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Используйте параметры загрузки для ограничения количества доступных процессоров.
Существует два различных параметра загрузки, которые влияют на количество доступных процессоров.
- Параметр nr_cpus, который можно использовать в качестве жесткого ограничения.
- Параметр maxcpus, который можно использовать в качестве мягкого ограничения и изменить позже по своему усмотрению.
Как правило, вы хотите использовать первый вариант, если вы ограничены какими-либо лицензионными условиями.
Предварительная информация
Я буду использовать следующую конфигурацию.
$ lscpu
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Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian Address sizes: 39 bits physical, 48 bits virtual CPU(s): 32 On-line CPU(s) list: 0-31 Thread(s) per core: 1 Core(s) per socket: 32 Socket(s): 1 NUMA node(s): 1 Vendor ID: GenuineIntel CPU family: 6 Model: 60 Model name: Intel® Core™ i5-4570S CPU @ 2.90GHz Stepping: 3 CPU MHz: 2893.298 BogoMIPS: 5786.59 Hypervisor vendor: KVM Virtualization type: full L1d cache: 1 MiB L1i cache: 1 MiB L2 cache: 8 MiB L3 cache: 192 MiB NUMA node0 CPU(s): 0-31 Vulnerability Itlb multihit: KVM: Mitigation: VMX unsupported Vulnerability L1tf: Mitigation; PTE Inversion Vulnerability Mds: Mitigation; Clear CPU buffers; SMT Host state unknown Vulnerability Meltdown: Mitigation; PTI Vulnerability Spec store bypass: Vulnerable Vulnerability Spectre v1: Mitigation; usercopy/swapgs barriers and __user pointer sanitization Vulnerability Spectre v2: Mitigation; Full generic retpoline, STIBP disabled, RSB filling Vulnerability Srbds: Unknown: Dependent on hypervisor status Vulnerability Tsx async abort: Not affected Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx rdtscp lm con stant_tsc rep_good nopl xtopology nonstop_tsc cpuid tsc_known_freq pni pclmulqdq ssse3 cx16 pcid sse4_1 sse4_2 movbe popcnt a es xsave avx rdrand hypervisor lahf_lm abm invpcid_single pti fsgsbase avx2 invpcid md_clear flush_l1d |
Жесткое ограничение
Этот метод ограничивает количество доступных процессоров до 16.
$ cat /etc/default/grub
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# If you change this file, run 'update-grub' afterwards to update # /boot/grub/grub.cfg. # For full documentation of the options in this file, see: # info -f grub -n 'Simple configuration' GRUB_DEFAULT=0 GRUB_TIMEOUT=5 GRUB_DISTRIBUTOR=`lsb_release -i -s 2 > /dev/null || echo Debian` GRUB_CMDLINE_LINUX_DEFAULT="net.ifnames=0 biosdevname=0" GRUB_CMDLINE_LINUX="consoleblank=0 <strong>nr_cpus=16</strong>" # Uncomment to enable BadRAM filtering, modify to suit your needs # This works with Linux (no patch required) and with any kernel that obtains # the memory map information from GRUB (GNU Mach, kernel of FreeBSD …) #GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef" # Uncomment to disable graphical terminal (grub-pc only) #GRUB_TERMINAL=console # The resolution used on graphical terminal # note that you can use only modes which your graphic card supports via VBE # you can see them in real GRUB with the command `vbeinfo' #GRUB_GFXMODE=640x480 # Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux #GRUB_DISABLE_LINUX_UUID=true # Uncomment to disable generation of recovery mode menu entries #GRUB_DISABLE_RECOVERY="true" # Uncomment to get a beep at grub start #GRUB_INIT_TUNE="480 440 1" |
Обновите Grub.
$ sudo update-grub
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Generating grub configuration file ... Found linux image: /boot/vmlinuz-5.10.0-6-amd64 Found initrd image: /boot/initrd.img-5.10.0-6-amd64 Found linux image: /boot/vmlinuz-5.10.0-3-amd64 Found initrd image: /boot/initrd.img-5.10.0-3-amd64 done |
Перезагрузите операционную систему.
$ sudo reboot
Отображение информации о процессорах.
