From: Yang Shi <shy828301@gmail.com>
To: Miaohe Lin <linmiaohe@huawei.com>
Cc: akpm@linux-foundation.org, nao.horiguchi@gmail.com,
xuyu@linux.alibaba.com, david@redhat.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] mm/huge_memory: don't unpoison huge_zero_folio
Date: Wed, 15 May 2024 09:58:32 -0600 [thread overview]
Message-ID: <CAHbLzkrO9-yWRFrWoE0idWwMffkBWNSku6iO2vdPLCpWAY7wQg@mail.gmail.com> (raw)
In-Reply-To: <20240515023607.870022-1-linmiaohe@huawei.com>
On Tue, May 14, 2024 at 8:39 PM Miaohe Lin <linmiaohe@huawei.com> wrote:
>
> When I did memory failure tests recently, below panic occurs:
>
> kernel BUG at include/linux/mm.h:1135!
> invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
> CPU: 9 PID: 137 Comm: kswapd1 Not tainted 6.9.0-rc4-00491-gd5ce28f156fe-dirty #14
> RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0
> RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246
> RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8
> RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0
> RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492
> R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000
> R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00
> FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0
> Call Trace:
> <TASK>
> do_shrink_slab+0x14f/0x6a0
> shrink_slab+0xca/0x8c0
> shrink_node+0x2d0/0x7d0
> balance_pgdat+0x33a/0x720
> kswapd+0x1f3/0x410
> kthread+0xd5/0x100
> ret_from_fork+0x2f/0x50
> ret_from_fork_asm+0x1a/0x30
> </TASK>
> Modules linked in: mce_inject hwpoison_inject
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0
> RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246
> RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8
> RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0
> RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492
> R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000
> R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00
> FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0
>
> The root cause is that HWPoison flag will be set for huge_zero_folio
> without increasing the folio refcnt. But then unpoison_memory() will
> decrease the folio refcnt unexpectly as it appears like a successfully
> hwpoisoned folio leading to VM_BUG_ON_PAGE(page_ref_count(page) == 0)
> when releasing huge_zero_folio.
>
> Skip unpoisoning huge_zero_folio in unpoison_memory() to fix this issue.
> We're not prepared to unpoison huge_zero_folio yet.
>
> Fixes: 478d134e9506 ("mm/huge_memory: do not overkill when splitting huge_zero_page")
> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
> Cc: <stable@vger.kernel.org>
Reviewed-by: Yang Shi <shy828301@gmail.com>
> ---
> v2:
> Change to simply check for the huge zero page. Thanks.
> ---
> mm/memory-failure.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 16ada4fb02b7..68bc8d7ff53d 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -2558,6 +2558,12 @@ int unpoison_memory(unsigned long pfn)
> goto unlock_mutex;
> }
>
> + if (is_huge_zero_folio(folio)) {
> + unpoison_pr_info("Unpoison: huge zero page is not supported %#lx\n",
> + pfn, &unpoison_rs);
> + goto unlock_mutex;
> + }
> +
> if (folio_test_slab(folio) || folio_test_pgtable(folio) ||
> folio_test_reserved(folio) || folio_test_offline(folio))
> goto unlock_mutex;
> --
> 2.33.0
>
prev parent reply other threads:[~2024-05-15 15:58 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-15 2:36 [PATCH v2] mm/huge_memory: don't unpoison huge_zero_folio Miaohe Lin
2024-05-15 15:55 ` David Hildenbrand
2024-05-16 8:26 ` Oscar Salvador
2024-05-16 8:45 ` Miaohe Lin
2024-05-16 9:07 ` Oscar Salvador
2024-05-15 15:58 ` Yang Shi [this message]
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 \
--in-reply-to=CAHbLzkrO9-yWRFrWoE0idWwMffkBWNSku6iO2vdPLCpWAY7wQg@mail.gmail.com \
--to=shy828301@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=david@redhat.com \
--cc=linmiaohe@huawei.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=nao.horiguchi@gmail.com \
--cc=xuyu@linux.alibaba.com \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).