From: Peter Xu <peterx@redhat.com>
To: Yang Shi <shy828301@gmail.com>
Cc: "HORIGUCHI NAOYA(堀口 直也)" <naoya.horiguchi@nec.com>,
"Hugh Dickins" <hughd@google.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
"Matthew Wilcox" <willy@infradead.org>,
"Oscar Salvador" <osalvador@suse.de>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Linux MM" <linux-mm@kvack.org>,
"Linux FS-devel Mailing List" <linux-fsdevel@vger.kernel.org>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>
Subject: Re: [RFC v3 PATCH 0/5] Solve silent data loss caused by poisoned page cache (shmem/tmpfs)
Date: Wed, 13 Oct 2021 11:24:31 +0800 [thread overview]
Message-ID: <YWZRb9Z4YIv95ieh@t490s> (raw)
In-Reply-To: <CAHbLzkoz6Gm31Qz-u_ohR6NK2RRE5OdEkSq_3t9Cjwkqf1+a7w@mail.gmail.com>
On Tue, Oct 12, 2021 at 08:09:24PM -0700, Yang Shi wrote:
> On Tue, Oct 12, 2021 at 7:41 PM Peter Xu <peterx@redhat.com> wrote:
> >
> > On Thu, Sep 30, 2021 at 02:53:06PM -0700, Yang Shi wrote:
> > > Yang Shi (5):
> > > mm: hwpoison: remove the unnecessary THP check
> > > mm: filemap: check if THP has hwpoisoned subpage for PMD page fault
> > > mm: hwpoison: refactor refcount check handling
> > > mm: shmem: don't truncate page if memory failure happens
> > > mm: hwpoison: handle non-anonymous THP correctly
> >
> > Today I just noticed one more thing: unpoison path has (unpoison_memory):
> >
> > if (page_mapping(page)) {
> > unpoison_pr_info("Unpoison: the hwpoison page has non-NULL mapping %#lx\n",
> > pfn, &unpoison_rs);
> > return 0;
> > }
> >
> > I _think_ it was used to make sure we ignore page that was not successfully
> > poisoned/offlined before (for anonymous), so raising this question up on
> > whether we should make sure e.g. shmem hwpoisoned pages still can be unpoisoned
> > for debugging purposes.
>
> Yes, not only mapping, the refcount check is not right if page cache
> page is kept in page cache instead of being truncated after this
> series. But actually unpoison has been broken since commit
> 0ed950d1f28142ccd9a9453c60df87853530d778 ("mm,hwpoison: make
> get_hwpoison_page() call get_any_page()"). And Naoya said in the
> commit "unpoison_memory() is also unchanged because it's broken and
> need thorough fixes (will be done later)."
>
> I do have some fixes in my tree to unblock tests and fix unpoison for
> this series (just make it work for testing). Naoya may have some ideas
> in mind and it is just a debugging feature so I don't think it must be
> fixed in this series. It could be done later. I could add a TODO
> section in the cover letter to make this more clear.
I see, that sounds good enough to me. Thanks,
--
Peter Xu
next prev parent reply other threads:[~2021-10-13 3:25 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-30 21:53 [RFC v3 PATCH 0/5] Solve silent data loss caused by poisoned page cache (shmem/tmpfs) Yang Shi
2021-09-30 21:53 ` [v3 PATCH 1/5] mm: hwpoison: remove the unnecessary THP check Yang Shi
2021-10-06 2:35 ` Yang Shi
2021-10-06 4:00 ` Naoya Horiguchi
2021-10-06 17:56 ` Yang Shi
2021-09-30 21:53 ` [v3 PATCH 2/5] mm: filemap: check if THP has hwpoisoned subpage for PMD page fault Yang Shi
2021-10-01 7:23 ` Naoya Horiguchi
2021-10-01 21:07 ` Yang Shi
2021-10-04 14:06 ` Kirill A. Shutemov
2021-10-04 18:17 ` Yang Shi
2021-10-04 19:41 ` Kirill A. Shutemov
2021-10-04 20:13 ` Yang Shi
2021-10-06 19:54 ` Peter Xu
2021-10-06 23:41 ` Yang Shi
2021-10-07 16:14 ` Peter Xu
2021-10-07 18:28 ` Yang Shi
2021-10-08 9:35 ` Kirill A. Shutemov
2021-10-11 22:57 ` Peter Xu
2021-10-06 20:15 ` Peter Xu
2021-10-06 23:57 ` Yang Shi
2021-10-07 16:06 ` Peter Xu
2021-10-07 18:19 ` Yang Shi
2021-10-07 20:27 ` Yang Shi
2021-10-07 21:28 ` Yang Shi
2021-10-12 0:55 ` Peter Xu
2021-10-12 1:44 ` Peter Xu
2021-10-12 18:02 ` Yang Shi
2021-10-12 22:10 ` Peter Xu
2021-10-13 2:48 ` Yang Shi
2021-10-13 3:01 ` Peter Xu
2021-10-13 3:27 ` Yang Shi
2021-10-13 3:41 ` Peter Xu
2021-10-13 21:42 ` Yang Shi
2021-10-13 23:13 ` Peter Xu
2021-10-14 6:54 ` Naoya Horiguchi
2021-10-06 20:18 ` Peter Xu
2021-10-07 2:49 ` Yang Shi
2021-11-01 19:05 ` Naresh Kamboju
2021-11-01 19:26 ` Yang Shi
2021-09-30 21:53 ` [v3 PATCH 3/5] mm: hwpoison: refactor refcount check handling Yang Shi
2021-10-06 22:01 ` Peter Xu
2021-10-07 2:47 ` Yang Shi
2021-10-07 16:18 ` Peter Xu
2021-09-30 21:53 ` [v3 PATCH 4/5] mm: shmem: don't truncate page if memory failure happens Yang Shi
2021-10-01 7:05 ` Naoya Horiguchi
2021-10-01 21:08 ` Yang Shi
2021-10-12 1:57 ` Peter Xu
2021-10-12 19:17 ` Yang Shi
2021-10-12 22:26 ` Peter Xu
2021-10-13 3:00 ` Yang Shi
2021-10-13 3:06 ` Peter Xu
2021-10-13 3:29 ` Yang Shi
2021-09-30 21:53 ` [v3 PATCH 5/5] mm: hwpoison: handle non-anonymous THP correctly Yang Shi
2021-10-01 7:06 ` Naoya Horiguchi
2021-10-01 21:09 ` Yang Shi
2021-10-13 2:40 ` [RFC v3 PATCH 0/5] Solve silent data loss caused by poisoned page cache (shmem/tmpfs) Peter Xu
2021-10-13 3:09 ` Yang Shi
2021-10-13 3:24 ` Peter Xu [this message]
2021-10-14 6:54 ` Naoya Horiguchi
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