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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Fri, 17 Aug 2018 12:28:53 +0100 Received: from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com [9.149.105.60]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w7HBSqAx35782854 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 17 Aug 2018 11:28:52 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id DCB0A4203F; Fri, 17 Aug 2018 14:28:56 +0100 (BST) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3F8264204B; Fri, 17 Aug 2018 14:28:56 +0100 (BST) Received: from osiris (unknown [9.152.212.24]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Fri, 17 Aug 2018 14:28:56 +0100 (BST) Date: Fri, 17 Aug 2018 13:28:50 +0200 From: Heiko Carstens To: David Hildenbrand Cc: Greg Kroah-Hartman , "Rafael J. Wysocki" , Michal Hocko , Benjamin Herrenschmidt , Linux Memory Management List , Paul Mackerras , linux-s390@vger.kernel.org, sthemmin@microsoft.com, Pavel Tatashin , ACPI Devel Maling List , David Rientjes , xen-devel@lists.xenproject.org, Len Brown , haiyangz@microsoft.com, Dan Williams , Andrew Morton , Vlastimil Babka , osalvador@suse.de, "Rafael J. Wysocki" , Linux Kernel Mailing List , Martin Schwidefsky , devel@linuxdriverproject.org, Vitaly Kuznetsov , linuxppc-dev Subject: Re: [PATCH RFC 1/2] drivers/base: export lock_device_hotplug/unlock_device_hotplug References: <20180817075901.4608-1-david@redhat.com> <20180817075901.4608-2-david@redhat.com> <20180817084146.GB14725@kroah.com> <5a5d73e9-e4aa-ffed-a2e3-8aef64e61923@redhat.com> <42df9062-f647-3ad6-5a07-be2b99531119@redhat.com> <20180817100604.GA18164@kroah.com> <4ac624be-d2d6-5975-821f-b20a475781dc@redhat.com> MIME-Version: 1.0 In-Reply-To: <4ac624be-d2d6-5975-821f-b20a475781dc@redhat.com> X-TM-AS-GCONF: 00 x-cbid: 18081711-0028-0000-0000-000002EC2435 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18081711-0029-0000-0000-000023A552FC Message-Id: <20180817112850.GB3565@osiris> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit Content-Disposition: inline X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-08-17_03:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 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=8.0.1-1807170000 definitions=main-1808170125 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 17, 2018 at 01:04:58PM +0200, David Hildenbrand wrote: > >> If there are no objections, I'll go into that direction. But I'll wait > >> for more comments regarding the general concept first. > > > > It is the middle of the merge window, and maintainers are really busy > > right now. I doubt you will get many review comments just yet... > > > > This has been broken since 2015, so I guess it can wait a bit :) I hope you figured out what needs to be locked why. Your patch description seems to be "only" about locking order ;) I tried to figure out and document that partially with 55adc1d05dca ("mm: add private lock to serialize memory hotplug operations"), and that wasn't easy to figure out. I was especially concerned about sprinkling lock/unlock_device_hotplug() calls, which has the potential to make it the next BKL thing.