From: Oscar Salvador <email@example.com> To: firstname.lastname@example.org Cc: email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com, Oscar Salvador <firstname.lastname@example.org> Subject: [PATCH v4 00/15] Hwpoison soft-offline rework Date: Thu, 16 Jul 2020 14:37:54 +0200 [thread overview] Message-ID: <email@example.com> (raw) Hi all, this is a follow-up version on . That version had some flaws wrt. handling hugetlb pages, so this version fixes it. I checked that the case reported by Qian seems to work fine now. Cover letter: This patchset was initially based on Naoya's hwpoison rework , so thanks to him for the initial work. I would also like to think Naoya for testing the patchset off-line, and report any issues he found, that was quite helpful. This patchset aims to fix some issues laying in soft-offline handling, but it also takes the chance and takes some further steps to perform cleanups and some refactoring as well. - Motivation: A customer and I were facing an issue were processes were killed after having soft-offlined some of their pages. This should not happen when soft-offlining, as it is meant to be non-disruptive. I was able to reproduce the issue when I stressed the memory + soft offlining pages in the meantime. After debugging the issue, I saw that the problem was that pages were returned back to user-space after having offlined them properly. So, when those pages were faulted in, the fault handler returned VM_FAULT_POISON all the way down to the arch handler, and it simply killed the process. After a further anaylsis, it became clear that the problem was that when kcompactd kicked in to migrate pages over, compaction_alloc callback was handing poisoned pages to the migrate routine. All this could happen because isolate_freepages_block and fast_isolate_freepages just check for the page to be PageBuddy, and since 1) poisoned pages can be part of a higher order page and 2) poisoned pages are also Page Buddy, they can sneak in easily. I also saw some other problems with sawap pages, but I suspected it to be the same sort of problem, so I did not follow that trace. The above refers to soft-offline. But I also saw problems with hard-offline, specially hugetlb corruption, and some other weird stuff. (I could paste the logs) The full explanation refering to the soft-offline case can be found at . - Approach: The taken approach is to contain those pages and never let them hit neither pcplists nor buddy freelists. Only when they are completely out of reach, we flag them as poisoned. A full explanation of this can be found in patch#11 and patch#12 - Outcome: With this patchset, I no longer see the issues with soft-offline.  https://firstname.lastname@example.org/  https://lore.kernel.org/linux-mm/20190826104144.GA7849@linux/T/#u Naoya Horiguchi (6): 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 Oscar Salvador (9): 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 mm,hwpoison: introduce MF_MSG_UNSPLIT_THP drivers/base/memory.c | 2 +- include/linux/mm.h | 12 +- include/linux/page-flags.h | 6 +- include/ras/ras_event.h | 3 + mm/hugetlb.c | 60 +++++++- mm/hwpoison-inject.c | 18 +-- mm/madvise.c | 37 ++--- mm/memory-failure.c | 307 +++++++++++++++---------------------- mm/migrate.c | 11 +- mm/page_alloc.c | 70 +++++++-- 10 files changed, 270 insertions(+), 256 deletions(-) -- 2.26.2
next reply other threads:[~2020-07-16 12:38 UTC|newest] Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-07-16 12:37 Oscar Salvador [this message] 2020-07-16 12:37 ` [PATCH v4 01/15] mm,hwpoison: cleanup unused PageHuge() check Oscar Salvador 2020-07-16 12:37 ` [PATCH v4 02/15] mm, hwpoison: remove recalculating hpage Oscar Salvador 2020-07-16 12:37 ` [PATCH v4 03/15] mm,madvise: call soft_offline_page() without MF_COUNT_INCREASED Oscar Salvador 2020-07-16 23:15 ` Mike Kravetz 2020-07-16 12:37 ` [PATCH v4 04/15] mm,madvise: Refactor madvise_inject_error Oscar Salvador 2020-07-16 12:37 ` [PATCH v4 05/15] mm,hwpoison-inject: don't pin for hwpoison_filter Oscar Salvador 2020-07-16 12:38 ` [PATCH v4 06/15] mm,hwpoison: Un-export get_hwpoison_page and make it static Oscar Salvador 2020-07-16 12:38 ` [PATCH v4 07/15] mm,hwpoison: Kill put_hwpoison_page Oscar Salvador 2020-07-16 12:38 ` [PATCH v4 08/15] mm,hwpoison: remove MF_COUNT_INCREASED Oscar Salvador 2020-07-16 12:38 ` [PATCH v4 09/15] mm,hwpoison: remove flag argument from soft offline functions Oscar Salvador 2020-07-16 12:38 ` [PATCH v4 10/15] mm,hwpoison: Unify THP handling for hard and soft offline Oscar Salvador 2020-07-16 12:38 ` [PATCH v4 11/15] mm,hwpoison: Rework soft offline for free pages Oscar Salvador 2020-07-16 12:38 ` [PATCH v4 12/15] mm,hwpoison: Rework soft offline for in-use pages Oscar Salvador 2020-07-17 6:55 ` HORIGUCHI NAOYA(堀口 直也) [not found] ` <f7387d64d0024d15a1bc821a8e19b8f0@DB7PR04MB5180.eurprd04.prod.outlook.com> 2020-07-20 8:27 ` osalvador 2020-07-22 8:08 ` osalvador 2020-07-23 10:19 ` Oscar Salvador 2020-07-16 12:38 ` [PATCH v4 13/15] mm,hwpoison: Refactor soft_offline_huge_page and __soft_offline_page Oscar Salvador 2020-07-16 12:38 ` [PATCH v4 14/15] mm,hwpoison: Return 0 if the page is already poisoned in soft-offline Oscar Salvador 2020-07-16 12:38 ` [PATCH v4 15/15] mm,hwpoison: introduce MF_MSG_UNSPLIT_THP Oscar Salvador 2020-07-16 12:38 ` [PATCH] x86/speculation: Add basic IBPB (Indirect Branch Prediction Barrier) support Oscar Salvador 2020-07-16 12:43 ` osalvador 2020-07-17 14:49 ` [PATCH v4 00/15] Hwpoison soft-offline rework Qian Cai
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --email@example.com \ --firstname.lastname@example.org \ --email@example.com \ --firstname.lastname@example.org \ --email@example.com \ --firstname.lastname@example.org \ --email@example.com \ --firstname.lastname@example.org \ --email@example.com \ --firstname.lastname@example.org \ --subject='Re: [PATCH v4 00/15] Hwpoison soft-offline rework' \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.