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From: Michal Hocko <mhocko@kernel.org>
To: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: "Pasha Tatashin" <pavel.tatashin@microsoft.com>,
	linux-nvdimm <linux-nvdimm@lists.01.org>,
	"Dave Hansen" <dave.hansen@intel.com>,
	"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
	"Ingo Molnar" <mingo@kernel.org>, "Linux MM" <linux-mm@kvack.org>,
	"Jérôme Glisse" <jglisse@redhat.com>,
	rppt@linux.vnet.ibm.com,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: Re: [PATCH v5 4/4] mm: Defer ZONE_DEVICE page initialization to the point where we init pgmap
Date: Wed, 10 Oct 2018 20:52:42 +0200	[thread overview]
Message-ID: <20181010185242.GP5873@dhcp22.suse.cz> (raw)
In-Reply-To: <98c35e19-13b9-0913-87d9-b3f1ab738b61@linux.intel.com>

On Wed 10-10-18 10:39:01, Alexander Duyck wrote:
> On 10/10/2018 10:24 AM, Michal Hocko wrote:
[...]
> > I thought I have already made it clear that these zone device hacks are
> > not acceptable to the generic hotplug code. If the current reserve bit
> > handling is not correct then give us a specific reason for that and we
> > can start thinking about the proper fix.
> 
> I might have misunderstood your earlier comment then. I thought you were
> saying that we shouldn't bother with setting the reserved bit. Now it sounds
> like you were thinking more along the lines of what I was here in my comment
> where I thought the bit should be cleared later in some code specifically
> related to DAX when it is exposing it for use to userspace or KVM.

It seems I managed to confuse myself completely. Sorry, it's been a long
day and I am sick so the brain doesn't work all that well. I will get
back to this tomorrow or on Friday with a fresh brain.

My recollection was that we do clear the reserved bit in
move_pfn_range_to_zone and we indeed do in __init_single_page. But then
we set the bit back right afterwards. This seems to be the case since
d0dc12e86b319 which reorganized the code. I have to study this some more
obviously.

-- 
Michal Hocko
SUSE Labs
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm

WARNING: multiple messages have this Message-ID (diff)
From: Michal Hocko <mhocko@kernel.org>
To: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: "Dan Williams" <dan.j.williams@intel.com>,
	"Linux MM" <linux-mm@kvack.org>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
	linux-nvdimm <linux-nvdimm@lists.01.org>,
	"Pasha Tatashin" <pavel.tatashin@microsoft.com>,
	"Dave Hansen" <dave.hansen@intel.com>,
	"Jérôme Glisse" <jglisse@redhat.com>,
	rppt@linux.vnet.ibm.com, "Ingo Molnar" <mingo@kernel.org>,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	yi.z.zhang@linux.intel.com
Subject: Re: [PATCH v5 4/4] mm: Defer ZONE_DEVICE page initialization to the point where we init pgmap
Date: Wed, 10 Oct 2018 20:52:42 +0200	[thread overview]
Message-ID: <20181010185242.GP5873@dhcp22.suse.cz> (raw)
In-Reply-To: <98c35e19-13b9-0913-87d9-b3f1ab738b61@linux.intel.com>

On Wed 10-10-18 10:39:01, Alexander Duyck wrote:
> On 10/10/2018 10:24 AM, Michal Hocko wrote:
[...]
> > I thought I have already made it clear that these zone device hacks are
> > not acceptable to the generic hotplug code. If the current reserve bit
> > handling is not correct then give us a specific reason for that and we
> > can start thinking about the proper fix.
> 
> I might have misunderstood your earlier comment then. I thought you were
> saying that we shouldn't bother with setting the reserved bit. Now it sounds
> like you were thinking more along the lines of what I was here in my comment
> where I thought the bit should be cleared later in some code specifically
> related to DAX when it is exposing it for use to userspace or KVM.

It seems I managed to confuse myself completely. Sorry, it's been a long
day and I am sick so the brain doesn't work all that well. I will get
back to this tomorrow or on Friday with a fresh brain.

My recollection was that we do clear the reserved bit in
move_pfn_range_to_zone and we indeed do in __init_single_page. But then
we set the bit back right afterwards. This seems to be the case since
d0dc12e86b319 which reorganized the code. I have to study this some more
obviously.

