w1DEs 9+sEQuFTo71gEvb/CWwqY3XDW217QORzgjcQtOdqYqz2GjTK2TFko6Nwp0+PfaIq Eq8QFBCBLrJSqY3MXeB/yjbrAdHuQ9zUGrxPWHoVxO0Vk2ynSHRnk5M7TxT5GGHH bRS5Bjx+1VyiwwWXPsZMAtM2wFzw+p1gVrKFw7H191xCTCQcvUVbxh3yXztZz1gT RhdWpJnIiGiQDk66zePSyuK59T80cTmFY6RjdCeVvVuhRfq3EVJd8VifydQ48z21 2av0NCX4Rqj4JXjYDwcDYXLN9g/paNa/QHyHn0Ix2Il2l+WtP/FGcCmiiP2VbNv/ J6VMlwlZZK8= =ZffS -----END PGP SIGNATURE----- --=-LHxlsCY0lY0WWjEFg7Vn--