Messages in this thread |  | | From | Oscar Salvador <> | Subject | [PATCH 0/7] HWPoison: Refactor get page interface | Date | Thu, 19 Nov 2020 11:57:09 +0100 |
| |
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
|  |