Commit Graph

524 Commits

Author SHA1 Message Date
Miaohe Lin 8cf360b9d6 mm/memory-failure: fix handling of dissolved but not taken off from buddy pages
When I did memory failure tests recently, below panic occurs:

page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x8cee00
flags: 0x6fffe0000000000(node=1|zone=2|lastcpupid=0x7fff)
raw: 06fffe0000000000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000009 00000000ffffffff 0000000000000000
page dumped because: VM_BUG_ON_PAGE(!PageBuddy(page))
------------[ cut here ]------------
kernel BUG at include/linux/page-flags.h:1009!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
RIP: 0010:__del_page_from_free_list+0x151/0x180
RSP: 0018:ffffa49c90437998 EFLAGS: 00000046
RAX: 0000000000000035 RBX: 0000000000000009 RCX: ffff8dd8dfd1c9c8
RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff8dd8dfd1c9c0
RBP: ffffd901233b8000 R08: ffffffffab5511f8 R09: 0000000000008c69
R10: 0000000000003c15 R11: ffffffffab5511f8 R12: ffff8dd8fffc0c80
R13: 0000000000000001 R14: ffff8dd8fffc0c80 R15: 0000000000000009
FS:  00007ff916304740(0000) GS:ffff8dd8dfd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055eae50124c8 CR3: 00000008479e0000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __rmqueue_pcplist+0x23b/0x520
 get_page_from_freelist+0x26b/0xe40
 __alloc_pages_noprof+0x113/0x1120
 __folio_alloc_noprof+0x11/0xb0
 alloc_buddy_hugetlb_folio.isra.0+0x5a/0x130
 __alloc_fresh_hugetlb_folio+0xe7/0x140
 alloc_pool_huge_folio+0x68/0x100
 set_max_huge_pages+0x13d/0x340
 hugetlb_sysctl_handler_common+0xe8/0x110
 proc_sys_call_handler+0x194/0x280
 vfs_write+0x387/0x550
 ksys_write+0x64/0xe0
 do_syscall_64+0xc2/0x1d0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff916114887
RSP: 002b:00007ffec8a2fd78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055eae500e350 RCX: 00007ff916114887
RDX: 0000000000000004 RSI: 000055eae500e390 RDI: 0000000000000003
RBP: 000055eae50104c0 R08: 0000000000000000 R09: 000055eae50104c0
R10: 0000000000000077 R11: 0000000000000246 R12: 0000000000000004
R13: 0000000000000004 R14: 00007ff916216b80 R15: 00007ff916216a00
 </TASK>
Modules linked in: mce_inject hwpoison_inject
---[ end trace 0000000000000000 ]---

And before the panic, there had an warning about bad page state:

BUG: Bad page state in process page-types  pfn:8cee00
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x8cee00
flags: 0x6fffe0000000000(node=1|zone=2|lastcpupid=0x7fff)
page_type: 0xffffff7f(buddy)
raw: 06fffe0000000000 ffffd901241c0008 ffffd901240f8008 0000000000000000
raw: 0000000000000000 0000000000000009 00000000ffffff7f 0000000000000000
page dumped because: nonzero mapcount
Modules linked in: mce_inject hwpoison_inject
CPU: 8 PID: 154211 Comm: page-types Not tainted 6.9.0-rc4-00499-g5544ec3178e2-dirty #22
Call Trace:
 <TASK>
 dump_stack_lvl+0x83/0xa0
 bad_page+0x63/0xf0
 free_unref_page+0x36e/0x5c0
 unpoison_memory+0x50b/0x630
 simple_attr_write_xsigned.constprop.0.isra.0+0xb3/0x110
 debugfs_attr_write+0x42/0x60
 full_proxy_write+0x5b/0x80
 vfs_write+0xcd/0x550
 ksys_write+0x64/0xe0
 do_syscall_64+0xc2/0x1d0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f189a514887
RSP: 002b:00007ffdcd899718 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f189a514887
RDX: 0000000000000009 RSI: 00007ffdcd899730 RDI: 0000000000000003
RBP: 00007ffdcd8997a0 R08: 0000000000000000 R09: 00007ffdcd8994b2
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdcda199a8
R13: 0000000000404af1 R14: 000000000040ad78 R15: 00007f189a7a5040
 </TASK>

The root cause should be the below race:

 memory_failure
  try_memory_failure_hugetlb
   me_huge_page
    __page_handle_poison
     dissolve_free_hugetlb_folio
     drain_all_pages -- Buddy page can be isolated e.g. for compaction.
     take_page_off_buddy -- Failed as page is not in the buddy list.
	     -- Page can be putback into buddy after compaction.
    page_ref_inc -- Leads to buddy page with refcnt = 1.

Then unpoison_memory() can unpoison the page and send the buddy page back
into buddy list again leading to the above bad page state warning.  And
bad_page() will call page_mapcount_reset() to remove PageBuddy from buddy
page leading to later VM_BUG_ON_PAGE(!PageBuddy(page)) when trying to
allocate this page.

Fix this issue by only treating __page_handle_poison() as successful when
it returns 1.

Link: https://lkml.kernel.org/r/20240523071217.1696196-1-linmiaohe@huawei.com
Fixes: ceaf8fbea7 ("mm, hwpoison: skip raw hwpoison page in freeing 1GB hugepage")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-24 11:55:08 -07:00
Miaohe Lin fe6f86f4b4 mm/huge_memory: don't unpoison huge_zero_folio
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 unexpectedly 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.

Link: https://lkml.kernel.org/r/20240516122608.22610-1-linmiaohe@huawei.com
Fixes: 478d134e95 ("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>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Xu Yu <xuyu@linux.alibaba.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-24 11:55:05 -07:00
Matthew Wilcox (Oracle) 89f5c54b22 memory-failure: remove calls to page_mapping()
This is mostly just inlining page_mapping() into the two callers.

Link: https://lkml.kernel.org/r/20240423225552.4113447-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:48 -07:00
Matthew Wilcox (Oracle) b650e1d2ae mm/memory-failure: pass the folio to collect_procs_ksm()
We've already calculated it, so pass it in instead of recalculating it in
collect_procs_ksm().

