Hi,
following up on previous fix-ups an refactors, this patchset simplifies
the get page interface and removes the MF_COUNT_INCREASED trick we have
for soft offline.
Please, note that this patchset is on top of [1] and [2].
This patchset does three things:
1) Drops MF_COUNT_INCREASED trick
2) Refactors get page interface
3) Places a common entry for grabbin a page from both hard offline
and soft offline guarded by zone_pcp_{disable/enable}, so we do not
have to drain pcplists by ourself and retry again.
Note that the MF_COUNT_INCREASED trick was left because if get_hwpoison_page
races with put_page (e.g:)
CPU0 CPU1
put_page (refcount decremented to 0)
__put_single_page
free_unref_page
free_unref_page_prepare
free_pcp_prepare
free_pages_prepare soft_offline_page
:page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP get_any_page
get_hwpoison_page
free_unref_page_commit
free_one_page
__free_one_page (place it in buddy)
get_hwpoison_page sees that page has a refcount of 0, but since it was not placed
in buddy yet we cannot really handle it.
We now have a sort of maximum passes in get_any_page, so in case we race
with either an allocation or a put_page, we retry again.
After an off-list discussion with Naoya, he agreed to proceed.
[1] https://patchwork.kernel.org/project/linux-mm/list/?series=364009
[2] https://patchwork.kernel.org/project/linux-mm/list/?series=381903
Naoya Horiguchi (3):
mm,madvise: call soft_offline_page() without MF_COUNT_INCREASED
mm,hwpoison: remove MF_COUNT_INCREASED
mm,hwpoison: remove flag argument from soft offline functions
Oscar Salvador (4):
mm,hwpoison: Refactor get_any_page
mm,hwpoison: Drop pfn parameter
mm,hwpoison: Disable pcplists before grabbing a refcount
mm,hwpoison: Remove drain_all_pages from shake_page
drivers/base/memory.c | 2 +-
include/linux/mm.h | 9 +--
mm/madvise.c | 19 +++--
mm/memory-failure.c | 168 +++++++++++++++++-------------------------
4 files changed, 85 insertions(+), 113 deletions(-)
--
2.26.2
