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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 11 Jun 2019 14:55:45 +0100 Received: from b01ledav003.gho.pok.ibm.com (b01ledav003.gho.pok.ibm.com [9.57.199.108]) by b01cxnp22035.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x5BDsUrJ35979632 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 11 Jun 2019 13:54:30 GMT Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0798FB2065; Tue, 11 Jun 2019 13:54:30 +0000 (GMT) Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EE1AEB2064; Tue, 11 Jun 2019 13:54:29 +0000 (GMT) Received: from paulmck-ThinkPad-W541 (unknown [9.85.164.193]) by b01ledav003.gho.pok.ibm.com (Postfix) with ESMTP; Tue, 11 Jun 2019 13:54:29 +0000 (GMT) Received: by paulmck-ThinkPad-W541 (Postfix, from userid 1000) id EC05116C2F18; Tue, 11 Jun 2019 06:54:29 -0700 (PDT) Date: Tue, 11 Jun 2019 06:54:29 -0700 From: "Paul E. McKenney" To: Dietmar Eggemann Cc: Mark Rutland , Peter Zijlstra , tglx@linutronix.de, mingo@kernel.org, jpoimboe@redhat.com, mojha@codeaurora.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH HACK RFC] cpu: Prevent late-arriving interrupts from disrupting offline Reply-To: paulmck@linux.ibm.com References: <20190602011253.GA6167@linux.ibm.com> <20190603083848.GB3436@hirez.programming.kicks-ass.net> <20190603114455.GA16119@lakrids.cambridge.arm.com> <20190604074549.GP28207@linux.ibm.com> <6eb5d59f-37d0-0aab-1fc0-fcf48cc4164f@arm.com> <20190608164158.GK28207@linux.ibm.com> <16a424d1-0ab7-7e81-5c4f-93da23519b1d@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <16a424d1-0ab7-7e81-5c4f-93da23519b1d@arm.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 19061113-0064-0000-0000-000003ECC39D X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00011246; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000286; SDB=6.01216451; UDB=6.00639598; IPR=6.00997550; MB=3.00027261; MTD=3.00000008; XFM=3.00000015; UTC=2019-06-11 13:55:48 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19061113-0065-0000-0000-00003DD9B8A3 Message-Id: <20190611135429.GH28207@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-06-11_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906110094 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 11, 2019 at 03:14:54PM +0200, Dietmar Eggemann wrote: > On 6/8/19 6:41 PM, Paul E. McKenney wrote: > >On Tue, Jun 04, 2019 at 03:29:32PM +0200, Dietmar Eggemann wrote: > >>On 6/4/19 9:45 AM, Paul E. McKenney wrote: > >>>On Mon, Jun 03, 2019 at 03:39:18PM +0200, Dietmar Eggemann wrote: > >>>>On 6/3/19 1:44 PM, Mark Rutland wrote: > >>>>>On Mon, Jun 03, 2019 at 10:38:48AM +0200, Peter Zijlstra wrote: > >>>>>>On Sat, Jun 01, 2019 at 06:12:53PM -0700, Paul E. McKenney wrote: > >>>>>>>Scheduling-clock interrupts can arrive late in the CPU-offline process, > > [...] > > >>>And it looks like the reason I dropped it was that I didn't get any > >>>response from the maintainer. I sent a message to this effect to > >>>linux-arm-kernel@lists.infradead.org and linux@arm.linux.org.uk on May > >>>21, 2015. > >>> > >>>So here it is again. ;-) > >>> > >>>I have queued this locally. Left to myself, I add the two of you on its > >>>Cc: list and run it through my normal process. But given the history, > >>>I would still want either an ack from the maintainer or, better, for > >>>the maintainer to take the patch. > >>> > >>>Or is there a better way for us to proceed on this? > >> > >>You could send this patch also to > >>linux-arm-kernel@lists.infradead.org and cc rmk to get his opinion > >>on the patch. > > > >OK, please let me know how the testing goes. My thought is to send the > >patch as you suggest with your Tested-by. > > Tested your patch on top of v5.2-rc4* on Arm TC2 (32bit) and CPU > hotplug stress test. W/o your patch, the test fails within seconds > since CPUs are not coming up again. W/ your patch, the test runs for > hours just fine. > > You can add my: > > Tested-by: Dietmar Eggemann Thank you!!! > * just for the record: one additional unrelated patch (to disable > the NOR flash) is necessary on Arm TC2: > https://patchwork.kernel.org/patch/10968391 . Is this progressing, or does it also need help getting to mainline? Left to myself, I will push my patch and assume that the NOR flash patch will make it in its own good time -- or, alternatively, that there is someone better positioned than me to push it. Thanx, Paul