Link: https://lkml.kernel.org/r/20240412193510.2356957-12-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:47 -07:00
Matthew Wilcox (Oracle) 0edb5b282a mm/memory-failure: use folio functions throughout collect_procs()
Saves a couple of calls to compound_head().

Link: https://lkml.kernel.org/r/20240412193510.2356957-11-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:47 -07:00
Matthew Wilcox (Oracle) ee299e9849 mm/memory-failure: add some folio conversions to unpoison_memory
Some of these folio APIs didn't exist when the unpoison_memory()
conversion was done originally.

Link: https://lkml.kernel.org/r/20240412193510.2356957-10-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:46 -07:00
Matthew Wilcox (Oracle) 03468a0f52 mm/memory-failure: convert hwpoison_user_mappings to take a folio
Pass the folio from the callers, and use it throughout instead of hpage. 
Saves dozens of calls to compound_head().

Link: https://lkml.kernel.org/r/20240412193510.2356957-9-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:46 -07:00
Matthew Wilcox (Oracle) 5dba5c356a mm/memory-failure: convert memory_failure() to use a folio
Saves dozens of calls to compound_head().

Link: https://lkml.kernel.org/r/20240412193510.2356957-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:46 -07:00
Matthew Wilcox (Oracle) 6e8cda4c2c mm: convert hugetlb_page_mapping_lock_write to folio
The page is only used to get the mapping, so the folio will do just as
well.  Both callers already have a folio available, so this saves a call
to compound_head().

Link: https://lkml.kernel.org/r/20240412193510.2356957-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jane Chu  <jane.chu@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:46 -07:00
Matthew Wilcox (Oracle) fed5348ee2 mm/memory-failure: convert shake_page() to shake_folio()
Removes two calls to compound_head().  Move the prototype to internal.h;
we definitely don't want code outside mm using it.

Link: https://lkml.kernel.org/r/20240412193510.2356957-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:45 -07:00
Matthew Wilcox (Oracle) 37bc2ff506 mm: return the address from page_mapped_in_vma()
The only user of this function calls page_address_in_vma() immediately
after page_mapped_in_vma() calculates it and uses it to return true/false.
Return the address instead, allowing memory-failure to skip the call to
page_address_in_vma().

Link: https://lkml.kernel.org/r/20240412193510.2356957-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:45 -07:00
Matthew Wilcox (Oracle) f2b37197c2 mm/memory-failure: pass addr to __add_to_kill()
Handle anon/file folios the same way as KSM & DAX folios by passing in the
address.

Link: https://lkml.kernel.org/r/20240412193510.2356957-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:45 -07:00
Matthew Wilcox (Oracle) 1c0501e831 mm/memory-failure: remove fsdax_pgoff argument from __add_to_kill
Patch series "Some cleanups for memory-failure", v3.

A lot of folio conversions, plus some other simplifications. 


This patch (of 11):

Unify the KSM and DAX codepaths by calculating the addr in
add_to_kill_fsdax() instead of telling __add_to_kill() to calculate it.

Link: https://lkml.kernel.org/r/20240412193510.2356957-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20240412193510.2356957-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:44 -07:00
Sidhartha Kumar 54fa49b2e0 mm/hugetlb: convert dissolve_free_huge_pages() to folios
Allows us to rename dissolve_free_huge_pages() to
dissolve_free_hugetlb_folio(). Convert one caller to pass in a folio
directly and use page_folio() to convert the caller in mm/memory-failure.

[sidhartha.kumar@oracle.com: remove unneeded `extern']
  Link: https://lkml.kernel.org/r/71760ed4-e80d-493a-95ea-2545414b1aba@oracle.com
[sidhartha.kumar@oracle.com: v2]
  Link: https://lkml.kernel.org/r/20240412182139.120871-1-sidhartha.kumar@oracle.com
Link: https://lkml.kernel.org/r/20240411164756.261178-1-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:35 -07:00
David Hildenbrand 33d844bb84 mm/memory-failure: use folio_mapcount() in hwpoison_user_mappings()
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary.  We can only unmap full folios; page_mapped(), which
we check here, is translated to folio_mapped() -- based on
folio_mapcount().  So let's print the folio mapcount instead.

Link: https://lkml.kernel.org/r/20240409192301.907377-10-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:29 -07:00
Joel Granados 7998df0b64 memory: remove the now superfluous sentinel element from ctl_table array
This commit comes at the tail end of a greater effort to remove the empty
elements at the end of the ctl_table arrays (sentinels) which will reduce
the overall build time size of the kernel and run time memory bloat by ~64
bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)

Remove sentinel from all files under mm/ that register a sysctl table.

Link: https://lkml.kernel.org/r/20240328-jag-sysctl_remset_misc-v1-1-47c1463b3af2@samsung.com
Signed-off-by: Joel Granados <j.granados@samsung.com>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:32 -07:00
Matthew Wilcox (Oracle) e0abfbb671 mm: rename vma_pgoff_address back to vma_address
With all callers converted, we can use the nice shorter name.  Take this
opportunity to reorder the arguments to the logical order (larger object
first).

Link: https://lkml.kernel.org/r/20240328225831.1765286-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:31 -07:00
Baolin Wang e42dfe4e0a mm: record the migration reason for struct migration_target_control
Patch series "make the hugetlb migration strategy consistent", v2.

As discussed in previous thread [1], there is an inconsistency when
handling hugetlb migration.  When handling the migration of freed hugetlb,
it prevents fallback to other NUMA nodes in
alloc_and_dissolve_hugetlb_folio().  However, when dealing with in-use
hugetlb, it allows fallback to other NUMA nodes in
alloc_hugetlb_folio_nodemask(), which can break the per-node hugetlb pool
and might result in unexpected failures when node bound workloads doesn't
get what is asssumed available.

This patchset tries to make the hugetlb migration strategy more clear
and consistent. Please find details in each patch.

[1]
https://lore.kernel.org/all/6f26ce22d2fcd523418a085f2c588fe0776d46e7.1706794035.git.baolin.wang@linux.alibaba.com/


This patch (of 2):

To support different hugetlb allocation strategies during hugetlb
migration based on various migration reasons, record the migration reason
in the migration_target_control structure as a preparation.