$ lscpu
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 |
Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian Address sizes: 39 bits physical, 48 bits virtual <strong>CPU(s): 8 On-line CPU(s) list: 0-3 Off-line CPU(s) list: 4-7 Thread(s) per core: 1 Core(s) per socket: 4 Socket(s): 1 NUMA node(s): 1 Vendor ID: GenuineIntel CPU family: 6 Model: 60 Model name: Intel® Core™ i5-4570S CPU @ 2.90GHz Stepping: 3 CPU MHz: 2893.298 BogoMIPS: 5786.59 Hypervisor vendor: KVM Virtualization type: full L1d cache: 128 KiB L1i cache: 128 KiB L2 cache: 1 MiB L3 cache: 24 MiB NUMA node0 CPU(s): 0-3 Vulnerability Itlb multihit: KVM: Mitigation: VMX unsupported Vulnerability L1tf: Mitigation; PTE Inversion Vulnerability Mds: Mitigation; Clear CPU buffers; SMT Host state unknown Vulnerability Meltdown: Mitigation; PTI Vulnerability Spec store bypass: Vulnerable Vulnerability Spectre v1: Mitigation; usercopy/swapgs barriers and __user pointer sanitization Vulnerability Spectre v2: Mitigation; Full generic retpoline, STIBP disabled, RSB filling Vulnerability Srbds: Unknown: Dependent on hypervisor status Vulnerability Tsx async abort: Not affected Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx rdtscp lm con stant_tsc rep_good nopl xtopology nonstop_tsc cpuid tsc_known_freq pni pclmulqdq ssse3 cx16 pcid sse4_1 sse4_2 movbe popcnt a es xsave avx rdrand hypervisor lahf_lm abm invpcid_single pti fsgsbase avx2 invpcid md_clear flush_l1d |
В этом примере вы уменьшили количество процессоров с 32 до 16.
Эта опция очень полезна, когда вы ограничены лицензионными ограничениями.
Мягкое ограничение
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# If you change this file, run 'update-grub' afterwards to update # /boot/grub/grub.cfg. # For full documentation of the options in this file, see: # info -f grub -n 'Simple configuration' GRUB_DEFAULT=0 GRUB_TIMEOUT=5 GRUB_DISTRIBUTOR=`lsb_release -i -s 2>/dev/null || echo Debian` GRUB_CMDLINE_LINUX_DEFAULT="net.ifnames=0 biosdevname=0" GRUB_CMDLINE_LINUX="consoleblank=0 <strong>nr_cpus=8 maxcpus=4</strong>" # Uncomment to enable BadRAM filtering, modify to suit your needs # This works with Linux (no patch required) and with any kernel that obtains # the memory map information from GRUB (GNU Mach, kernel of FreeBSD …) #GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef" # Uncomment to disable graphical terminal (grub-pc only) #GRUB_TERMINAL=console # The resolution used on graphical terminal # note that you can use only modes which your graphic card supports via VBE # you can see them in real GRUB with the command `vbeinfo' #GRUB_GFXMODE=640x480 # Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux #GRUB_DISABLE_LINUX_UUID=true # Uncomment to disable generation of recovery mode menu entries #GRUB_DISABLE_RECOVERY="true" # Uncomment to get a beep at grub start #GRUB_INIT_TUNE="480 440 1" |
Обновите Grub.
$ sudo update-grub
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Generating grub configuration file ... Found linux image: /boot/vmlinuz-5.10.0-6-amd64 Found initrd image: /boot/initrd.img-5.10.0-6-amd64 Found linux image: /boot/vmlinuz-5.10.0-3-amd64 Found initrd image: /boot/initrd.img-5.10.0-3-amd64 done |
Перезагрузите операционную систему.
$ sudo reboot
Отображение информации о процессорах.
$ lscpu
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 |
Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian Address sizes: 39 bits physical, 48 bits virtual <strong>CPU(s): 8 On-line CPU(s) list: 0-3 Off-line CPU(s) list: 4-7 Thread(s) per core: 1 Core(s) per socket: 4 Socket(s): 1 NUMA node(s): 1 Vendor ID: GenuineIntel CPU family: 6 Model: 60 Model name: Intel® Core™ i5-4570S CPU @ 2.90GHz Stepping: 3 CPU MHz: 2893.298 BogoMIPS: 5786.59 Hypervisor vendor: KVM Virtualization type: full L1d cache: 128 KiB L1i cache: 128 KiB L2 cache: 1 MiB L3 cache: 24 MiB NUMA node0 CPU(s): 0-3 Vulnerability Itlb multihit: KVM: Mitigation: VMX unsupported Vulnerability L1tf: Mitigation; PTE Inversion Vulnerability Mds: Mitigation; Clear CPU buffers; SMT Host state unknown Vulnerability Meltdown: Mitigation; PTI Vulnerability Spec store bypass: Vulnerable Vulnerability Spectre v1: Mitigation; usercopy/swapgs barriers and __user pointer sanitization Vulnerability Spectre v2: Mitigation; Full generic retpoline, STIBP disabled, RSB filling Vulnerability Srbds: Unknown: Dependent on hypervisor status Vulnerability Tsx async abort: Not affected Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx rdtscp lm con stant_tsc rep_good nopl xtopology nonstop_tsc cpuid tsc_known_freq pni pclmulqdq ssse3 cx16 pcid sse4_1 sse4_2 movbe popcnt a es xsave avx rdrand hypervisor lahf_lm abm invpcid_single pti fsgsbase avx2 invpcid md_clear flush_l1d |
На этот раз вы с 32 процессоров спустились до 8 доступных процессоров, но только 4 онлайн.
