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@pull pull bot commented May 3, 2020

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@pull pull bot added the ⤵️ pull label May 3, 2020
@pull pull bot merged commit 0e698df into ikingye:master May 3, 2020
pull bot pushed a commit that referenced this pull request Jun 26, 2020
When working with very large nodes, poisoning the struct pages (for which
there will be very many) can take a very long time.  If the system is
using voluntary preemptions, the software watchdog will not be able to
detect forward progress.  This patch addresses this issue by offering to
give up time like __remove_pages() does.  This behavior was introduced in
v5.6 with: commit d33695b ("mm/memory_hotplug: poison memmap in
remove_pfn_range_from_zone()")

Alternately, init_page_poison could do this cond_resched(), but it seems
to me that the caller of init_page_poison() is what actually knows whether
or not it should relax its own priority.

Based on Dan's notes, I think this is perfectly safe: commit f931ab4
("mm: fix devm_memremap_pages crash, use mem_hotplug_{begin, done}")

Aside from fixing the lockup, it is also a friendlier thing to do on lower
core systems that might wipe out large chunks of hotplug memory (probably
not a very common case).

Fixes this kind of splat:

  watchdog: BUG: soft lockup - CPU#46 stuck for 22s! [daxctl:9922]
  irq event stamp: 138450
  hardirqs last  enabled at (138449): [<ffffffffa1001f26>] trace_hardirqs_on_thunk+0x1a/0x1c
  hardirqs last disabled at (138450): [<ffffffffa1001f42>] trace_hardirqs_off_thunk+0x1a/0x1c
  softirqs last  enabled at (138448): [<ffffffffa1e00347>] __do_softirq+0x347/0x456
  softirqs last disabled at (138443): [<ffffffffa10c416d>] irq_exit+0x7d/0xb0
  CPU: 46 PID: 9922 Comm: daxctl Not tainted 5.7.0-BEN-14238-g373c6049b336 #30
  Hardware name: Intel Corporation PURLEY/PURLEY, BIOS PLYXCRB1.86B.0578.D07.1902280810 02/28/2019
  RIP: 0010:memset_erms+0x9/0x10
  Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01
  Call Trace:
   remove_pfn_range_from_zone+0x3a/0x380
   memunmap_pages+0x17f/0x280
   release_nodes+0x22a/0x260
   __device_release_driver+0x172/0x220
   device_driver_detach+0x3e/0xa0
   unbind_store+0x113/0x130
   kernfs_fop_write+0xdc/0x1c0
   vfs_write+0xde/0x1d0
   ksys_write+0x58/0xd0
   do_syscall_64+0x5a/0x120
   entry_SYSCALL_64_after_hwframe+0x49/0xb3
  Built 2 zonelists, mobility grouping on.  Total pages: 49050381
  Policy zone: Normal
  Built 3 zonelists, mobility grouping on.  Total pages: 49312525
  Policy zone: Normal

David said: "It really only is an issue for devmem.  Ordinary
hotplugged system memory is not affected (onlined/offlined in memory
block granularity)."

Link: http://lkml.kernel.org/r/20200619231213.1160351-1-ben.widawsky@intel.com
Fixes: commit d33695b ("mm/memory_hotplug: poison memmap in remove_pfn_range_from_zone()")
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Reported-by: "Scargall, Steve" <steve.scargall@intel.com>
Reported-by: Ben Widawsky <ben.widawsky@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
pull bot pushed a commit that referenced this pull request Aug 2, 2020
fib_trie_unmerge() is called with RTNL held, but not from an RCU
read-side critical section. This leads to the following warning [1] when
the FIB alias list in a leaf is traversed with
hlist_for_each_entry_rcu().

Since the function is always called with RTNL held and since
modification of the list is protected by RTNL, simply use
hlist_for_each_entry() and silence the warning.