Link: https://lkml.kernel.org/r/cover.1709719720.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/7b95d4981e07211f57139fc5b1f7ce91b920cee4.1709719720.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:06 -07:00
Matthew Wilcox (Oracle) 46df8e73a4 mm: free up PG_slab
Reclaim the Slab page flag by using a spare bit in PageType.  We are
perennially short of page flags for various purposes, and now that the
original SLAB allocator has been retired, SLUB does not use the
mapcount/page_type field.  This lets us remove a number of special cases
for ignoring mapcount on Slab pages.

[willy@infradead.org: update vmcoreinfo]
  Link: https://lkml.kernel.org/r/ZgGV-O8WYQ_83kxp@casper.infradead.org
Link: https://lkml.kernel.org/r/20240321142448.1645400-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:00 -07:00
Miaohe Lin 1983184c22 mm/memory-failure: fix deadlock when hugetlb_optimize_vmemmap is enabled
When I did hard offline test with hugetlb pages, below deadlock occurs:

======================================================
WARNING: possible circular locking dependency detected
6.8.0-11409-gf6cef5f8c37f #1 Not tainted
------------------------------------------------------
bash/46904 is trying to acquire lock:
ffffffffabe68910 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_slow_dec+0x16/0x60

but task is already holding lock:
ffffffffabf92ea8 (pcp_batch_high_lock){+.+.}-{3:3}, at: zone_pcp_disable+0x16/0x40

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (pcp_batch_high_lock){+.+.}-{3:3}:
       __mutex_lock+0x6c/0x770
       page_alloc_cpu_online+0x3c/0x70
       cpuhp_invoke_callback+0x397/0x5f0
       __cpuhp_invoke_callback_range+0x71/0xe0
       _cpu_up+0xeb/0x210
       cpu_up+0x91/0xe0
       cpuhp_bringup_mask+0x49/0xb0
       bringup_nonboot_cpus+0xb7/0xe0
       smp_init+0x25/0xa0
       kernel_init_freeable+0x15f/0x3e0
       kernel_init+0x15/0x1b0
       ret_from_fork+0x2f/0x50
       ret_from_fork_asm+0x1a/0x30

-> #0 (cpu_hotplug_lock){++++}-{0:0}:
       __lock_acquire+0x1298/0x1cd0
       lock_acquire+0xc0/0x2b0
       cpus_read_lock+0x2a/0xc0
       static_key_slow_dec+0x16/0x60
       __hugetlb_vmemmap_restore_folio+0x1b9/0x200
       dissolve_free_huge_page+0x211/0x260
       __page_handle_poison+0x45/0xc0
       memory_failure+0x65e/0xc70
       hard_offline_page_store+0x55/0xa0
       kernfs_fop_write_iter+0x12c/0x1d0
       vfs_write+0x387/0x550
       ksys_write+0x64/0xe0
       do_syscall_64+0xca/0x1e0
       entry_SYSCALL_64_after_hwframe+0x6d/0x75

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(pcp_batch_high_lock);
                               lock(cpu_hotplug_lock);
                               lock(pcp_batch_high_lock);
  rlock(cpu_hotplug_lock);

 *** DEADLOCK ***

5 locks held by bash/46904:
 #0: ffff98f6c3bb23f0 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x64/0xe0
 #1: ffff98f6c328e488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0xf8/0x1d0
 #2: ffff98ef83b31890 (kn->active#113){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x100/0x1d0
 #3: ffffffffabf9db48 (mf_mutex){+.+.}-{3:3}, at: memory_failure+0x44/0xc70
 #4: ffffffffabf92ea8 (pcp_batch_high_lock){+.+.}-{3:3}, at: zone_pcp_disable+0x16/0x40

stack backtrace:
CPU: 10 PID: 46904 Comm: bash Kdump: loaded Not tainted 6.8.0-11409-gf6cef5f8c37f #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x68/0xa0
 check_noncircular+0x129/0x140
 __lock_acquire+0x1298/0x1cd0
 lock_acquire+0xc0/0x2b0
 cpus_read_lock+0x2a/0xc0
 static_key_slow_dec+0x16/0x60
 __hugetlb_vmemmap_restore_folio+0x1b9/0x200
 dissolve_free_huge_page+0x211/0x260
 __page_handle_poison+0x45/0xc0
 memory_failure+0x65e/0xc70
 hard_offline_page_store+0x55/0xa0
 kernfs_fop_write_iter+0x12c/0x1d0
 vfs_write+0x387/0x550
 ksys_write+0x64/0xe0
 do_syscall_64+0xca/0x1e0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7fc862314887
Code: 10 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
RSP: 002b:00007fff19311268 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007fc862314887
RDX: 000000000000000c RSI: 000056405645fe10 RDI: 0000000000000001
RBP: 000056405645fe10 R08: 00007fc8623d1460 R09: 000000007fffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000c
R13: 00007fc86241b780 R14: 00007fc862417600 R15: 00007fc862416a00

In short, below scene breaks the lock dependency chain:

 memory_failure
  __page_handle_poison
   zone_pcp_disable -- lock(pcp_batch_high_lock)
   dissolve_free_huge_page
    __hugetlb_vmemmap_restore_folio
     static_key_slow_dec
      cpus_read_lock -- rlock(cpu_hotplug_lock)

Fix this by calling drain_all_pages() instead.

This issue won't occur until commit a6b40850c4 ("mm: hugetlb: replace
hugetlb_free_vmemmap_enabled with a static_key").  As it introduced
rlock(cpu_hotplug_lock) in dissolve_free_huge_page() code path while
lock(pcp_batch_high_lock) is already in the __page_handle_poison().

