From: Qian Cai <cai@lca.pw>
To: nao.horiguchi@gmail.com
Cc: linux-mm@kvack.org, mhocko@kernel.org, akpm@linux-foundation.org,
mike.kravetz@oracle.com, osalvador@suse.de, tony.luck@intel.com,
david@redhat.com, aneesh.kumar@linux.vnet.ibm.com,
zeil@yandex-team.ru, naoya.horiguchi@nec.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 00/16] HWPOISON: soft offline rework
Date: Mon, 3 Aug 2020 15:07:09 -0400 [thread overview]
Message-ID: <20200803190709.GB8894@lca.pw> (raw)
In-Reply-To: <20200731122112.11263-1-nao.horiguchi@gmail.com>
On Fri, Jul 31, 2020 at 12:20:56PM +0000, nao.horiguchi@gmail.com wrote:
> This patchset is the latest version of soft offline rework patchset
> targetted for v5.9.
>
> Main focus of this series is to stabilize soft offline. Historically soft
> offlined pages have suffered from racy conditions because PageHWPoison is
> used to a little too aggressively, which (directly or indirectly) invades
> other mm code which cares little about hwpoison. This results in unexpected
> behavior or kernel panic, which is very far from soft offline's "do not
> disturb userspace or other kernel component" policy.
>
> Main point of this change set is to contain target page "via buddy allocator",
> where we first free the target page as we do for normal pages, and remove
> from buddy only when we confirm that it reaches free list. There is surely
> race window of page allocation, but that's fine because someone really want
> that page and the page is still working, so soft offline can happily give up.
>
> v4 from Oscar tries to handle the race around reallocation, but that part
> seems still work in progress, so I decide to separate it for changes into
> v5.9. Thank you for your contribution, Oscar.
>
> The issue reported by Qian Cai is fixed by patch 16/16.
>
> This patchset is based on v5.8-rc7-mmotm-2020-07-27-18-18, but I applied
> this series after reverting previous version.
> Maybe https://github.com/Naoya-Horiguchi/linux/commits/soft-offline-rework.v5
> shows what I did more precisely.
>
> Any other comment/suggestion/help would be appreciated.
There is another issue with this patchset (with and without the patch [1]).
[1] https://lore.kernel.org/lkml/20200803133657.GA13307@hori.linux.bs1.fc.nec.co.jp/
Arm64 using 512M-size hugepages starts to fail allocations prematurely.
# ./random 1
- start: migrate_huge_offline
- use NUMA nodes 0,1.
- mmap and free 2147483648 bytes hugepages on node 0
- mmap and free 2147483648 bytes hugepages on node 1
madvise: Cannot allocate memory
[ 284.388061][ T3706] soft offline: 0x956000: hugepage isolation failed: 0, page count 2, type 17ffff80001000e (referenced|uptodate|dirty|head)
[ 284.400777][ T3706] Soft offlining pfn 0x8e000 at process virtual address 0xffff80000000
[ 284.893412][ T3706] Soft offlining pfn 0x8a000 at process virtual address 0xffff60000000
[ 284.901539][ T3706] soft offline: 0x8a000: hugepage isolation failed: 0, page count 2, type 7ffff80001000e (referenced|uptodate|dirty|head)
[ 284.914129][ T3706] Soft offlining pfn 0x8c000 at process virtual address 0xffff80000000
[ 285.433497][ T3706] Soft offlining pfn 0x88000 at process virtual address 0xffff60000000
[ 285.720377][ T3706] Soft offlining pfn 0x8a000 at process virtual address 0xffff80000000
[ 286.281620][ T3706] Soft offlining pfn 0xa000 at process virtual address 0xffff60000000
[ 286.290065][ T3706] soft offline: 0xa000: hugepage migration failed -12, type 7ffff80001000e (referenced|uptodate|dirty|head)
Reverting this patchset and its dependency patchset [2] (reverting the
dependency alone did not help) fixed it,
# ./random 1
- start: migrate_huge_offline
- use NUMA nodes 0,1.
