* [PATCH v3] mm/huge_memory: don't unpoison huge_zero_folio
@ 2024-05-16 12:26 Miaohe Lin
2024-05-17 7:02 ` Anshuman Khandual
0 siblings, 1 reply; 3+ messages in thread
From: Miaohe Lin @ 2024-05-16 12:26 UTC (permalink / raw)
To: akpm
Cc: shy828301, nao.horiguchi, xuyu, david, osalvador, 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>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
---
v3:
Move up is_huge_zero_folio() check and change return value to
-EOPNOTSUPP per Oscar.
Collect Reviewed-by and Acked-by tag. Thanks.
v2:
Change to simply check for the huge zero page per David. Thanks.
---
mm/memory-failure.c | 7 +++++++
1 file changed, 7 insertions(+)
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);
--
2.33.0
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v3] mm/huge_memory: don't unpoison huge_zero_folio
2024-05-16 12:26 [PATCH v3] mm/huge_memory: don't unpoison huge_zero_folio Miaohe Lin
@ 2024-05-17 7:02 ` Anshuman Khandual
2024-05-20 1:51 ` Miaohe Lin
0 siblings, 1 reply; 3+ messages in thread
From: Anshuman Khandual @ 2024-05-17 7:02 UTC (permalink / raw)
To: Miaohe Lin, akpm
Cc: shy828301, nao.horiguchi, xuyu, david, osalvador, linux-mm, linux-kernel
On 5/16/24 17:56, 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
Small nit, a typo in here ^^^^^ s/unexpectly/unexpectedly/.
> 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")
The target commit looks right.
> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
> Acked-by: David Hildenbrand <david@redhat.com>
> Reviewed-by: Yang Shi <shy828301@gmail.com>
> Reviewed-by: Oscar Salvador <osalvador@suse.de>
> Cc: <stable@vger.kernel.org>
> ---
> v3:
> Move up is_huge_zero_folio() check and change return value to
> -EOPNOTSUPP per Oscar.
> Collect Reviewed-by and Acked-by tag. Thanks.
> v2:
> Change to simply check for the huge zero page per David. Thanks.
> ---
> mm/memory-failure.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> 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);
This patch applies on latest linux-next but not on latest mainline as
is_huge_zero_folio() is absent there.
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v3] mm/huge_memory: don't unpoison huge_zero_folio
2024-05-17 7:02 ` Anshuman Khandual
@ 2024-05-20 1:51 ` Miaohe Lin
0 siblings, 0 replies; 3+ messages in thread
From: Miaohe Lin @ 2024-05-20 1:51 UTC (permalink / raw)
To: Anshuman Khandual, akpm
Cc: shy828301, nao.horiguchi, xuyu, david, osalvador, linux-mm, linux-kernel
On 2024/5/17 15:02, Anshuman Khandual wrote:
> On 5/16/24 17:56, 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
>
> Small nit, a typo in here ^^^^^ s/unexpectly/unexpectedly/.
Thanks for finding out this typo. And thanks Andrew for fixing the typo.
>
>> 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")
>
> The target commit looks right.
>
>> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
>> Acked-by: David Hildenbrand <david@redhat.com>
>> Reviewed-by: Yang Shi <shy828301@gmail.com>
>> Reviewed-by: Oscar Salvador <osalvador@suse.de>
>> Cc: <stable@vger.kernel.org>
>> ---
>> v3:
>> Move up is_huge_zero_folio() check and change return value to
>> -EOPNOTSUPP per Oscar.
>> Collect Reviewed-by and Acked-by tag. Thanks.
>> v2:
>> Change to simply check for the huge zero page per David. Thanks.
>> ---
>> mm/memory-failure.c | 7 +++++++
>> 1 file changed, 7 insertions(+)
>>
>> 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);
>
> This patch applies on latest linux-next but not on latest mainline as
> is_huge_zero_folio() is absent there.
It could be simply replaced with is_huge_zero_page().
>
> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Thanks.
.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2024-05-16 12:26 [PATCH v3] mm/huge_memory: don't unpoison huge_zero_folio Miaohe Lin
2024-05-17 7:02 ` Anshuman Khandual
2024-05-20 1:51 ` Miaohe Lin
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