RHEL7:系统出现间歇性的性能降低问题

Environment

• Red Hat Enterprise Linux (RHEL) 7.4, 7.5, 7.6.
• 服务器使用 uEFI 引导，并具有 ACPI BGRT 数据(/sys/firmware/acpi/bgrt/image)
• 可以会出现类似以下的日志警告信息：

[    0.325420] ------------[ cut here ]------------
[    0.325426] WARNING: CPU: 0 PID: 0 at arch/x86/mm/ioremap.c:119 __ioremap_caller+0x279/0x320
[    0.325428] ioremap on RAM at 0xc5f51018 - 0xc5f5101d
[    0.325429] Modules linked in:
[    0.325432] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.10.0-693.el7.x86_64 #1
[    0.325433] Hardware name:  XXX
[    0.325434]  ffffffff819e7e38 24c6cdef24c6cdb8 ffffffff819e7de8 ffffffff816a3d91
[    0.325437]  ffffffff819e7e28 ffffffff810879c8 00000077c5f51fff 00000000c5f5101d
[    0.325439]  0000000000000006 00000000c5f5101e 0000000000000010 00000000c5f51018
[    0.325441] Call Trace:
[    0.325446]  [<ffffffff816a3d91>] dump_stack+0x19/0x1b
[    0.325449]  [<ffffffff810879c8>] __warn+0xd8/0x100
[    0.325451]  [<ffffffff81087a4f>] warn_slowpath_fmt+0x5f/0x80
[    0.325454]  [<ffffffff81067fe9>] __ioremap_caller+0x279/0x320
[    0.325457]  [<ffffffff813c95da>] ? acpi_tb_validate_table+0x27/0x37
[    0.325461]  [<ffffffff81b668e4>] ? efi_bgrt_init+0x6c/0x108
[    0.325463]  [<ffffffff810680a7>] ioremap_nocache+0x17/0x20
[    0.325465]  [<ffffffff81b668e4>] efi_bgrt_init+0x6c/0x108
[    0.325467]  [<ffffffff81b65d2e>] efi_late_init+0x13/0x15
[    0.325470]  [<ffffffff81b45051>] start_kernel+0x42a/0x45a
[    0.325471]  [<ffffffff81b44a30>] ? repair_env_string+0x5c/0x5c
[    0.325474]  [<ffffffff81b44120>] ? early_idt_handler_array+0x120/0x120
[    0.325476]  [<ffffffff81b445ef>] x86_64_start_reservations+0x24/0x26
[    0.325478]  [<ffffffff81b44740>] x86_64_start_kernel+0x14f/0x172
[    0.325481] ---[ end trace 25a5ba0f2a13fe13 ]---

或

Mar  6 15:54:53 localhost kernel: ------------[ cut here ]------------
Mar  6 15:54:53 localhost kernel: WARNING: CPU: 0 PID: 0 at arch/x86/mm/ioremap.c:115 __ioremap_caller+0x179/0x340
Mar  6 15:54:53 localhost kernel: ioremap on RAM at 0x86f12018 - 0x86f1201d
Mar  6 15:54:53 localhost kernel: Modules linked in:
Mar  6 15:54:53 localhost kernel: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.10.0-862.el7.x86_64 #1
Mar  6 15:54:53 localhost kernel: Hardware name: XXX
Mar  6 15:54:53 localhost kernel: Call Trace:
Mar  6 15:54:53 localhost kernel: [<ffffffff81b0d768>] dump_stack+0x19/0x1b
Mar  6 15:54:53 localhost kernel: [<ffffffff814916d8>] __warn+0xd8/0x100
Mar  6 15:54:53 localhost kernel: [<ffffffff8149175f>] warn_slowpath_fmt+0x5f/0x80
Mar  6 15:54:53 localhost kernel: [<ffffffff8146f2c9>] __ioremap_caller+0x179/0x340
Mar  6 15:54:53 localhost kernel: [<ffffffff82190243>] ? efi_bgrt_init+0x6c/0x108
Mar  6 15:54:53 localhost kernel: [<ffffffff8146f4a7>] ioremap_nocache+0x17/0x20
Mar  6 15:54:53 localhost kernel: [<ffffffff82190243>] efi_bgrt_init+0x6c/0x108
Mar  6 15:54:53 localhost kernel: [<ffffffff8218f541>] efi_late_init+0x13/0x15
Mar  6 15:54:53 localhost kernel: [<ffffffff8216c1b2>] start_kernel+0x437/0x467
Mar  6 15:54:53 localhost kernel: [<ffffffff8216bb7b>] ? repair_env_string+0x5c/0x5c
Mar  6 15:54:53 localhost kernel: [<ffffffff8216b120>] ? early_idt_handler_array+0x120/0x120
Mar  6 15:54:53 localhost kernel: [<ffffffff8216b72f>] x86_64_start_reservations+0x24/0x26
Mar  6 15:54:53 localhost kernel: [<ffffffff8216b885>] x86_64_start_kernel+0x154/0x177
Mar  6 15:54:53 localhost kernel: [<ffffffff814000d5>] start_cpu+0x5/0x14
Mar  6 15:54:53 localhost kernel: ---[ end trace b44fe2afc20dad9d ]---
Mar  6 15:54:53 localhost kernel: Ignoring BGRT: failed to map image header memory