-- 
Michal Hocko
SUSE Labs

  parent reply	other threads:[~2018-10-10 18:52 UTC|newest]

Thread overview: 144+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-25 20:18 [PATCH v5 0/4] Address issues slowing persistent memory initialization Alexander Duyck
2018-09-25 20:18 ` Alexander Duyck
2018-09-25 20:19 ` [PATCH v5 1/4] mm: Remove now defunct NO_BOOTMEM from depends list for deferred init Alexander Duyck
2018-09-25 20:19   ` Alexander Duyck
2018-09-25 21:05   ` Mike Rapoport
2018-09-25 21:05     ` Mike Rapoport
2018-09-25 20:20 ` [PATCH v5 2/4] mm: Provide kernel parameter to allow disabling page init poisoning Alexander Duyck
2018-09-25 20:20   ` Alexander Duyck
2018-09-25 20:26   ` Dave Hansen
2018-09-25 20:26     ` Dave Hansen
2018-09-25 20:38     ` Alexander Duyck
2018-09-25 20:38       ` Alexander Duyck
2018-09-25 22:14       ` Dave Hansen
2018-09-25 22:14         ` Dave Hansen
2018-09-25 22:14         ` Dave Hansen
2018-09-25 22:27         ` Alexander Duyck
2018-09-25 22:27           ` Alexander Duyck
2018-09-25 22:27           ` Alexander Duyck
2018-09-26  7:38   ` Michal Hocko
2018-09-26  7:38     ` Michal Hocko
2018-09-26 15:24     ` Alexander Duyck
2018-09-26 15:39       ` Michal Hocko
2018-09-26 15:39         ` Michal Hocko
2018-09-26 15:41       ` Dave Hansen
2018-09-26 15:41         ` Dave Hansen
2018-09-26 16:18         ` Alexander Duyck
2018-09-26 15:36     ` Dave Hansen
2018-09-26 22:36       ` Andrew Morton
2018-09-26 22:36         ` Andrew Morton
2018-09-25 20:20 ` [PATCH v5 3/4] mm: Create non-atomic version of SetPageReserved for init use Alexander Duyck
2018-09-25 20:20   ` Alexander Duyck
2018-09-25 20:21 ` [PATCH v5 4/4] mm: Defer ZONE_DEVICE page initialization to the point where we init pgmap Alexander Duyck
2018-09-25 20:21   ` Alexander Duyck
2018-09-26  7:55   ` Michal Hocko
2018-09-26 18:25     ` Alexander Duyck
2018-09-26 18:25       ` Alexander Duyck
2018-09-26 18:52       ` Dan Williams
2018-09-26 18:52         ` Dan Williams
2018-09-27 11:20         ` Michal Hocko
2018-09-27 11:20           ` Michal Hocko
2018-09-27 11:09       ` Michal Hocko
2018-09-27 11:09         ` Michal Hocko
2018-09-27 12:25         ` Oscar Salvador
2018-09-27 13:13           ` Michal Hocko
2018-09-27 14:50             ` Oscar Salvador
2018-09-27 14:50               ` Oscar Salvador
2018-09-27 14:50               ` Oscar Salvador
2018-09-27 15:41               ` David Hildenbrand
2018-09-27 15:41                 ` David Hildenbrand
2018-09-28  8:12             ` Oscar Salvador
2018-09-28  8:12               ` Oscar Salvador
2018-09-28  8:44               ` Oscar Salvador
2018-09-28  8:44                 ` Oscar Salvador
2018-09-28 15:50                 ` Dan Williams
2018-09-28 15:50                   ` Dan Williams
2018-09-27 12:32       ` Oscar Salvador
2018-10-08 21:01   ` Dan Williams
2018-10-08 21:01     ` Dan Williams
2018-10-08 21:38     ` Alexander Duyck
2018-10-08 21:38       ` Alexander Duyck
2018-10-08 22:00       ` Dan Williams
2018-10-08 22:00         ` Dan Williams
2018-10-08 22:00         ` Dan Williams
2018-10-08 22:07         ` Alexander Duyck
2018-10-08 22:07           ` Alexander Duyck
2018-10-08 22:36         ` Alexander Duyck
2018-10-08 22:36           ` Alexander Duyck
2018-10-08 22:59           ` Dan Williams
2018-10-08 23:34     ` [mm PATCH] memremap: Fix reference count for pgmap in devm_memremap_pages Alexander Duyck
2018-10-08 23:34       ` Alexander Duyck
2018-10-09  0:20       ` Dan Williams
2018-10-09  0:20         ` Dan Williams
2018-10-09 17:00   ` [PATCH v5 4/4] mm: Defer ZONE_DEVICE page initialization to the point where we init pgmap Yi Zhang
2018-10-09 17:00     ` Yi Zhang
2018-10-09 18:04     ` Dan Williams
2018-10-09 18:04       ` Dan Williams
2018-10-09 20:26       ` Alexander Duyck
2018-10-09 20:26         ` Alexander Duyck
2018-10-09 21:19         ` Dan Williams