- mmap and free 2147483648 bytes hugepages on node 0
- mmap and free 2147483648 bytes hugepages on node 1
- pass: mmap_offline_node_huge
[2] https://lore.kernel.org/linux-mm/1594622517-20681-1-git-send-email-iamjoonsoo.kim@lge.com/
>
> Thanks,
> Naoya Horiguchi
> ---
> Previous versions:
> v1: https://lore.kernel.org/linux-mm/1541746035-13408-1-git-send-email-n-horiguchi@ah.jp.nec.com/
> v2: https://lore.kernel.org/linux-mm/20191017142123.24245-1-osalvador@suse.de/
> v3: https://lore.kernel.org/linux-mm/20200624150137.7052-1-nao.horiguchi@gmail.com/
> v4: https://lore.kernel.org/linux-mm/20200716123810.25292-1-osalvador@suse.de/
> ---
> Summary:
>
> Naoya Horiguchi (8):
> mm,hwpoison: cleanup unused PageHuge() check
> mm, hwpoison: remove recalculating hpage
> mm,madvise: call soft_offline_page() without MF_COUNT_INCREASED
> mm,hwpoison-inject: don't pin for hwpoison_filter
> mm,hwpoison: remove MF_COUNT_INCREASED
> mm,hwpoison: remove flag argument from soft offline functions
> mm,hwpoison: introduce MF_MSG_UNSPLIT_THP
> mm,hwpoison: double-check page count in __get_any_page()
>
> Oscar Salvador (8):
> mm,madvise: Refactor madvise_inject_error
> mm,hwpoison: Un-export get_hwpoison_page and make it static
> mm,hwpoison: Kill put_hwpoison_page
> mm,hwpoison: Unify THP handling for hard and soft offline
> mm,hwpoison: Rework soft offline for free pages
> mm,hwpoison: Rework soft offline for in-use pages
> mm,hwpoison: Refactor soft_offline_huge_page and __soft_offline_page
> mm,hwpoison: Return 0 if the page is already poisoned in soft-offline
>
> drivers/base/memory.c | 2 +-
> include/linux/mm.h | 12 +-
> include/linux/page-flags.h | 6 +-
> include/ras/ras_event.h | 3 +
> mm/hwpoison-inject.c | 18 +--
> mm/madvise.c | 39 +++---
> mm/memory-failure.c | 334 ++++++++++++++++++++-------------------------
> mm/migrate.c | 11 +-
> mm/page_alloc.c | 60 ++++++--
> 9 files changed, 233 insertions(+), 252 deletions(-)
next prev parent reply other threads:[~2020-08-03 19:07 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-31 12:20 [PATCH v5 00/16] HWPOISON: soft offline rework nao.horiguchi
2020-07-31 12:20 ` [PATCH v5 01/16] mm,hwpoison: cleanup unused PageHuge() check nao.horiguchi
2020-07-31 12:20 ` [PATCH v5 02/16] mm, hwpoison: remove recalculating hpage nao.horiguchi
2020-07-31 12:20 ` [PATCH v5 03/16] mm,madvise: call soft_offline_page() without MF_COUNT_INCREASED nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 04/16] mm,madvise: Refactor madvise_inject_error nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 05/16] mm,hwpoison-inject: don't pin for hwpoison_filter nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 06/16] mm,hwpoison: Un-export get_hwpoison_page and make it static nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 07/16] mm,hwpoison: Kill put_hwpoison_page nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 08/16] mm,hwpoison: remove MF_COUNT_INCREASED nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 09/16] mm,hwpoison: remove flag argument from soft offline functions nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 10/16] mm,hwpoison: Unify THP handling for hard and soft offline nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 11/16] mm,hwpoison: Rework soft offline for free pages nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 12/16] mm,hwpoison: Rework soft offline for in-use pages nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 13/16] mm,hwpoison: Refactor soft_offline_huge_page and __soft_offline_page nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 14/16] mm,hwpoison: Return 0 if the page is already poisoned in soft-offline nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 15/16] mm,hwpoison: introduce MF_MSG_UNSPLIT_THP nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 16/16] mm,hwpoison: double-check page count in __get_any_page() nao.horiguchi
2020-08-03 12:39 ` [PATCH v5 00/16] HWPOISON: soft offline rework Qian Cai
2020-08-03 13:36 ` HORIGUCHI NAOYA(堀口 直也)
2020-08-03 15:19 ` Qian Cai
2020-08-05 20:43 ` HORIGUCHI NAOYA(堀口 直也)
2020-08-03 19:07 ` Qian Cai [this message]
2020-08-04 1:16 ` HORIGUCHI NAOYA(堀口 直也)
2020-08-04 1:49 ` Qian Cai
2020-08-04 8:13 ` osalvador
2020-08-05 20:44 ` HORIGUCHI NAOYA(堀口 直也)
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