From: Andrew Morton <akpm@linux-foundation.org>
To: mm-commits@vger.kernel.org,xuyu@linux.alibaba.com,willy@infradead.org,stable@vger.kernel.org,shy828301@gmail.com,nao.horiguchi@gmail.com,david@redhat.com,linmiaohe@huawei.com,akpm@linux-foundation.org
Subject: [alternative-merged] mm-huge_memory-mark-huge_zero_page-reserved.patch removed from -mm tree
Date: Tue, 14 May 2024 15:01:57 -0700 [thread overview]
Message-ID: <20240514220158.56A8EC32786@smtp.kernel.org> (raw)
The quilt patch titled
Subject: mm/huge_memory: mark huge_zero_page reserved
has been removed from the -mm tree. Its filename was
mm-huge_memory-mark-huge_zero_page-reserved.patch
This patch was dropped because an alternative patch was or shall be merged
------------------------------------------------------
From: Miaohe Lin <linmiaohe@huawei.com>
Subject: mm/huge_memory: mark huge_zero_page reserved
Date: Sat, 11 May 2024 11:54:35 +0800
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_page
without increasing the page refcnt. But then unpoison_memory() will
decrease the page refcnt unexpectly as it appears like a successfully
hwpoisoned page leading to VM_BUG_ON_PAGE(page_ref_count(page) == 0)
when releasing huge_zero_page.
Fix this issue by marking huge_zero_page reserved. So unpoison_memory()
will skip this page. This will make it consistent with ZERO_PAGE case too.
Link: https://lkml.kernel.org/r/20240511035435.1477004-1-linmiaohe@huawei.com
Fixes: 478d134e9506 ("mm/huge_memory: do not overkill when splitting huge_zero_page")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Xu Yu <xuyu@linux.alibaba.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/huge_memory.c | 2 ++
1 file changed, 2 insertions(+)
--- a/mm/huge_memory.c~mm-huge_memory-mark-huge_zero_page-reserved
+++ a/mm/huge_memory.c
@@ -212,6 +212,7 @@ retry:
folio_put(zero_folio);
goto retry;
}
+ __SetPageReserved(zero_page);
WRITE_ONCE(huge_zero_pfn, folio_pfn(zero_folio));
/* We take additional reference here. It will be put back by shrinker */
@@ -264,6 +265,7 @@ static unsigned long shrink_huge_zero_pa
struct folio *zero_folio = xchg(&huge_zero_folio, NULL);
BUG_ON(zero_folio == NULL);
WRITE_ONCE(huge_zero_pfn, ~0UL);
+ __ClearPageReserved(zero_page);
folio_put(zero_folio);
return HPAGE_PMD_NR;
}
_
Patches currently in -mm which might be from linmiaohe@huawei.com are
reply other threads:[~2024-05-14 22:01 UTC|newest]
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