* [PATCH v2] mm/huge_memory: don't unpoison huge_zero_folio
@ 2024-05-15 2:36 Miaohe Lin
2024-05-15 15:55 ` David Hildenbrand
2024-05-15 15:58 ` Yang Shi
0 siblings, 2 replies; 6+ messages in thread
From: Miaohe Lin @ 2024-05-15 2:36 UTC (permalink / raw)
To: akpm
Cc: shy828301, nao.horiguchi, xuyu, david, linmiaohe, linux-mm, linux-kernel
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>
---
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
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] mm/huge_memory: don't unpoison huge_zero_folio
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
2024-05-15 15:58 ` Yang Shi
1 sibling, 1 reply; 6+ messages in thread
From: David Hildenbrand @ 2024-05-15 15:55 UTC (permalink / raw)
To: Miaohe Lin, akpm; +Cc: shy828301, nao.horiguchi, xuyu, linux-mm, linux-kernel
On 15.05.24 04:36, Miaohe Lin 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>
> ---
> 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;
Acked-by: David Hildenbrand <david@redhat.com>
--
Cheers,
David / dhildenb
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] mm/huge_memory: don't unpoison huge_zero_folio
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
@ 2024-05-15 15:58 ` Yang Shi
1 sibling, 0 replies; 6+ messages in thread
From: Yang Shi @ 2024-05-15 15:58 UTC (permalink / raw)
To: Miaohe Lin; +Cc: akpm, nao.horiguchi, xuyu, david, linux-mm, linux-kernel
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
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] mm/huge_memory: don't unpoison huge_zero_folio
2024-05-15 15:55 ` David Hildenbrand
@ 2024-05-16 8:26 ` Oscar Salvador
2024-05-16 8:45 ` Miaohe Lin
0 siblings, 1 reply; 6+ messages in thread
From: Oscar Salvador @ 2024-05-16 8:26 UTC (permalink / raw)
To: David Hildenbrand
Cc: Miaohe Lin, akpm, shy828301, nao.horiguchi, xuyu, linux-mm, linux-kernel
On Wed, May 15, 2024 at 05:55:39PM +0200, David Hildenbrand wrote:
> > + if (is_huge_zero_folio(folio)) {
> > + unpoison_pr_info("Unpoison: huge zero page is not supported %#lx\n",
> > + pfn, &unpoison_rs);
> > + goto unlock_mutex;
> > + }
> > +
Sorry for spamming your reply David, but for some unknown reason I am not able
to find the original patch in my mailbox, in none of the two accountes I am
subscribed, so I guess I will have to reply here.
Just two things
1) We do not care if someone grabs a refcount for huge_zero_folio,
because since it is not supported anyway the outcome will not change.
Also, AFAIK, there is no chance we can unpoison that folio.
Therefore, I would just lift the check two blocks and place it right after
the hw_memory_failure check.
2) The whole thing is unsupported, but you will return -EBUSY while you
should be returning -EOPNOTSUPP AFAICS.
with that you can add:
Reviewed-by: Oscar Salvador <osalvador@suse.de>
--
Oscar Salvador
SUSE Labs
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] mm/huge_memory: don't unpoison huge_zero_folio
2024-05-16 8:26 ` Oscar Salvador
@ 2024-05-16 8:45 ` Miaohe Lin
2024-05-16 9:07 ` Oscar Salvador
0 siblings, 1 reply; 6+ messages in thread
From: Miaohe Lin @ 2024-05-16 8:45 UTC (permalink / raw)
To: Oscar Salvador, David Hildenbrand
Cc: akpm, shy828301, nao.horiguchi, xuyu, linux-mm, linux-kernel
On 2024/5/16 16:26, Oscar Salvador wrote:
> On Wed, May 15, 2024 at 05:55:39PM +0200, David Hildenbrand wrote:
>>> + if (is_huge_zero_folio(folio)) {
>>> + unpoison_pr_info("Unpoison: huge zero page is not supported %#lx\n",
>>> + pfn, &unpoison_rs);
>>> + goto unlock_mutex;
>>> + }
>>> +
>
> Sorry for spamming your reply David, but for some unknown reason I am not able
> to find the original patch in my mailbox, in none of the two accountes I am
> subscribed, so I guess I will have to reply here.
>
> Just two things
>
> 1) We do not care if someone grabs a refcount for huge_zero_folio,
> because since it is not supported anyway the outcome will not change.
> Also, AFAIK, there is no chance we can unpoison that folio.
> Therefore, I would just lift the check two blocks and place it right after
> the hw_memory_failure check.
>
> 2) The whole thing is unsupported, but you will return -EBUSY while you
> should be returning -EOPNOTSUPP AFAICS.
>
Thanks for your comment. Do you mean something like below?
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 16ada4fb02b7..a9fe9eda593f 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -2546,6 +2546,13 @@ 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);
+ ret = -EOPNOTSUPP;
+ goto unlock_mutex;
+ }
+
if (!PageHWPoison(p)) {
unpoison_pr_info("Unpoison: Page was already unpoisoned %#lx\n",
pfn, &unpoison_rs);
Thanks.
.
> with that you can add:
>
> Reviewed-by: Oscar Salvador <osalvador@suse.de>
>
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] mm/huge_memory: don't unpoison huge_zero_folio
2024-05-16 8:45 ` Miaohe Lin
@ 2024-05-16 9:07 ` Oscar Salvador
0 siblings, 0 replies; 6+ messages in thread
From: Oscar Salvador @ 2024-05-16 9:07 UTC (permalink / raw)
To: Miaohe Lin
Cc: David Hildenbrand, akpm, shy828301, nao.horiguchi, xuyu,
linux-mm, linux-kernel
On Thu, May 16, 2024 at 04:45:22PM +0800, Miaohe Lin wrote:
> Thanks for your comment. Do you mean something like below?
>
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 16ada4fb02b7..a9fe9eda593f 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -2546,6 +2546,13 @@ 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);
> + ret = -EOPNOTSUPP;
> + goto unlock_mutex;
> + }
> +
> if (!PageHWPoison(p)) {
> unpoison_pr_info("Unpoison: Page was already unpoisoned %#lx\n",
> pfn, &unpoison_rs);
Yes, something like that makes much more sense to me.
Thanks
--
Oscar Salvador
SUSE Labs
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2024-05-16 9:07 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
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 is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox