Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752077AbdLKVBp (ORCPT ); Mon, 11 Dec 2017 16:01:45 -0500 Received: from mail-ot0-f196.google.com ([74.125.82.196]:45085 "EHLO mail-ot0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751289AbdLKVBl (ORCPT ); Mon, 11 Dec 2017 16:01:41 -0500 X-Google-Smtp-Source: ACJfBot5Yyj5Y5DAbGZiMi2PVYC3TAbDUDYBpv/UjftWLCMR+uy4yw+klCEH7ArJHrJKgr3eqBpT+A== Subject: Re: [ANNOUNCE] 4.1.46-rt52 To: Julia Cartwright Cc: LKML , linux-rt-users , Steven Rostedt , Thomas Gleixner , Carsten Emde , John Kacur , Sebastian Andrzej Siewior , Daniel Wagner , tom.zanussi@linux.intel.com, Alex Shi References: <20171129231317.GB1361@jcartwri.amer.corp.natinst.com> <7b0d39d5-91ab-c8f0-bfec-7e26e71395bd@mvista.com> <20171211202017.GA19068@jcartwri.amer.corp.natinst.com> From: Corey Minyard Message-ID: Date: Mon, 11 Dec 2017 15:01:39 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <20171211202017.GA19068@jcartwri.amer.corp.natinst.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-GB Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4393 Lines: 104 On 12/11/2017 02:20 PM, Julia Cartwright wrote: > On Mon, Dec 11, 2017 at 01:04:58PM -0600, Corey Minyard wrote: >> On 11/29/2017 05:13 PM, Julia Cartwright wrote: >>> Hello RT Folks! >>> >>> I'm pleased to announce the 4.1.46-rt52 stable release. >>> >>> You can get this release via the git tree at: >>> >>> git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git >>> >>> branch: v4.1-rt >>> Head SHA1: 6e737a91c1ce923d4e10db831e14cfef9a2459cc >>> >>> Or to build 4.1.46-rt52 directly, the following patches should be applied: >>> >>> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.kernel.org_pub_linux_kernel_v4.x_linux-2D4.1.tar.xz&d=DwICaQ&c=I_0YwoKy7z5LMTVdyO6YCiE2uzI1jjZZuIPelcSjixA&r=cAXq_8W9Othb2h8ZcWv8Vw&m=a5KTpX9A0-pHwmQkOOLr5_xeWPavI-lgN7Z0Goes2So&s=tGmSNpZKEKvhTpeVu_ktmD4I5PIXfIJhZ79DxwbCjtQ&e= >>> >>> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.kernel.org_pub_linux_kernel_v4.x_patch-2D4.1.46.xz&d=DwICaQ&c=I_0YwoKy7z5LMTVdyO6YCiE2uzI1jjZZuIPelcSjixA&r=cAXq_8W9Othb2h8ZcWv8Vw&m=a5KTpX9A0-pHwmQkOOLr5_xeWPavI-lgN7Z0Goes2So&s=hx9pHgRy7tWhUeeiJhPOH0T8qdDrhtZvWxOWuIBZZgs&e= >>> >>> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.kernel.org_pub_linux_kernel_projects_rt_4.1_patch-2D4.1.46-2Drt52.patch.xz&d=DwICaQ&c=I_0YwoKy7z5LMTVdyO6YCiE2uzI1jjZZuIPelcSjixA&r=cAXq_8W9Othb2h8ZcWv8Vw&m=a5KTpX9A0-pHwmQkOOLr5_xeWPavI-lgN7Z0Goes2So&s=Pm8ed_xvW1drpPxNkt035bj6ILvSImuN9vvgEAt8IiM&e= >>> >>> >>> You can also build from 4.1.46-rt51 by applying the incremental patch: >>> >>> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.kernel.org_pub_linux_kernel_projects_rt_4.1_incr_patch-2D4.1.46-2Drt51-2Drt52.patch.xz&d=DwICaQ&c=I_0YwoKy7z5LMTVdyO6YCiE2uzI1jjZZuIPelcSjixA&r=cAXq_8W9Othb2h8ZcWv8Vw&m=a5KTpX9A0-pHwmQkOOLr5_xeWPavI-lgN7Z0Goes2So&s=ZM64-JCd0WNFQgFlB3wbCfn8Jtf9rq5QyCO2-GJsC2Q&e= >>> >>> Enjoy! >>> Julia >>> >>> Changes from v4.1.46-rt51: >>> --- >>> Julia Cartwright (2): >>> workqueue: fixup rcu check for RT >>> Linux 4.1.46-rt52 >>> >>> Sebastian Andrzej Siewior (2): >>> PM / CPU: replace raw_notifier with atomic_notifier (fixup) >> This change breaks the compile of 4.1 on ARM (and other things using >> kernel/cpu_pm.c). >> >> rcu_irq_enter_irqson() and friends doesn't exist in 4.1. In fact, >> rcu_irq_enter() doesn't even exist. >> >> Sorry I didn't get to testing this earlier, I've been focused on other things. > Thanks! My current builds apparently don't currently cover CPU_PM > builds, so I didn't see this :(. Thanks for the report. > > v4.1 does contain rcu_irq_enter(), and it looks like what we should be > using in 4.1 instead. Ah, it does, I looked in the wrong place. > I'm thinking the below should be okay; I'll be standing up a proper cpu > hotplugging test to give it some runtime. The below should work.  You'll need an ARM64, ARM or MIPS system with the proper config settings to exercise this code, though. -corey > Thanks, > Julia > > -- 8< -- > Subject: [PATCH] PM / CPU: replace usage of rcu_irq_{enter,exit}_irqson() > > Commit c50243950f97e ("PM / CPU: replace raw_notifier with > atomic_notifier (fixup)") intended to fix up RCU usage in idle, by > telling RCU to pay attention. > > However, the cherry-pick back from rt-devel included the invocation of > the _irqson() variants of rcu_irq_{enter,exit}() API which doesn't exist > in 4.1. > > For 4.1, just simply drop the _irqson() variant, and instead use > rcu_irq_{enter,exit}() directly instead. This is safe, because in 4.1, > these functions internally disable interrupts. > > Reported-by: Corey Minyard > Signed-off-by: Julia Cartwright --- > kernel/cpu_pm.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/cpu_pm.c b/kernel/cpu_pm.c > index d1d1c3961553..eeff3c382793 100644 > --- a/kernel/cpu_pm.c > +++ b/kernel/cpu_pm.c > @@ -33,10 +33,10 @@ static int cpu_pm_notify(enum cpu_pm_event event, int nr_to_call, int *nr_calls) > * could be disfunctional in cpu idle. Copy RCU_NONIDLE code to let > * RCU know this. > */ > - rcu_irq_enter_irqson(); > + rcu_irq_enter(); > ret = __atomic_notifier_call_chain(&cpu_pm_notifier_chain, event, NULL, > nr_to_call, nr_calls); > - rcu_irq_exit_irqson(); > + rcu_irq_exit(); > > return notifier_to_errno(ret); > }