[1]
WARNING: suspicious RCU usage
5.8.0-rc4-custom-01520-gc1f937f3f83b #30 Not tainted
-----------------------------
net/ipv4/fib_trie.c:1867 RCU-list traversed in non-reader section!!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by ip/164:
 #0: ffffffff85a27850 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x49a/0xbd0

stack backtrace:
CPU: 0 PID: 164 Comm: ip Not tainted 5.8.0-rc4-custom-01520-gc1f937f3f83b #30
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
 dump_stack+0x100/0x184
 lockdep_rcu_suspicious+0x153/0x15d
 fib_trie_unmerge+0x608/0xdb0
 fib_unmerge+0x44/0x360
 fib4_rule_configure+0xc8/0xad0
 fib_nl_newrule+0x37a/0x1dd0
 rtnetlink_rcv_msg+0x4f7/0xbd0
 netlink_rcv_skb+0x17a/0x480
 rtnetlink_rcv+0x22/0x30
 netlink_unicast+0x5ae/0x890
 netlink_sendmsg+0x98a/0xf40
 ____sys_sendmsg+0x879/0xa00
 ___sys_sendmsg+0x122/0x190
 __sys_sendmsg+0x103/0x1d0
 __x64_sys_sendmsg+0x7d/0xb0
 do_syscall_64+0x54/0xa0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fc80a234e97
Code: Bad RIP value.
RSP: 002b:00007ffef8b66798 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc80a234e97
RDX: 0000000000000000 RSI: 00007ffef8b66800 RDI: 0000000000000003
RBP: 000000005f141b1c R08: 0000000000000001 R09: 0000000000000000
R10: 00007fc80a2a8ac0 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 00007ffef8b67008 R15: 0000556fccb10020

Fixes: 0ddcf43 ("ipv4: FIB Local/MAIN table collapse")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
pull bot pushed a commit that referenced this pull request Aug 5, 2020
The following deadlock was captured. The first process is holding 'kernfs_mutex'
and hung by io. The io was staging in 'r1conf.pending_bio_list' of raid1 device,
this pending bio list would be flushed by second process 'md127_raid1', but
it was hung by 'kernfs_mutex'. Using sysfs_notify_dirent_safe() to replace
sysfs_notify() can fix it. There were other sysfs_notify() invoked from io
path, removed all of them.

