作者：Ken Wu
Email: ken.wug@gmail.com
转载本文档请注明原文链接 http://kenwublog.com/docs/linux-kernel-2-6-31-optimization.htm！
介绍
本文档是一篇关于Linux Kernel 2.6.31的最简优化指南。作者旨在编译一份性能最佳且适合普通Application/Server开发用的内核。(非生产环境)
本文提及的内核调优，主要是通过选择最佳编译选项，删除无用驱动，减少内核尺寸，关闭部分安全特性等方式来进行的。
优化后的效果，主要体现在OS启动时间，启动后的内存占用以及应用程序运行性能。
由于作者水平有限，如果描述错误，还请不吝指教。
运行环境
|
虚拟机 |
Virtualbox 3.1.4 |
|
CPU |
Core 2 Duo P9500 2.53G 双核 开启 vt-x, APIC |
|
磁盘 |
虚拟 10G的SATA磁盘 |
|
内存 |
分了1G物理内存 |
|
网卡 |
虚拟 AMD PCNet32 100M |
|
其他 |
USB，串口，显卡，声卡全关 |
作者是在虚拟机中编译的内核，如果你与作者的运行环境不同，则本文档中的部分描述可能会与你的实际情况有一定出入。
不过，相信大部分用户在看到选项释义时，能做出适合自己的选择。
说明
下列选项中，通过 "// " 注释的行，代表金国步写的内核选项简介中未提及的选项释义。
通过红色 "<===" 注释的行，代表内核默认开启，本文档推荐关闭的选项，释义部分会给出关闭的理由。
参考资料
优化前后性能对比
|
项目 |
优化前 |
优化后 |
|
内核尺寸 |
4.1M |
1.6M |
|
启动时间（含dhcp+默认init service） |
22s |
14s |
|
启动后的内存占用 |
25M |
22M |
|
APP SPEC测试成绩 |
待测 |
待测 |
General setup --->
[ ] Prompt for development and/or incomplete code/drivers <=== 显示尚在开发中或尚未完成的代码和驱动. 我不是内核或驱动开发人员。
() Local version - append to kernel release
[ ] Automatically append version information to the version string
Kernel compression mode (Bzip2) ---> <=== 对比默认的Gzip，Bzip2拥有更高的压缩比
[*] Support for paging of anonymous memory (swap)
[*] System V IPC
[*] BSD Process Accounting
[ ] BSD Process Accounting version 3 file format
[ ] Export task/process statistics through netlink (EXPERIMENTAL) <=== 体验类选项一律关
[ ] Auditing support <=== 给SELinux提供支持。我的使用场景主要是开发应用程序，不需要那么高的安全性，另外安全总是以牺牲性能为代价
RCU Subsystem ---> // 非对称读写锁系统 是一种新的kernel锁机制，适用于读多写少环境
RCU Implementation (Classic RCU) ---> <=== 选择标准的RCU系统， tree-base是给拥有大规模CPU集群的SMP系统用的
< > Kernel .config support
(18) Kernel log buffer size (16 => 64KB, 17 => 128KB)
[] Control Group support ---><=== cgroups支持，文档资料，cgroups主要作用是给进程分组，并可以动态调控进程组的CPU占用率。比如A进程分到apple组，给予20%CPU占用率，E进程分easy组，给予50%CPU占用率，最高100%。我目前没有此类应用场景，用到时会选择将其编译进去。
[] Kernel->user space relay support (formerly relayfs) <=== 在某些文件系统上(比如debugfs)提供从内核空间向用户空间传递大量数据的接口，我目前没有此类应用场景
-*- Namespaces support
[] UTS namespace <=== 我没有已安装的应用程序要用到 UTS ns
[] IPC namespace <=== 我没有已安装的应用程序要用到 IPC ns
[] Initial RAM filesystem and RAM disk (initramfs/initrd) support <=== 用于在真正内核装载前，做一些操作（俗称两阶段启动），比如加载module，mount一些非root分区，提供灾难恢复shell环境等，资料，我是期望直接从kernel image直接启动，所以没选它
[*] Optimize for size
[ ] Configure standard kernel features (for small systems) --->
-*- Load all symbols for debugging/ksymoops
[ ] Do an extra kallsyms pass <=== 除非你在kallsyms中发现了bug并需要报告这个bug才打开该选项
Performance Counters --->
[*] Kernel Performance Counters // CPU 性能监听器，包括 CPU同一时间执行指令数，cache miss数，分支预测失败次数(Branch misprediction)。调优其他程序时或许会用到，比如JVM
[ ] Strip assembler-generated symbols during link
[ ] Disable heap randomization
Choose SLAB allocator (SLUB (Unqueued Allocator)) --->
[ ] Profiling support (EXPERIMENTAL) <=== 我不是内核开发人员，不需要profile内核
[] Activate markers <=== 一种运行时状态分析诊断工具，类似 instrumentation，资料，我用不到
[ ] Kprobes <=== 我不是内核开发人员，不需要调试内核
GCOV-based kernel profiling --->