2018-10-09 21:19           ` Dan Williams
2018-10-10 12:52           ` Yi Zhang
2018-10-10 12:52             ` Yi Zhang
2018-10-10 15:27             ` Alexander Duyck
2018-10-10 15:27               ` Alexander Duyck
2018-10-11  8:17               ` Yi Zhang
2018-10-11  8:17                 ` Yi Zhang
2018-10-10  9:58         ` Michal Hocko
2018-10-10 16:39           ` Alexander Duyck
2018-10-10 16:39             ` Alexander Duyck
2018-10-10 17:24             ` Michal Hocko
2018-10-10 17:24               ` Michal Hocko
2018-10-10 17:39               ` Alexander Duyck
2018-10-10 17:39                 ` Alexander Duyck
2018-10-10 17:53                 ` Michal Hocko
2018-10-10 17:53                   ` Michal Hocko
2018-10-10 18:13                   ` Alexander Duyck
2018-10-10 18:13                     ` Alexander Duyck
2018-10-10 18:52                 ` Michal Hocko [this message]
2018-10-10 18:52                   ` Michal Hocko
2018-10-11  8:55                   ` Michal Hocko
2018-10-11  8:55                     ` Michal Hocko
2018-10-11 17:38                     ` Alexander Duyck
2018-10-11 18:22                       ` Dan Williams
2018-10-11 18:22                         ` Dan Williams
2018-10-17  7:52                       ` Michal Hocko
2018-10-17  7:52                         ` Michal Hocko
2018-10-17 15:02                         ` Alexander Duyck
2018-10-17 15:02                           ` Alexander Duyck
2018-10-29 14:12                           ` Michal Hocko
2018-10-29 14:12                             ` Michal Hocko
2018-10-29 15:59                             ` Alexander Duyck
2018-10-29 15:59                               ` Alexander Duyck
2018-10-29 15:59                               ` Alexander Duyck
2018-10-29 16:35                               ` Michal Hocko
2018-10-29 16:35                                 ` Michal Hocko
2018-10-29 17:01                                 ` Alexander Duyck
2018-10-29 17:24                                   ` Michal Hocko
2018-10-29 17:24                                     ` Michal Hocko
2018-10-29 17:34                                     ` Dan Williams
2018-10-29 17:34                                       ` Dan Williams
2018-10-29 17:45                                       ` Michal Hocko
2018-10-29 17:45                                         ` Michal Hocko
2018-10-29 17:42                                     ` Alexander Duyck
2018-10-29 17:42                                       ` Alexander Duyck
2018-10-29 18:18                                       ` Michal Hocko
2018-10-29 18:18                                         ` Michal Hocko
2018-10-29 19:59                                         ` Alexander Duyck
2018-10-29 19:59                                           ` Alexander Duyck
2018-10-30  6:29                                           ` Michal Hocko
2018-10-30  6:29                                             ` Michal Hocko
2018-10-30  6:55                                             ` Dan Williams
2018-10-30  8:17                                               ` Michal Hocko
2018-10-30  8:17                                                 ` Michal Hocko
2018-10-30 15:57                                                 ` Dan Williams
2018-10-30  8:05                                           ` Oscar Salvador
2018-10-29 15:49                           ` Dan Williams
2018-10-29 15:49                             ` Dan Williams
2018-10-29 15:56                             ` Michal Hocko
2018-10-10 18:18               ` Dan Williams
2018-10-10 18:18                 ` Dan Williams
2018-10-11  8:39                 ` Yi Zhang
2018-10-11  8:39                   ` Yi Zhang
2018-10-11 15:38                   ` Alexander Duyck
2018-10-11 15:38                     ` Alexander Duyck

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