 PID: 40430  TASK: ffff8ee9c8c65c40  CPU: 29  COMMAND: "probe_file"
  #0 [ffffb87c4df37260] __schedule at ffffffff9a8678ec
  #1 [ffffb87c4df372f8] schedule at ffffffff9a867f06
  #2 [ffffb87c4df37310] io_schedule at ffffffff9a0c73e6
  #3 [ffffb87c4df37328] __dta___xfs_iunpin_wait_3443 at ffffffffc03a4057 [xfs]
  #4 [ffffb87c4df373a0] xfs_iunpin_wait at ffffffffc03a6c79 [xfs]
  #5 [ffffb87c4df373b0] __dta_xfs_reclaim_inode_3357 at ffffffffc039a46c [xfs]
  #6 [ffffb87c4df37400] xfs_reclaim_inodes_ag at ffffffffc039a8b6 [xfs]
  #7 [ffffb87c4df37590] xfs_reclaim_inodes_nr at ffffffffc039bb33 [xfs]
  #8 [ffffb87c4df375b0] xfs_fs_free_cached_objects at ffffffffc03af0e9 [xfs]
  #9 [ffffb87c4df375c0] super_cache_scan at ffffffff9a287ec7
 #10 [ffffb87c4df37618] shrink_slab at ffffffff9a1efd93
 #11 [ffffb87c4df37700] shrink_node at ffffffff9a1f5968
 #12 [ffffb87c4df37788] do_try_to_free_pages at ffffffff9a1f5ea2
 #13 [ffffb87c4df377f0] try_to_free_mem_cgroup_pages at ffffffff9a1f6445
 #14 [ffffb87c4df37880] try_charge at ffffffff9a26cc5f
 #15 [ffffb87c4df37920] memcg_kmem_charge_memcg at ffffffff9a270f6a
 #16 [ffffb87c4df37958] new_slab at ffffffff9a251430
 #17 [ffffb87c4df379c0] ___slab_alloc at ffffffff9a251c85
 #18 [ffffb87c4df37a80] __slab_alloc at ffffffff9a25635d
 #19 [ffffb87c4df37ac0] kmem_cache_alloc at ffffffff9a251f89
 #20 [ffffb87c4df37b00] alloc_inode at ffffffff9a2a2b10
 #21 [ffffb87c4df37b20] iget_locked at ffffffff9a2a4854
 #22 [ffffb87c4df37b60] kernfs_get_inode at ffffffff9a311377
 #23 [ffffb87c4df37b80] kernfs_iop_lookup at ffffffff9a311e2b
 #24 [ffffb87c4df37ba8] lookup_slow at ffffffff9a290118
 #25 [ffffb87c4df37c10] walk_component at ffffffff9a291e83
 #26 [ffffb87c4df37c78] path_lookupat at ffffffff9a293619
 #27 [ffffb87c4df37cd8] filename_lookup at ffffffff9a2953af
 #28 [ffffb87c4df37de8] user_path_at_empty at ffffffff9a295566
 #29 [ffffb87c4df37e10] vfs_statx at ffffffff9a289787
 #30 [ffffb87c4df37e70] SYSC_newlstat at ffffffff9a289d5d
 #31 [ffffb87c4df37f18] sys_newlstat at ffffffff9a28a60e
 #32 [ffffb87c4df37f28] do_syscall_64 at ffffffff9a003949
 #33 [ffffb87c4df37f50] entry_SYSCALL_64_after_hwframe at ffffffff9aa001ad
     RIP: 00007f617a5f2905  RSP: 00007f607334f838  RFLAGS: 00000246
     RAX: ffffffffffffffda  RBX: 00007f6064044b20  RCX: 00007f617a5f2905
     RDX: 00007f6064044b20  RSI: 00007f6064044b20  RDI: 00007f6064005890
     RBP: 00007f6064044aa0   R8: 0000000000000030   R9: 000000000000011c
     R10: 0000000000000013  R11: 0000000000000246  R12: 00007f606417e6d0
     R13: 00007f6064044aa0  R14: 00007f6064044b10  R15: 00000000ffffffff
     ORIG_RAX: 0000000000000006  CS: 0033  SS: 002b

 PID: 927    TASK: ffff8f15ac5dbd80  CPU: 42  COMMAND: "md127_raid1"
  #0 [ffffb87c4df07b28] __schedule at ffffffff9a8678ec
  #1 [ffffb87c4df07bc0] schedule at ffffffff9a867f06
  #2 [ffffb87c4df07bd8] schedule_preempt_disabled at ffffffff9a86825e
  #3 [ffffb87c4df07be8] __mutex_lock at ffffffff9a869bcc
  #4 [ffffb87c4df07ca0] __mutex_lock_slowpath at ffffffff9a86a013
  #5 [ffffb87c4df07cb0] mutex_lock at ffffffff9a86a04f
  #6 [ffffb87c4df07cc8] kernfs_find_and_get_ns at ffffffff9a311d83
  #7 [ffffb87c4df07cf0] sysfs_notify at ffffffff9a314b3a
  #8 [ffffb87c4df07d18] md_update_sb at ffffffff9a688696
  #9 [ffffb87c4df07d98] md_update_sb at ffffffff9a6886d5
 #10 [ffffb87c4df07da8] md_check_recovery at ffffffff9a68ad9c
 #11 [ffffb87c4df07dd0] raid1d at ffffffffc01f0375 [raid1]
 #12 [ffffb87c4df07ea0] md_thread at ffffffff9a680348
 #13 [ffffb87c4df07f08] kthread at ffffffff9a0b8005
 #14 [ffffb87c4df07f50] ret_from_fork at ffffffff9aa00344

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
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