[linmiaohe@huawei.com: extend comment per Oscar]
[akpm@linux-foundation.org: reflow block comment]
Link: https://lkml.kernel.org/r/20240407085456.2798193-1-linmiaohe@huawei.com
Fixes: a6b40850c4 ("mm: hugetlb: replace hugetlb_free_vmemmap_enabled with a static_key")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-16 15:39:50 -07:00
Miaohe Lin 2fde9e7f9e mm/memory-failure: fix crash in split_huge_page_to_list from soft_offline_page
When I did soft offline stress test, a machine was observed to crash with
the following message:

  kernel BUG at include/linux/memcontrol.h:554!
  invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
  CPU: 5 PID: 3837 Comm: hwpoison.sh Not tainted 6.7.0-next-20240112-00001-g8ecf3e7fb7c8-dirty #97
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
  RIP: 0010:folio_memcg+0xaf/0xd0
  Code: 10 5b 5d c3 cc cc cc cc 48 c7 c6 08 b1 f2 b2 48 89 ef e8 b4 c5 f8 ff 90 0f 0b 48 c7 c6 d0 b0 f2 b2 48 89 ef e8 a2 c5 f8 ff 90 <0f> 0b 48 c7 c6 08 b1 f2 b2 48 89 ef e8 90 c5 f8 ff 90 0f 0b 66 66
  RSP: 0018:ffffb6c043657c98 EFLAGS: 00000296
  RAX: 000000000000004b RBX: ffff932bc1d1e401 RCX: ffff933abfb5c908
  RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff933abfb5c900
  RBP: ffffea6f04019080 R08: ffffffffb3338ce8 R09: 0000000000009ffb
  R10: 00000000000004dd R11: ffffffffb3308d00 R12: ffffea6f04019080
  R13: ffffea6f04019080 R14: 0000000000000001 R15: ffffb6c043657da0
  FS:  00007f6c60f6b740(0000) GS:ffff933abfb40000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000559c3bc8b980 CR3: 0000000107f1c000 CR4: 00000000000006f0
  Call Trace:
   <TASK>
   split_huge_page_to_list+0x4d/0x1380
   try_to_split_thp_page+0x3a/0xf0
   soft_offline_page+0x1ea/0x8a0
   soft_offline_page_store+0x52/0x90
   kernfs_fop_write_iter+0x118/0x1b0
   vfs_write+0x30b/0x430
   ksys_write+0x5e/0xe0
   do_syscall_64+0xb0/0x1b0
   entry_SYSCALL_64_after_hwframe+0x6d/0x75
  RIP: 0033:0x7f6c60d14697
  Code: 10 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
  RSP: 002b:00007ffe9b72b8d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007f6c60d14697
  RDX: 000000000000000c RSI: 0000559c3bc8b980 RDI: 0000000000000001
  RBP: 0000559c3bc8b980 R08: 00007f6c60dd1460 R09: 000000007fffffff
  R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000c
  R13: 00007f6c60e1a780 R14: 00007f6c60e16600 R15: 00007f6c60e15a00

The problem is that page->mapping is overloaded with slab->slab_list or
slabs fields now, so slab pages could be taken as non-LRU movable pages if
field slabs contains PAGE_MAPPING_MOVABLE or slab_list->prev is set to
LIST_POISON2.  These slab pages will be treated as thp later leading to
crash in split_huge_page_to_list().

Link: https://lkml.kernel.org/r/20240126065837.2100184-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20240124084014.1772906-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Fixes: 130d4df573 ("mm/sl[au]b: rearrange struct slab fields to allow larger rcu_head")
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-07 21:20:34 -08:00
Sidhartha Kumar 19d3e22180 fs/hugetlbfs/inode.c: mm/memory-failure.c: fix hugetlbfs hwpoison handling
has_extra_refcount() makes the assumption that the page cache adds a ref
count of 1 and subtracts this in the extra_pins case.  Commit a08c7193e4
(mm/filemap: remove hugetlb special casing in filemap.c) modifies
__filemap_add_folio() by calling folio_ref_add(folio, nr); for all cases
(including hugtetlb) where nr is the number of pages in the folio.  We
should adjust the number of references coming from the page cache by
subtracing the number of pages rather than 1.

In hugetlbfs_read_iter(), folio_test_has_hwpoisoned() is testing the wrong
flag as, in the hugetlb case, memory-failure code calls
folio_test_set_hwpoison() to indicate poison.  folio_test_hwpoison() is
the correct function to test for that flag.

After these fixes, the hugetlb hwpoison read selftest passes all cases.

Link: https://lkml.kernel.org/r/20240112180840.367006-1-sidhartha.kumar@oracle.com
Fixes: a08c7193e4 ("mm/filemap: remove hugetlb special casing in filemap.c")
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Closes: https://lore.kernel.org/linux-mm/20230713001833.3778937-1-jiaqiyan@google.com/T/#m8e1469119e5b831bbd05d495f96b842e4a1c5519
Reported-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Muchun Song <muchun.song@linux.dev>
Cc: James Houghton <jthoughton@google.com>
Cc: Jiaqi Yan <jiaqiyan@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: <stable@vger.kernel.org>	[6.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-01-25 23:52:20 -08:00
Linus Torvalds 12958e9c4c New code for 6.8:
* New features/functionality
     * Online repair
       * Reserve disk space for online repairs.
       * Fix misinteraction between the AIL and btree bulkloader because of
         which the bulk load fails to queue a buffer for writeback if it
         happens to be on the AIL list.
       * Prevent transaction reservation overflows when reaping blocks during
         online repair.
       * Whenever possible, bulkloader now copies multiple records into a
         block.
       * Support repairing of
         1. Per-AG free space, inode and refcount btrees.
 	2. Ondisk inodes.
 	3. File data and attribute fork mappings.
       * Verify the contents of
         1. Inode and data fork of realtime bitmap file.
 	2. Quota files.
     * Introduce MF_MEM_PRE_REMOVE. This will be used to notify tasks about
       a pmem device being removed.
 
   * Bug fixes
     * Fix memory leak of recovered attri intent items.
     * Fix UAF during log intent recovery.
     * Fix realtime geometry integer overflows.
     * Prevent scrub from live locking in xchk_iget.
     * Prevent fs shutdown when removing files during low free disk space.
     * Prevent transaction reservation overflow when extending an RT device.
     * Prevent incorrect warning from being printed when extending a
       filesystem.
     * Fix an off-by-one error in xreap_agextent_binval.
     * Serialize access to perag radix tree during deletion operation.
     * Fix perag memory leak during growfs.
     * Allow allocation of minlen realtime extent when the maximum sized
       realtime free extent is minlen in size.
 
