Commit 8a907cdf0177ab40 ("mm, memcg: proportional memory.{low,min} reclaim")
broke global reclaim by kdump kernel due to NULL pointer dereference at
protection = mem_cgroup_protection(memcg);
. Please fix.
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[ 0.000000][ T0] Linux version 5.0.0-rc4-next-20190131 (root@localhost.localdomain) (gcc version 4.8.5 20150623 (Red Hat 4.8.5-36) (GCC)) #280 SMP PREEMPT Fri Feb 1 09:11:44 JST 2019
[ 0.000000][ T0] Command line: BOOT_IMAGE=/boot/vmlinuz-5.0.0-rc4-next-20190131 ro security=none sysrq_always_enabled console=ttyS0,115200n8 console=tty0 LANG=en_US.UTF-8 cgroup_no_v1=all irqpoll nr_cpus=1 reset_devices cgroup_disable=memory mce=off numa=off udev.children-max=2 panic=10 rootflags=nofail acpi_no_memhotplug transparent_hugepage=never nokaslr disable_cpu_apicid=0 elfcorehdr=867732K
(...snipped...)
[ 28.323429][ T31] BUG: unable to handle kernel NULL pointer dereference at 0000000000000180
[ 28.326592][ T31] #PF error: [normal kernel read fault]
[ 28.328538][ T31] PGD 274bd067 P4D 274bd067 PUD 276e1067 PMD 0
[ 28.330587][ T31] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[ 28.332627][ T31] CPU: 0 PID: 31 Comm: kswapd0 Not tainted 5.0.0-rc4-next-20190131 #280
[ 28.335356][ T31] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/13/2018
[ 28.338845][ T31] RIP: 0010:shrink_node_memcg+0xa1/0x4d0
[ 28.340895][ T31] Code: 49 c7 04 24 00 00 00 00 45 31 f6 49 89 dd 48 8b 44 24 28 48 8b 7c 24 18 44 89 ee 44 89 eb 0f be 50 1b e8 62 bd ff ff 48 89 c6 <49> 8b 87 80 01 00 00 49 8b 97 98 01 00 00 48 39 c2 48 0f 43 c2 48
[ 28.347084][ T31] RSP: 0018:ffffc9000011bc10 EFLAGS: 00010246
[ 28.349209][ T31] RAX: 0000000000000f8e RBX: 0000000000000000 RCX: 0000000000000003
[ 28.351858][ T31] RDX: 0000000000000004 RSI: 0000000000000f8e RDI: ffffffff822fdd68
[ 28.354750][ T31] RBP: ffffc9000011bce8 R08: 0000000000000000 R09: ffffffff822fc100
[ 28.357437][ T31] R10: 0000000000000000 R11: 0000000000000000 R12: ffffc9000011bd40
[ 28.360018][ T31] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[ 28.362825][ T31] FS: 0000000000000000(0000) GS:ffff888034800000(0000) knlGS:0000000000000000
[ 28.365961][ T31] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 28.368279][ T31] CR2: 0000000000000180 CR3: 0000000027352004 CR4: 00000000003606b0
[ 28.370939][ T31] Call Trace:
[ 28.372315][ T31] ? __lock_acquire+0x959/0x1260
[ 28.374140][ T31] shrink_node+0xd8/0x460
[ 28.375847][ T31] balance_pgdat+0x24d/0x4b0
[ 28.377636][ T31] kswapd+0x1ac/0x5e0
[ 28.379302][ T31] ? wait_woken+0xa0/0xa0
[ 28.380938][ T31] kthread+0x10b/0x140
[ 28.382516][ T31] ? balance_pgdat+0x4b0/0x4b0
[ 28.384263][ T31] ? kthread_cancel_delayed_work_sync+0x10/0x10
[ 28.386530][ T31] ret_from_fork+0x24/0x30
[ 28.388196][ T31] Modules linked in: xfs libcrc32c sd_mod sr_mod cdrom serio_raw ahci libahci mptspi ata_generic pata_acpi scsi_transport_spi mptscsih mptbase vmwgfx drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm i2c_core ata_piix libata
[ 28.395374][ T31] CR2: 0000000000000180
[ 28.397135][ T31] ---[ end trace 42d4bab7295e2355 ]---
[ 28.399381][ T31] RIP: 0010:shrink_node_memcg+0xa1/0x4d0
[ 28.401444][ T31] Code: 49 c7 04 24 00 00 00 00 45 31 f6 49 89 dd 48 8b 44 24 28 48 8b 7c 24 18 44 89 ee 44 89 eb 0f be 50 1b e8 62 bd ff ff 48 89 c6 <49> 8b 87 80 01 00 00 49 8b 97 98 01 00 00 48 39 c2 48 0f 43 c2 48
[ 28.408079][ T31] RSP: 0018:ffffc9000011bc10 EFLAGS: 00010246
[ 28.410327][ T31] RAX: 0000000000000f8e RBX: 0000000000000000 RCX: 0000000000000003
[ 28.412930][ T31] RDX: 0000000000000004 RSI: 0000000000000f8e RDI: ffffffff822fdd68
[ 28.415567][ T31] RBP: ffffc9000011bce8 R08: 0000000000000000 R09: ffffffff822fc100
[ 28.418284][ T31] R10: 0000000000000000 R11: 0000000000000000 R12: ffffc9000011bd40
[ 28.421068][ T31] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[ 28.423683][ T31] FS: 0000000000000000(0000) GS:ffff888034800000(0000) knlGS:0000000000000000
[ 28.426549][ T31] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 28.428977][ T31] CR2: 0000000000000180 CR3: 0000000027352004 CR4: 00000000003606b0
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