$ find /sys/devices/system/cpu/cpu?/online -exec bash -c "echo -n '{}: '; cat {}" \;
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/sys/devices/system/cpu/cpu1/online: 1 /sys/devices/system/cpu/cpu2/online: 1 /sys/devices/system/cpu/cpu3/online: 1 /sys/devices/system/cpu/cpu4/online: 0 /sys/devices/system/cpu/cpu5/online: 0 /sys/devices/system/cpu/cpu6/online: 0 /sys/devices/system/cpu/cpu7/online: 0 |
Обратите внимание, вы не можете отключить cpu0.
Вы можете включить (1) или выключить (0) эти процессоры.
Note, you cannot disable cpu0.
You can enable (1) or disable (0) these processors.
$ echo 1 | sudo tee /sys/devices/system/cpu/cpu6/online
$ lscpu
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Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian Address sizes: 39 bits physical, 48 bits virtual <strong>CPU(s): 8 On-line CPU(s) list: 0-3,6 Off-line CPU(s) list: 4,5,7 Thread(s) per core: 1 Core(s) per socket: 5 Socket(s): 1 NUMA node(s): 1 Vendor ID: GenuineIntel CPU family: 6 Model: 60 Model name: Intel® Core™ i5-4570S CPU @ 2.90GHz Stepping: 3 CPU MHz: 2893.298 BogoMIPS: 5786.59 Hypervisor vendor: KVM Virtualization type: full L1d cache: 160 KiB L1i cache: 160 KiB L2 cache: 1.3 MiB L3 cache: 30 MiB NUMA node0 CPU(s): 0-3,6 Vulnerability Itlb multihit: KVM: Mitigation: VMX unsupported Vulnerability L1tf: Mitigation; PTE Inversion Vulnerability Mds: Mitigation; Clear CPU buffers; SMT Host state unknown Vulnerability Meltdown: Mitigation; PTI Vulnerability Spec store bypass: Vulnerable Vulnerability Spectre v1: Mitigation; usercopy/swapgs barriers and __user pointer sanitization Vulnerability Spectre v2: Mitigation; Full generic retpoline, STIBP disabled, RSB filling Vulnerability Srbds: Unknown: Dependent on hypervisor status Vulnerability Tsx async abort: Not affected Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx rdtscp lm con stant_tsc rep_good nopl xtopology nonstop_tsc cpuid tsc_known_freq pni pclmulqdq ssse3 cx16 pcid sse4_1 sse4_2 movbe popcnt a es xsave avx rdrand hypervisor lahf_lm abm invpcid_single pti fsgsbase avx2 invpcid md_clear flush_l1d |
Дополнительные примечания
Более подробную информацию смотрите в разделе Параметры командной строки ядра.
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nr_cpus= [SMP] Maximum number of processors that an SMP kernel could support. nr_cpus=n : n >= 1 limits the kernel to support 'n' processors. It could be larger than the number of already plugged CPU during bootup, later in runtime you can physically add extra cpu until it reaches n. So during boot up some boot time memory for per-cpu variables need be pre-allocated for later physical cpu hot plugging. |
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maxcpus= [SMP] Maximum number of processors that an SMP kernel will bring up during bootup. maxcpus=n : n >= 0 limits the kernel to bring up 'n' processors. Surely after bootup you can bring up the other plugged cpu by executing "echo 1 > /sys/devices/system/cpu/cpuX/online". So maxcpus only takes effect during system bootup. While n=0 is a special case, it is equivalent to "nosmp", which also disables the IO APIC. |
Проверьте параметры загрузки.
$ cat /proc/cmdline
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BOOT_IMAGE=/boot/vmlinuz-5.10.0-6-amd64 root=UUID=1f09a8a9-d1d4-444e-aac9-61a1af04f221 ro consoleblank=0 nr_cpus=8 maxcpus=4 elevator=noop scsi_mod.use_blk_mq=Y net.ifnames=0 biosdevname=0 |