   * Cleanups
     * Remove duplicate boilerplate code spread across functionality associated
       with different log items.
     * Cleanup resblks interfaces.
     * Pass defer ops pointer to defer helpers instead of an enum.
     * Initialize di_crc in xfs_log_dinode to prevent KMSAN warnings.
     * Use static_assert() instead of BUILD_BUG_ON_MSG() to validate size of
       structures and structure member offsets. This is done in order to be
       able to share the code with userspace.
     * Move XFS documentation under a new directory specific to XFS.
     * Do not invoke deferred ops' ->create_done callback if the deferred
       operation does not have an intent item associated with it.
     * Remove duplicate inclusion of header files from scrub/health.c.
     * Refactor Realtime code.
     * Cleanup attr code.
 
 Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQQjMC4mbgVeU7MxEIYH7y4RirJu9AUCZZJQbwAKCRAH7y4RirJu
 9JjkAP9Zg0QZNmAMsZwvgEBbuF/OnHKl4GmPA5uq0jPmSWCOqAEA0HjlOmuNfQWn
 93fIw6CPbt+9QCluTYBwUisKLIJ/wgA=
 =qmO0
 -----END PGP SIGNATURE-----

Merge tag 'xfs-6.8-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs updates from Chandan Babu:
 "New features/functionality:
   - Online repair:
       - Reserve disk space for online repairs
       - Fix misinteraction between the AIL and btree bulkloader because
         of which the bulk load fails to queue a buffer for writeback if
         it happens to be on the AIL list
       - Prevent transaction reservation overflows when reaping blocks
         during online repair
       - Whenever possible, bulkloader now copies multiple records into
         a block
       - Support repairing of
           1. Per-AG free space, inode and refcount btrees
           2. Ondisk inodes
           3. File data and attribute fork mappings
       - Verify the contents of
           1. Inode and data fork of realtime bitmap file
           2. Quota files
   - Introduce MF_MEM_PRE_REMOVE. This will be used to notify tasks
     about a pmem device being removed

  Bug fixes:
   - Fix memory leak of recovered attri intent items
   - Fix UAF during log intent recovery
   - Fix realtime geometry integer overflows
   - Prevent scrub from live locking in xchk_iget
   - Prevent fs shutdown when removing files during low free disk space
   - Prevent transaction reservation overflow when extending an RT
     device
   - Prevent incorrect warning from being printed when extending a
     filesystem
   - Fix an off-by-one error in xreap_agextent_binval
   - Serialize access to perag radix tree during deletion operation
   - Fix perag memory leak during growfs
   - Allow allocation of minlen realtime extent when the maximum sized
     realtime free extent is minlen in size

  Cleanups:
   - Remove duplicate boilerplate code spread across functionality
     associated with different log items
   - Cleanup resblks interfaces
   - Pass defer ops pointer to defer helpers instead of an enum
   - Initialize di_crc in xfs_log_dinode to prevent KMSAN warnings
   - Use static_assert() instead of BUILD_BUG_ON_MSG() to validate size
     of structures and structure member offsets. This is done in order
     to be able to share the code with userspace
   - Move XFS documentation under a new directory specific to XFS
   - Do not invoke deferred ops' ->create_done callback if the deferred
     operation does not have an intent item associated with it
   - Remove duplicate inclusion of header files from scrub/health.c
   - Refactor Realtime code
   - Cleanup attr code"

* tag 'xfs-6.8-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (123 commits)
  xfs: use the op name in trace_xlog_intent_recovery_failed
  xfs: fix a use after free in xfs_defer_finish_recovery
  xfs: turn the XFS_DA_OP_REPLACE checks in xfs_attr_shortform_addname into asserts
  xfs: remove xfs_attr_sf_hdr_t
  xfs: remove struct xfs_attr_shortform
  xfs: use xfs_attr_sf_findname in xfs_attr_shortform_getvalue
  xfs: remove xfs_attr_shortform_lookup
  xfs: simplify xfs_attr_sf_findname
  xfs: move the xfs_attr_sf_lookup tracepoint
  xfs: return if_data from xfs_idata_realloc
  xfs: make if_data a void pointer
  xfs: fold xfs_rtallocate_extent into xfs_bmap_rtalloc
  xfs: simplify and optimize the RT allocation fallback cascade
  xfs: reorder the minlen and prod calculations in xfs_bmap_rtalloc
  xfs: remove XFS_RTMIN/XFS_RTMAX
  xfs: remove rt-wrappers from xfs_format.h
  xfs: factor out a xfs_rtalloc_sumlevel helper
  xfs: tidy up xfs_rtallocate_extent_exact
  xfs: merge the calls to xfs_rtallocate_range in xfs_rtallocate_block
  xfs: reflow the tail end of xfs_rtallocate_extent_block
  ...
2024-01-10 08:45:22 -08:00
David Hildenbrand 4d8f7418e8 mm/rmap: remove page_remove_rmap()
All callers are gone, let's remove it and some leftover traces.

Link: https://lkml.kernel.org/r/20231220224504.646757-33-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29 11:58:55 -08:00
Andrew Morton a721aeac8b sync mm-stable with mm-hotfixes-stable to pick up depended-upon changes 2023-12-20 14:47:18 -08:00
Matthew Wilcox (Oracle) 39ebd6dce6 mm/memory-failure: cast index to loff_t before shifting it
On 32-bit systems, we'll lose the top bits of index because arithmetic
will be performed in unsigned long instead of unsigned long long.  This
affects files over 4GB in size.

Link: https://lkml.kernel.org/r/20231218135837.3310403-4-willy@infradead.org
Fixes: 6100e34b25 ("mm, memory_failure: Teach memory_failure() about dev_pagemap pages")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-20 13:46:20 -08:00
Matthew Wilcox (Oracle) c79c5a0a00 mm/memory-failure: check the mapcount of the precise page
A process may map only some of the pages in a folio, and might be missed
if it maps the poisoned page but not the head page.  Or it might be
unnecessarily hit if it maps the head page, but not the poisoned page.

