From: David Hildenbrand <david@redhat.com>
To: linux-kernel@vger.kernel.org, Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org,
linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-s390@vger.kernel.org, linux-sh@vger.kernel.org,
x86@kernel.org, Oscar Salvador <osalvador@suse.de>,
Michal Hocko <mhocko@suse.com>,
Pavel Tatashin <pasha.tatashin@soleen.com>,
Dan Williams <dan.j.williams@intel.com>,
"Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Subject: Re: [PATCH v6 04/10] mm/memory_hotplug: Don't access uninitialized memmaps in shrink_zone_span()
Date: Mon, 14 Oct 2019 11:32:13 +0200 [thread overview]
Message-ID: <5a4573de-bd8a-6cd3-55d0-86d503a236fd@redhat.com> (raw)
In-Reply-To: <20191006085646.5768-5-david@redhat.com>
On 06.10.19 10:56, David Hildenbrand wrote:
> Let's limit shrinking to !ZONE_DEVICE so we can fix the current code. We
> should never try to touch the memmap of offline sections where we could
> have uninitialized memmaps and could trigger BUGs when calling
> page_to_nid() on poisoned pages.
>
> There is no reliable way to distinguish an uninitialized memmap from an
> initialized memmap that belongs to ZONE_DEVICE, as we don't have
> anything like SECTION_IS_ONLINE we can use similar to
> pfn_to_online_section() for !ZONE_DEVICE memory. E.g.,
> set_zone_contiguous() similarly relies on pfn_to_online_section() and
> will therefore never set a ZONE_DEVICE zone consecutive. Stopping to
> shrink the ZONE_DEVICE therefore results in no observable changes,
> besides /proc/zoneinfo indicating different boundaries - something we
> can totally live with.
>
> Before commit d0dc12e86b31 ("mm/memory_hotplug: optimize memory
> hotplug"), the memmap was initialized with 0 and the node with the
> right value. So the zone might be wrong but not garbage. After that
> commit, both the zone and the node will be garbage when touching
> uninitialized memmaps.
>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Oscar Salvador <osalvador@suse.de>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Fixes: d0dc12e86b31 ("mm/memory_hotplug: optimize memory hotplug")
@Andrew, can you convert that to
Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded
memory to zones until online") # visible after d0dc12e86b319
and add
Cc: stable@vger.kernel.org # v4.13+
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2019-10-14 9:32 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-06 8:56 [PATCH v6 00/10] mm/memory_hotplug: Shrink zones before removing memory David Hildenbrand
2019-10-06 8:56 ` [PATCH v6 01/10] mm/memunmap: Don't access uninitialized memmap in memunmap_pages() David Hildenbrand
2019-10-06 19:58 ` Damian Tometzki
2019-10-06 20:13 ` David Hildenbrand
2019-10-14 9:05 ` David Hildenbrand
2019-10-06 8:56 ` [PATCH v6 02/10] mm/memmap_init: Update variable name in memmap_init_zone David Hildenbrand
2019-10-06 8:56 ` [PATCH v6 03/10] mm/memory_hotplug: Don't access uninitialized memmaps in shrink_pgdat_span() David Hildenbrand
2019-10-14 9:31 ` David Hildenbrand
2019-10-06 8:56 ` [PATCH v6 04/10] mm/memory_hotplug: Don't access uninitialized memmaps in shrink_zone_span() David Hildenbrand
2019-10-14 9:32 ` David Hildenbrand [this message]
2019-10-14 19:17 ` Andrew Morton
2019-11-19 14:16 ` David Hildenbrand
2019-11-19 20:44 ` Andrew Morton
2019-10-06 8:56 ` [PATCH v6 05/10] mm/memory_hotplug: Shrink zones when offlining memory David Hildenbrand
2019-10-14 9:39 ` David Hildenbrand
2019-10-14 19:16 ` Andrew Morton
2019-10-27 22:45 ` David Hildenbrand
2019-11-30 23:21 ` Andrew Morton
2019-11-30 23:43 ` David Hildenbrand
2019-12-18 17:08 ` David Hildenbrand
2019-12-18 20:16 ` Andrew Morton
2019-12-03 15:10 ` Oscar Salvador
2019-12-03 15:27 ` David Hildenbrand
2019-10-06 8:56 ` [PATCH v6 06/10] mm/memory_hotplug: Poison memmap in remove_pfn_range_from_zone() David Hildenbrand
2019-10-16 14:01 ` David Hildenbrand
2020-02-04 8:59 ` Oscar Salvador
2019-10-06 8:56 ` [PATCH v6 07/10] mm/memory_hotplug: We always have a zone in find_(smallest|biggest)_section_pfn David Hildenbrand
2020-02-04 9:06 ` Oscar Salvador
2020-02-05 8:57 ` Wei Yang
2020-02-05 8:59 ` David Hildenbrand
2020-02-05 9:26 ` Wei Yang
2019-10-06 8:56 ` [PATCH v6 08/10] mm/memory_hotplug: Don't check for "all holes" in shrink_zone_span() David Hildenbrand
2020-02-04 9:13 ` Oscar Salvador
2020-02-04 9:20 ` David Hildenbrand
2020-02-04 14:25 ` Baoquan He
2020-02-04 14:42 ` David Hildenbrand
2020-02-05 12:43 ` Baoquan He
2020-02-05 13:20 ` David Hildenbrand
2020-02-05 13:34 ` Baoquan He
2020-02-05 13:38 ` David Hildenbrand
2020-02-05 14:12 ` Baoquan He
2020-02-05 14:16 ` David Hildenbrand
2020-02-05 14:26 ` Baoquan He
2020-02-05 9:59 ` Wei Yang
2020-02-05 14:48 ` Baoquan He
2020-02-05 22:56 ` Wei Yang
2020-02-05 23:08 ` Baoquan He
2020-02-05 23:26 ` Wei Yang
2020-02-05 23:30 ` Baoquan He
2020-02-05 23:34 ` Wei Yang
2020-02-05 14:54 ` David Laight
2020-02-05 14:55 ` David Hildenbrand
2019-10-06 8:56 ` [PATCH v6 09/10] mm/memory_hotplug: Drop local variables " David Hildenbrand
2020-02-04 9:26 ` Oscar Salvador
2020-02-04 9:29 ` David Hildenbrand
2020-02-05 10:07 ` Wei Yang
2019-10-06 8:56 ` [PATCH v6 10/10] mm/memory_hotplug: Cleanup __remove_pages() David Hildenbrand
2020-02-04 9:46 ` Oscar Salvador
2020-02-04 12:41 ` David Hildenbrand
2020-02-04 13:13 ` Segher Boessenkool
2020-02-04 13:38 ` David Hildenbrand
2020-02-05 12:51 ` Segher Boessenkool
2020-02-05 13:17 ` David Hildenbrand
2020-02-05 13:18 ` David Hildenbrand
2020-02-05 13:23 ` David Hildenbrand
2020-02-05 11:48 ` Wei Yang
2019-12-02 9:09 ` [PATCH v6 00/10] mm/memory_hotplug: Shrink zones before removing memory David Hildenbrand
2019-12-03 13:36 ` Oscar Salvador
2020-01-31 4:40 ` Andrew Morton
2020-01-31 9:18 ` David Hildenbrand
2020-01-31 10:03 ` Michal Hocko
2020-01-31 10:36 ` David Hildenbrand
2020-02-04 1:46 ` Andrew Morton
2020-02-04 8:45 ` David Hildenbrand
2020-02-04 9:51 ` Oscar Salvador
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