Kernel tainted 512 due to WARNING: at mm/page_alloc.c:3189 __alloc_pages_slowpath when loading megaraid_sas

Issue

• The kernel is tainted with value 512 every time after the megaraid_sas driver gets loaded:

[    5.735448] ------------[ cut here ]------------
[    5.735461] WARNING: CPU: 10 PID: 891 at mm/page_alloc.c:3189 __alloc_pages_slowpath+0x6f/0x724
[    5.735463] Modules linked in: ahci(+) megaraid_sas(+) libahci ptp drm_panel_orientation_quirks pps_core libata nfit libnvdimm dm_mirror dm_region_hash dm_log dm_mod
[    5.735479] CPU: 10 PID: 891 Comm: systemd-udevd Not tainted 3.10.0-957.el7.x86_64 #1
[    5.735481] Hardware name: Quanta Cloud Technology Inc. QuantaGrid D52B-1U/S5B-MB (LBG-4), BIOS 3A13.Q402 11/16/2018
[    5.735483] Call Trace:
[    5.735493]  [<ffffffff83361dc1>] dump_stack+0x19/0x1b
[    5.735501]  [<ffffffff82c97648>] __warn+0xd8/0x100
[    5.735504]  [<ffffffff82c9778d>] warn_slowpath_null+0x1d/0x20
[    5.735507]  [<ffffffff8335cd87>] __alloc_pages_slowpath+0x6f/0x724
[    5.735514]  [<ffffffff82dd8058>] ? zone_statistics+0x88/0xa0
[    5.735523]  [<ffffffff82cdc716>] ? select_task_rq_fair+0x5a6/0x760
[    5.735530]  [<ffffffff82dc0e95>] __alloc_pages_nodemask+0x405/0x420
[    5.735539]  [<ffffffff82c3217f>] dma_generic_alloc_coherent+0x8f/0x140
[    5.735547]  [<ffffffff82c6b7a1>] x86_swiotlb_alloc_coherent+0x21/0x50
[    5.735553]  [<ffffffff82e06226>] dma_pool_alloc+0x126/0x280
[    5.735563]  [<ffffffffc01cba19>] megasas_alloc_request_fusion+0xe9/0x3e0 [megaraid_sas]
[    5.735570]  [<ffffffffc01cc4b5>] megasas_alloc_cmds_fusion+0x25/0x5e0 [megaraid_sas]
[    5.735576]  [<ffffffffc01c5db0>] ? megasas_alloc_cmds+0x200/0x460 [megaraid_sas]
[    5.735584]  [<ffffffffc01cd94e>] megasas_init_adapter_fusion+0x29e/0x9a0 [megaraid_sas]
[    5.735590]  [<ffffffff830a3c1c>] ? _dev_info+0x6c/0x90
[    5.735596]  [<ffffffffc01c94a7>] megasas_init_fw+0xb97/0x1d00 [megaraid_sas]
[    5.735602]  [<ffffffffc01ca743>] megasas_probe_one+0x133/0x710 [megaraid_sas]
[    5.735610]  [<ffffffff82fc4aca>] local_pci_probe+0x4a/0xb0
[    5.735613]  [<ffffffff82fc6209>] pci_device_probe+0x109/0x160
[    5.735618]  [<ffffffff830a8285>] driver_probe_device+0xc5/0x3e0
[    5.735621]  [<ffffffff830a8683>] __driver_attach+0x93/0xa0
[    5.735624]  [<ffffffff830a85f0>] ? __device_attach+0x50/0x50
[    5.735627]  [<ffffffff830a5e25>] bus_for_each_dev+0x75/0xc0
[    5.735629] ahci 0000:00:11.5: version 3.0
[    5.735634]  [<ffffffff830a7bfe>] driver_attach+0x1e/0x20
[    5.735637]  [<ffffffff830a76a0>] bus_add_driver+0x200/0x2d0
[    5.735640]  [<ffffffff830a8d14>] driver_register+0x64/0xf0
[    5.735643]  [<ffffffff82fc5a45>] __pci_register_driver+0xa5/0xc0
[    5.735645]  [<ffffffffc01e2000>] ? 0xffffffffc01e1fff
[    5.735650]  [<ffffffffc01e20d1>] megasas_init+0xd1/0x1000 [megaraid_sas]
[    5.735658]  [<ffffffff82c0210a>] do_one_initcall+0xba/0x240
[    5.735663]  [<ffffffff82d18f8c>] load_module+0x272c/0x2bc0
[    5.735667]  [<ffffffff82fa3030>] ? ddebug_proc_write+0x100/0x100
[    5.735672]  [<ffffffff82d1950f>] SyS_init_module+0xef/0x140
[    5.735678]  [<ffffffff83374ddb>] system_call_fastpath+0x22/0x27
[    5.735690] ---[ end trace d67c5a4497eb50a5 ]---