From: Michal Hocko <mhocko@suse.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>,
linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>
Subject: uninitialized pmem struct pages
Date: Mon, 4 Jan 2021 11:03:23 +0100 [thread overview]
Message-ID: <20210104100323.GC13207@dhcp22.suse.cz> (raw)
Hi,
back in March [1] you have recommended 53cdc1cb29e8
("drivers/base/memory.c: indicate all memory blocks as removable") to be
backported to stable trees and that has led to a more general discussion
about the current state of pfn walkers wrt. uninitialized pmem struct
pages. We haven't concluded any specific solution for that except for a
general sentiment that pfn_to_online_page should be able to catch those.
I might have missed any follow ups on that but I do not think we have
landed on any actual solution in the end. Have I just missed any followups?
Is anybody working on that?
Also is there any reference explaining what those struct pages are and
why we cannot initialize them? I am sorry if this has been explained to
me but I really cannot find that in my notes anywhere. Most pmem pages
should be initialized via memmap_init_zone_device, right?
I am asking mostly because we are starting to see these issues in
production and while the only visible problem so far is a crash when
reading sysfs (removable file) I am worried we are just lucky no other
pfn walker stumble over this.
[1] http://lkml.kernel.org/r/CAPcyv4jpdaNvJ67SkjyUJLBnBnXXQv686BiVW042g03FUmWLXw@mail.gmail.com
--
Michal Hocko
SUSE Labs
next reply other threads:[~2021-01-04 10:03 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-04 10:03 Michal Hocko [this message]
2021-01-04 10:45 ` David Hildenbrand
2021-01-04 14:26 ` Michal Hocko
2021-01-04 14:51 ` David Hildenbrand
2021-01-04 15:10 ` Michal Hocko
2021-01-04 15:15 ` David Hildenbrand
2021-01-04 15:33 ` Michal Hocko
2021-01-04 15:43 ` David Hildenbrand
2021-01-04 15:44 ` David Hildenbrand
2021-01-05 8:00 ` Michal Hocko
2021-01-05 8:16 ` Michal Hocko
2021-01-05 8:27 ` Dan Williams
2021-01-05 8:42 ` Michal Hocko
2021-01-05 8:57 ` Dan Williams
2021-01-05 9:05 ` Michal Hocko
2021-01-05 9:13 ` David Hildenbrand
2021-01-05 9:25 ` Michal Hocko
2021-01-05 9:27 ` David Hildenbrand
2021-01-04 15:59 ` Michal Hocko
2021-01-04 16:30 ` David Hildenbrand
2021-01-05 7:44 ` Michal Hocko
2021-01-05 9:56 ` David Hildenbrand
2021-01-05 5:33 ` Dan Williams
2021-01-05 7:40 ` Michal Hocko
2021-01-05 5:17 ` Dan Williams
2021-01-05 7:50 ` Michal Hocko
2021-01-05 9:16 ` David Hildenbrand
2021-01-05 9:25 ` David Hildenbrand
2021-01-05 9:33 ` Dan Williams
2021-01-05 9:37 ` David Hildenbrand
2021-01-05 9:56 ` Dan Williams
2021-01-05 9:58 ` David Hildenbrand
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