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From: Vlastimil Babka <vbabka@suse.cz>
To: Michal Hocko <mhocko@kernel.org>
Cc: Baoquan He <bhe@redhat.com>, David Hildenbrand <david@redhat.com>,
	linux-mm@kvack.org, pifang@redhat.com,
	linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
	aarcange@redhat.com, Mel Gorman <mgorman@suse.de>,
	Hugh Dickins <hughd@google.com>
Subject: Re: Memory hotplug softlock issue
Date: Mon, 19 Nov 2018 17:48:35 +0100	[thread overview]
Message-ID: <6017b36f-3e29-c2ad-f2d1-2ebd77bbaef1@suse.cz> (raw)
In-Reply-To: <c7c20cc5-c2a4-ce61-3d97-56c8acfb13ec@suse.cz>

On 11/19/18 5:46 PM, Vlastimil Babka wrote:
> On 11/19/18 5:46 PM, Michal Hocko wrote:
>> On Mon 19-11-18 17:36:21, Vlastimil Babka wrote:
>>>
>>> So what protects us from locking a page whose refcount dropped to zero?
>>> and is being freed? The checks in freeing path won't be happy about a
>>> stray lock.
>>
>> Nothing really prevents that. But does it matter. The worst that might
>> happen is that we lock a freed or reused page. Who would complain?
> 
> free_pages_check() for example
> 
> PAGE_FLAGS_CHECK_AT_FREE includes PG_locked

And besides... what about the last page being offlined and then the
whole struct page's part of vmemmap destroyed as the node goes away?

  reply	other threads:[~2018-11-19 16:51 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-14  7:09 Memory hotplug softlock issue Baoquan He
2018-11-14  7:16 ` Baoquan He
2018-11-14  8:18 ` David Hildenbrand
2018-11-14  9:00   ` Baoquan He
2018-11-14  9:25     ` David Hildenbrand
2018-11-14  9:41       ` Michal Hocko
2018-11-14  9:48         ` David Hildenbrand
2018-11-14 10:04           ` Michal Hocko
2018-11-14  9:01   ` Michal Hocko
2018-11-14  9:22     ` David Hildenbrand
2018-11-14  9:37       ` Michal Hocko
2018-11-14  9:39         ` David Hildenbrand
2018-11-14 14:52     ` Baoquan He
2018-11-14 15:00       ` Michal Hocko
2018-11-15  5:10         ` Baoquan He
2018-11-15  7:30           ` Michal Hocko
2018-11-15  7:53             ` Baoquan He
2018-11-15  8:30               ` Michal Hocko
2018-11-15  9:42                 ` David Hildenbrand
2018-11-15  9:52                   ` Baoquan He
2018-11-15  9:53                     ` David Hildenbrand
2018-11-15 13:12                 ` Baoquan He
2018-11-15 13:19                   ` Michal Hocko
2018-11-15 13:23                     ` Baoquan He
2018-11-15 14:25                       ` Michal Hocko
2018-11-15 13:38                     ` Baoquan He
2018-11-15 14:32                       ` Michal Hocko
2018-11-15 14:34                         ` Baoquan He
2018-11-16  1:24                         ` Baoquan He
2018-11-16  9:14                           ` Michal Hocko
2018-11-17  4:22                             ` Baoquan He
2018-11-19 10:52                             ` Baoquan He
2018-11-19 12:40                               ` Michal Hocko
2018-11-19 12:51                                 ` Michal Hocko
2018-11-19 14:10                                   ` Michal Hocko
2018-11-19 16:36                                     ` Vlastimil Babka
2018-11-19 16:46                                       ` Michal Hocko
2018-11-19 16:46                                         ` Vlastimil Babka
2018-11-19 16:48                                           ` Vlastimil Babka [this message]
2018-11-19 17:01                                             ` Michal Hocko
2018-11-19 17:33                                     ` Michal Hocko
2018-11-19 20:34                                       ` Hugh Dickins
2018-11-19 20:59                                         ` Michal Hocko
2018-11-20  1:56                                           ` Baoquan He
2018-11-20  5:44                                             ` Hugh Dickins
2018-11-20 13:38                                               ` Vlastimil Babka
2018-11-20 13:58                                                 ` Baoquan He
2018-11-20 14:05                                                   ` Michal Hocko
2018-11-20 14:12                                                     ` Baoquan He
2018-11-21  1:21                                                   ` Hugh Dickins
2018-11-21  1:08                                                 ` Hugh Dickins
2018-11-21  3:20                                                   ` Hugh Dickins
2018-11-21 17:31                                               ` Michal Hocko
2018-11-22  1:53                                                 ` Hugh Dickins
2018-11-14 10:00 ` Michal Hocko

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