From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 41sLZP1YplzDqm6 for ; Fri, 17 Aug 2018 21:29:10 +1000 (AEST) Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w7HBNx8B135781 for ; Fri, 17 Aug 2018 07:29:08 -0400 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0a-001b2d01.pphosted.com with ESMTP id 2kwtv4x1b1-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 17 Aug 2018 07:29:08 -0400 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 17 Aug 2018 12:29:01 +0100 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> Message-Id: <20180817112850.GB3565@osiris> Content-Type: text/plain; charset=us-ascii List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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.