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Naoya Horiguchi 161df60e9e mm, hwpoison, hugetlb: support saving mechanism of raw error pages
When handling memory error on a hugetlb page, the error handler tries to
dissolve and turn it into 4kB pages.  If it's successfully dissolved,
PageHWPoison flag is moved to the raw error page, so that's all right. 
However, dissolve sometimes fails, then the error page is left as
hwpoisoned hugepage.  It's useful if we can retry to dissolve it to save
healthy pages, but that's not possible now because the information about
where the raw error pages is lost.

Use the private field of a few tail pages to keep that information.  The
code path of shrinking hugepage pool uses this info to try delayed
dissolve.  In order to remember multiple errors in a hugepage, a
singly-linked list originated from SUBPAGE_INDEX_HWPOISON-th tail page is
constructed.  Only simple operations (adding an entry or clearing all) are
required and the list is assumed not to be very long, so this simple data
structure should be enough.

If we failed to save raw error info, the hwpoison hugepage has errors on
unknown subpage, then this new saving mechanism does not work any more, so
disable saving new raw error info and freeing hwpoison hugepages.

Link: https://lkml.kernel.org/r/20220714042420.1847125-4-naoya.horiguchi@linux.dev
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08 18:06:44 -07:00
arch mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry 2022-08-08 18:06:43 -07:00
block for-5.20/block-2022-08-04 2022-08-04 20:00:14 -07:00
certs certs: make system keyring depend on x509 parser 2022-07-24 12:53:55 -07:00
crypto tpmdd updates for Linux v5.20 2022-08-06 09:43:02 -07:00
Documentation mm: hugetlb_vmemmap: move code comments to vmemmap_dedup.rst 2022-08-08 18:06:43 -07:00
drivers LED updates for 5.20: new driver for bcm63138, is31fl319x updates, 2022-08-08 11:36:21 -07:00
fs mm: hugetlb_vmemmap: introduce the name HVO 2022-08-08 18:06:42 -07:00
include mm, hwpoison, hugetlb: support saving mechanism of raw error pages 2022-08-08 18:06:44 -07:00
init Updates to various subsystems which I help look after. lib, ocfs2, 2022-08-07 10:03:24 -07:00
io_uring iov_iter work, part 1 - isolated cleanups and optimizations. 2022-08-03 13:50:22 -07:00
ipc Updates to various subsystems which I help look after. lib, ocfs2, 2022-08-07 10:03:24 -07:00
kernel Updates to various subsystems which I help look after. lib, ocfs2, 2022-08-07 10:03:24 -07:00
lib Bitmap patches for v6.0-rc1 2022-08-07 17:52:35 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm, hwpoison, hugetlb: support saving mechanism of raw error pages 2022-08-08 18:06:44 -07:00
net 9p-for-5.20 2022-08-06 14:48:54 -07:00
samples Tracing updates for 5.20 / 6.0 2022-08-05 09:41:12 -07:00
scripts Coccinelle semantic patch changes 2022-08-08 09:42:04 -07:00
security linux-kselftest-kunit-5.20-rc1 2022-08-02 19:34:45 -07:00
sound sound updates for 6.0-rc1 2022-08-06 10:19:51 -07:00
tools Bitmap patches for v6.0-rc1 2022-08-07 17:52:35 -07:00
usr Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
virt Merge remote-tracking branch 'kvm/next' into kvm-next-5.20 2022-08-01 03:21:00 -04:00
.clang-format clang-format: Fix space after for_each macros 2022-05-20 19:27:16 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: split the second line of *.mod into *.usyms 2022-05-08 03:16:59 +09:00
.mailmap Updates to various subsystems which I help look after. lib, ocfs2, 2022-08-07 10:03:24 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS drm for 5.20/6.0 2022-08-03 19:52:08 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS TTY / Serial driver changes for 6.0-rc1 2022-08-08 11:31:40 -07:00
Makefile linux-kselftest-next-5.20-rc1 2022-08-02 19:44:56 -07:00
README

Linux kernel
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