Link: https://lkml.kernel.org/r/20231218135837.3310403-3-willy@infradead.org
Fixes: 7af446a841 ("HWPOISON, hugetlb: enable error handling path for hugepage")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-20 13:46:19 -08:00
Matthew Wilcox (Oracle) 376907f3a0 mm/memory-failure: pass the folio and the page to collect_procs()
Patch series "Three memory-failure fixes".

I've been looking at the memory-failure code and I believe I have found
three bugs that need fixing -- one going all the way back to 2010!  I'll
have more patches later to use folios more extensively but didn't want
these bugfixes to get caught up in that.


This patch (of 3):

Both collect_procs_anon() and collect_procs_file() iterate over the VMA
interval trees looking for a single pgoff, so it is wrong to look for the
pgoff of the head page as is currently done.  However, it is also wrong to
look at page->mapping of the precise page as this is invalid for tail
pages.  Clear up the confusion by passing both the folio and the precise
page to collect_procs().

Link: https://lkml.kernel.org/r/20231218135837.3310403-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20231218135837.3310403-2-willy@infradead.org
Fixes: 415c64c145 ("mm/memory-failure: split thp earlier in memory error handling")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-20 13:46:19 -08:00
Matthew Wilcox (Oracle) af7628d6ec fs: convert error_remove_page to error_remove_folio
There were already assertions that we were not passing a tail page to
error_remove_page(), so make the compiler enforce that by converting
everything to pass and use a folio.

Link: https://lkml.kernel.org/r/20231117161447.2461643-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 16:51:42 -08:00
Matthew Wilcox (Oracle) e130b6514e memory-failure: convert truncate_error_page to truncate_error_folio
Both callers now have a folio, so pass it in.  Nothing downstream was
expecting a tail page; that's asserted in generic_error_remove_page(), for
example.

Link: https://lkml.kernel.org/r/20231117161447.2461643-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 16:51:42 -08:00
Matthew Wilcox (Oracle) b6fd410c32 memory-failure: use a folio in me_huge_page()
This function was already explicitly calling compound_head();
unfortunately the compiler can't know that and elide the redundant calls
to compound_head() buried in page_mapping(), unlock_page(), etc.  Switch
to using a folio, which does let us elide these calls.

Link: https://lkml.kernel.org/r/20231117161447.2461643-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 16:51:42 -08:00
Matthew Wilcox (Oracle) f709239357 memory-failure: convert delete_from_lru_cache() to take a folio
All three callers now have a folio; pass it in instead of the page.
Saves five calls to compound_head().

Link: https://lkml.kernel.org/r/20231117161447.2461643-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 16:51:41 -08:00
Matthew Wilcox (Oracle) 6304b531cd memory-failure: use a folio in me_pagecache_dirty()
Replaces three hidden calls to compound_head() with one visible one.

Link: https://lkml.kernel.org/r/20231117161447.2461643-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 16:51:41 -08:00
Matthew Wilcox (Oracle) 3d47e31790 memory-failure: use a folio in me_pagecache_clean()
Patch series "Convert aops->error_remove_page to ->error_remove_folio".

This is a memory-failure patch series which converts a lot of uses of page
APIs into folio APIs with the usual benefits.  


This patch (of 6):

Replaces three hidden calls to compound_head() with one visible one.
Fix up a few comments while I'm modifying this function.

Link: https://lkml.kernel.org/r/20231117161447.2461643-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20231117161447.2461643-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 16:51:41 -08:00
Matthew Wilcox (Oracle) 761d79fbad mm: convert isolate_page() to mf_isolate_folio()
The only caller now has a folio, so pass it in and operate on it.  Saves
many page->folio conversions and introduces only one folio->page
conversion when calling isolate_movable_page().

Link: https://lkml.kernel.org/r/20231108182809.602073-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 16:51:38 -08:00
Matthew Wilcox (Oracle) 049b26048d mm: convert soft_offline_in_use_page() to use a folio
Replace the existing head-page logic with folio logic.

Link: https://lkml.kernel.org/r/20231108182809.602073-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 16:51:38 -08:00
Matthew Wilcox (Oracle) 19369d866a mm: use mapping_evict_folio() in truncate_error_page()
We already have the folio and the mapping, so replace the call to
invalidate_inode_page() with mapping_evict_folio().

Link: https://lkml.kernel.org/r/20231108182809.602073-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 16:51:38 -08:00
Shiyang Ruan fa422b353d mm, pmem, xfs: Introduce MF_MEM_PRE_REMOVE for unbind
Now, if we suddenly remove a PMEM device(by calling unbind) which
contains FSDAX while programs are still accessing data in this device,
e.g.:
```
 $FSSTRESS_PROG -d $SCRATCH_MNT -n 99999 -p 4 &
 # $FSX_PROG -N 1000000 -o 8192 -l 500000 $SCRATCH_MNT/t001 &
 echo "pfn1.1" > /sys/bus/nd/drivers/nd_pmem/unbind
```
it could come into an unacceptable state:
  1. device has gone but mount point still exists, and umount will fail
       with "target is busy"
  2. programs will hang and cannot be killed
  3. may crash with NULL pointer dereference

To fix this, we introduce a MF_MEM_PRE_REMOVE flag to let it know that we
are going to remove the whole device, and make sure all related processes
could be notified so that they could end up gracefully.

This patch is inspired by Dan's "mm, dax, pmem: Introduce
dev_pagemap_failure()"[1].  With the help of dax_holder and
->notify_failure() mechanism, the pmem driver is able to ask filesystem
on it to unmap all files in use, and notify processes who are using
those files.

Call trace:
trigger unbind
 -> unbind_store()
  -> ... (skip)
   -> devres_release_all()
    -> kill_dax()
     -> dax_holder_notify_failure(dax_dev, 0, U64_MAX, MF_MEM_PRE_REMOVE)
      -> xfs_dax_notify_failure()
      `-> freeze_super()             // freeze (kernel call)
      `-> do xfs rmap
      ` -> mf_dax_kill_procs()
      `  -> collect_procs_fsdax()    // all associated processes
      `  -> unmap_and_kill()
      ` -> invalidate_inode_pages2_range() // drop file's cache
      `-> thaw_super()               // thaw (both kernel & user call)

Introduce MF_MEM_PRE_REMOVE to let filesystem know this is a remove
event.  Use the exclusive freeze/thaw[2] to lock the filesystem to prevent
new dax mapping from being created.  Do not shutdown filesystem directly
if configuration is not supported, or if failure range includes metadata
area.  Make sure all files and processes(not only the current progress)
are handled correctly.  Also drop the cache of associated files before
pmem is removed.

[1]: https://lore.kernel.org/linux-mm/161604050314.1463742.14151665140035795571.stgit@dwillia2-desk3.amr.corp.intel.com/
[2]: https://lore.kernel.org/linux-xfs/169116275623.3187159.16862410128731457358.stg-ugh@frogsfrogsfrogs/

Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2023-12-07 14:34:26 +05:30
Matthew Wilcox (Oracle) 91e79d22be mm: convert DAX lock/unlock page to lock/unlock folio
The one caller of DAX lock/unlock page already calls compound_head(), so
use page_folio() instead, then use a folio throughout the DAX code to
remove uses of page->mapping and page->index.

[jane.chu@oracle.com: add comment to mf_generic_kill_procss(), simplify mf_generic_kill_procs:folio initialization]
  Link: https://lkml.kernel.org/r/20230908222336.186313-1-jane.chu@oracle.com
Link: https://lkml.kernel.org/r/20230822231314.349200-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Jane Chu <jane.chu@oracle.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jane Chu <jane.chu@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04 10:32:20 -07:00
Linus Torvalds 3c5c9b7cfd Seven hotfixes. Four are cc:stable and the remainder pertain to issues
which were introduced in the current merge window.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZPd5KAAKCRDdBJ7gKXxA
 jqIrAPoCqnQwOA577hJ3B1iEZnbYC0dlf5Rsk+uS/2HFnVeLhAD6A0uFOIE11ZQR
 I9AU7NDtu8NYkh9Adz+cRDeLNWbRSAo=
 =EFfq
 -----END PGP SIGNATURE-----

Merge tag 'mm-hotfixes-stable-2023-09-05-11-51' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "Seven hotfixes. Four are cc:stable and the remainder pertain to issues
  which were introduced in the current merge window"

* tag 'mm-hotfixes-stable-2023-09-05-11-51' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  sparc64: add missing initialization of folio in tlb_batch_add()
  mm: memory-failure: use rcu lock instead of tasklist_lock when collect_procs()
  revert "memfd: improve userspace warnings for missing exec-related flags".
  rcu: dump vmalloc memory info safely
  mm/vmalloc: add a safer version of find_vm_area() for debug
  tools/mm: fix undefined reference to pthread_once
  memcontrol: ensure memcg acquired by id is properly set up
2023-09-05 12:22:39 -07:00
Tong Tiangen d256d1cd8d mm: memory-failure: use rcu lock instead of tasklist_lock when collect_procs()
We found a softlock issue in our test, analyzed the logs, and found that
the relevant CPU call trace as follows:

CPU0:
  _do_fork
    -> copy_process()
      -> write_lock_irq(&tasklist_lock)  //Disable irq,waiting for
      					 //tasklist_lock

CPU1:
  wp_page_copy()
    ->pte_offset_map_lock()
      -> spin_lock(&page->ptl);        //Hold page->ptl
    -> ptep_clear_flush()
      -> flush_tlb_others() ...
        -> smp_call_function_many()
          -> arch_send_call_function_ipi_mask()
            -> csd_lock_wait()         //Waiting for other CPUs respond
	                               //IPI

CPU2:
  collect_procs_anon()
    -> read_lock(&tasklist_lock)       //Hold tasklist_lock
      ->for_each_process(tsk)
        -> page_mapped_in_vma()
          -> page_vma_mapped_walk()
	    -> map_pte()
              ->spin_lock(&page->ptl)  //Waiting for page->ptl

We can see that CPU1 waiting for CPU0 respond IPI,CPU0 waiting for CPU2
unlock tasklist_lock, CPU2 waiting for CPU1 unlock page->ptl. As a result,
softlockup is triggered.

For collect_procs_anon(), what we're doing is task list iteration, during
the iteration, with the help of call_rcu(), the task_struct object is freed
only after one or more grace periods elapse. the logic as follows:

release_task()
  -> __exit_signal()
    -> __unhash_process()
      -> list_del_rcu()

  -> put_task_struct_rcu_user()
    -> call_rcu(&task->rcu, delayed_put_task_struct)

delayed_put_task_struct()
  -> put_task_struct()
  -> if (refcount_sub_and_test())
     	__put_task_struct()
          -> free_task()

Therefore, under the protection of the rcu lock, we can safely use
get_task_struct() to ensure a safe reference to task_struct during the
iteration.

By removing the use of tasklist_lock in task list iteration, we can break
the softlock chain above.

The same logic can also be applied to:
 - collect_procs_file()
 - collect_procs_fsdax()
 - collect_procs_ksm()

Link: https://lkml.kernel.org/r/20230828022527.241693-1-tongtiangen@huawei.com
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-05 11:11:52 -07:00
Jiaqi Yan 6885938c34 mm/hwpoison: rename hwp_walk* to hwpoison_walk*
In the discussion of "Improve hugetlbfs read on HWPOISON hugepages" [1],
Matthew Wilcox suggests hwp is a bad abbreviation of hwpoison, as hwp is
already used as "an acronym by acpi, intel_pstate, some clock drivers, an
ethernet driver, and a scsi driver"[1].

So rename hwp_walk and hwp_walk_ops to hwpoison_walk and
hwpoison_walk_ops respectively.

raw_hwp_(page|list), *_raw_hwp, and raw_hwp_unreliable flag are other
major appearances of "hwp".  However, given the "raw" hint in the name, it
is easy to differentiate them from other "hwp" acronyms.  Since renaming
them is not as straightforward as renaming hwp_walk*, they are not covered
by this commit.

[1] https://lore.kernel.org/lkml/20230707201904.953262-5-jiaqiyan@google.com/T/#me6fecb8ce1ad4d5769199c9e162a44bc88f7bdec

Link: https://lkml.kernel.org/r/20230713235553.4121855-1-jiaqiyan@google.com
Signed-off-by: Jiaqi Yan <jiaqiyan@google.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-02 15:17:33 -07:00
Miaohe Lin 7a8817f2c9 mm: memory-failure: add PageOffline() check
Memory failure is not interested in logically offlined pages.  Skip this
type of page.

Link: https://lkml.kernel.org/r/20230727115643.639741-5-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-02 15:17:33 -07:00
Miaohe Lin d51b68469b mm: memory-failure: fix potential page refcnt leak in memory_failure()
put_ref_page() is not called to drop extra refcnt when comes from madvise
in the case pfn is valid but pgmap is NULL leading to page refcnt leak.

Link: https://lkml.kernel.org/r/20230701072837.1994253-1-linmiaohe@huawei.com
Fixes: 1e8aaedb18 ("mm,memory_failure: always pin the page in madvise_inject_error")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-24 16:20:16 -07:00
Andrew Morton 5994eabf3b merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes 2023-08-21 14:26:20 -07:00
Miaohe Lin 6379693e3c mm: memory-failure: use helper macro llist_for_each_entry_safe()
It's more convenient to use helper macro llist_for_each_entry_safe().
No functional change intended.

Link: https://lkml.kernel.org/r/20230807114125.3440802-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> 
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21 13:37:47 -07:00
Miaohe Lin e2c1ab070f mm: memory-failure: fix unexpected return value in soft_offline_page()
When page_handle_poison() fails to handle the hugepage or free page in
retry path, soft_offline_page() will return 0 while -EBUSY is expected in
this case.

Consequently the user will think soft_offline_page succeeds while it in
fact failed.  So the user will not try again later in this case.

Link: https://lkml.kernel.org/r/20230627112808.1275241-1-linmiaohe@huawei.com
Fixes: b94e02822d ("mm,hwpoison: try to narrow window race for free pages")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21 13:07:22 -07:00
Suren Baghdasaryan 49b0638502 mm: enable page walking API to lock vmas during the walk
walk_page_range() and friends often operate under write-locked mmap_lock. 
With introduction of vma locks, the vmas have to be locked as well during
such walks to prevent concurrent page faults in these areas.  Add an
additional member to mm_walk_ops to indicate locking requirements for the
walk.

The change ensures that page walks which prevent concurrent page faults
by write-locking mmap_lock, operate correctly after introduction of
per-vma locks.  With per-vma locks page faults can be handled under vma
lock without taking mmap_lock at all, so write locking mmap_lock would
not stop them.  The change ensures vmas are properly locked during such
walks.

A sample issue this solves is do_mbind() performing queue_pages_range()
to queue pages for migration.  Without this change a concurrent page
can be faulted into the area and be left out of migration.

Link: https://lkml.kernel.org/r/20230804152724.3090321-2-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Suggested-by: Jann Horn <jannh@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michel Lespinasse <michel@lespinasse.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21 13:07:20 -07:00
Jiaqi Yan b79f8eb408 mm/hwpoison: check if a raw page in a hugetlb folio is raw HWPOISON
Add the functionality, is_raw_hwpoison_page_in_hugepage, to tell if a raw
page in a hugetlb folio is HWPOISON.  This functionality relies on
RawHwpUnreliable to be not set; otherwise hugepage's raw HWPOISON list
becomes meaningless.

is_raw_hwpoison_page_in_hugepage holds mf_mutex in order to synchronize
with folio_set_hugetlb_hwpoison and folio_free_raw_hwp who iterate,
insert, or delete entry in raw_hwp_list.  llist itself doesn't ensure
insertion and removal are synchornized with the llist_for_each_entry used
by is_raw_hwpoison_page_in_hugepage (unless iterated entries are already
deleted from the list).  Caller can minimize the overhead of lock cycles
by first checking HWPOISON flag of the folio.

Exports this functionality to be immediately used in the read operation
for hugetlbfs.

Link: https://lkml.kernel.org/r/20230713001833.3778937-3-jiaqiyan@google.com
Signed-off-by: Jiaqi Yan <jiaqiyan@google.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18 10:12:26 -07:00
Jiaqi Yan 9e130c4b00 mm/hwpoison: delete all entries before traversal in __folio_free_raw_hwp
Patch series "Improve hugetlbfs read on HWPOISON hugepages", v4.

Today when hardware memory is corrupted in a hugetlb hugepage, kernel
leaves the hugepage in pagecache [1]; otherwise future mmap or read will
suject to silent data corruption.  This is implemented by returning -EIO
from hugetlb_read_iter immediately if the hugepage has HWPOISON flag set.

Since memory_failure already tracks the raw HWPOISON subpages in a
hugepage, a natural improvement is possible: if userspace only asks for
healthy subpages in the pagecache, kernel can return these data.

This patchset implements this improvement.  It consist of three parts. 
The 1st commit exports the functionality to tell if a subpage inside a
hugetlb hugepage is a raw HWPOISON page.  The 2nd commit teaches
hugetlbfs_read_iter to return as many healthy bytes as possible.  The 3rd
commit properly tests this new feature.

[1] commit 8625147caf ("hugetlbfs: don't delete error page from pagecache")


This patch (of 4):

Traversal on llist (e.g.  llist_for_each_safe) is only safe AFTER entries
are deleted from the llist.  Correct the way __folio_free_raw_hwp deletes
and frees raw_hwp_page entries in raw_hwp_list: first llist_del_all, then
kfree within llist_for_each_safe.

As of today, concurrent adding, deleting, and traversal on raw_hwp_list
from hugetlb.c and/or memory-failure.c are fine with each other.  Note
this is guaranteed partly by the lock-free nature of llist, and partly by
holding hugetlb_lock and/or mf_mutex.  For example, as llist_del_all is
lock-free with itself, folio_clear_hugetlb_hwpoison()s from
__update_and_free_hugetlb_folio and memory_failure won't need explicit
locking when freeing the raw_hwp_list.  New code that manipulates
raw_hwp_list must be careful to ensure the concurrency correctness.

Link: https://lkml.kernel.org/r/20230713001833.3778937-1-jiaqiyan@google.com
Link: https://lkml.kernel.org/r/20230713001833.3778937-2-jiaqiyan@google.com
Signed-off-by: Jiaqi Yan <jiaqiyan@google.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18 10:12:26 -07:00