[ ] Enable gcov-based kernel profiling
[*] Enable loadable module support ---> // 我很少使用dynamic module loading，所以，下面的选项只留一个unloading即可（默认）
--- Enable loadable module support
[ ] Forced module loading
[*] Module unloading
[ ] Module versioning support
[ ] Source checksum for all modules
-*- Enable the block layer --->
--- Enable the block layer
[*] Support for large (2TB+) block devices and files // 大硬盘支持，SATA设备如果不选，会发生 kernel panic，具体原因未知
[ ] Block layer SG support v4 <=== 支持通用scsi块设备第4版，我用的是SATA
[ ] Block layer data integrity support
IO Schedulers ---> // IO调度器支持，不同程序可以会选用不同的调度策略，这里我们不要动他
<*> Anticipatory I/O scheduler
<*> Deadline I/O scheduler
<*> CFQ I/O scheduler
Default I/O scheduler (CFQ) --->
Processor type and features --->
[*] Tickless System (Dynamic Ticks) // CPU节能，动态时间片意思是当CPU处于空闲时，降低内核定时器的轮询频率
[*] High Resolution Timer Support // 我有的时候要测试 Real Time JVM，希望内核能支持这种高响应速度的内核定时器，一般用户可关闭
[*] Symmetric multi-processing support
[ ] Support sparse irq numbering <=== 如果你想支持大量CPU，又想使用较低的内核内存占用，请启用它。我只有单块CPU
[*] Enable MPS table // 让多核/多CPU系统支持ACPI
[ ] Support for big SMP systems with more than 8 CPUs
[ ] Support for extended (non-PC) x86 platforms <=== 我是X86平台，不需要再支持其他平台
[*] Single-depth WCHAN output // 跟 proc 相关的最好不要关
[ ] Paravirtualized guest support --->
--- Paravirtualized guest support
[ ] Memtest
Processor family (Core 2/newer Xeon) ---> <=== 这里请选择对应的CPU，我是 core 2 duo
[ ] Generic x86 support <=== 通用x86支持, 如果你的CPU能够在上述"Processor family"中找到就别选了
[*] HPET Timer Support
(4) Maximum number of CPUs <=== 我的CPU是双核，算上超线程HT最多虚拟4颗逻辑CPU，所以我选4 ，默认是8
[*] SMT (Hyperthreading) scheduler support
[*] Multi-core scheduler support
Preemption Model (Voluntary Kernel Preemption (Server)) ---> <=== 这里我选择了Server，它最贴近我的使用场景
[*] Reroute for broken boot IRQs // 防止同时收到多个boot IRQ(中断)时，系统混乱
[*] Machine Check Exception
[ ] Use legacy machine check code (will go away)
[*] Intel MCE features
[ ] AMD MCE features <=== 我是intel CPU
[ ] Support for old Pentium 5 / WinChip machine checks
< > Machine check injector support
< > Toshiba Laptop support
< > Dell laptop support
[ ] Enable X86 board specific fixups for reboot <=== 修正某些旧x86主板的重起bug,这种主板基本绝种了
<*> /dev/cpu/microcode - microcode support
[*] Intel microcode patch loading support
[ ] AMD microcode patch loading support <=== 我是intel CPU
<*> /dev/cpu/*/msr - Model-specific register support
<*> /dev/cpu/*/cpuid - CPU information support
< > /sys/kernel/debug/x86/cpu/* - CPU Debug support
High Memory Support (4GB) --->
(4096) Low address space to protect from user allocation
[*] Allocate 3rd-level pagetables from highmem <=== 在内存很多(大于4G)的机器上将用户空间的页表放到高位内存区,以节约宝贵的低端内存 ，我只虚拟了1G
[ ] Check for low memory corruption <=== 低位内存脏数据检查，默认是每60秒检查一次。一般这种脏数据是因某些Bios处理不当引起的。资料链接。我信任我目前的虚拟bios版本
[] Reserve low 64K of RAM on AMI/Phoenix BIOSen <=== 我不是 AMI/Phoenix BIOS
[ ] Math emulation
[ ] MTRR (Memory Type Range Register) support <=== 我没用 X windows
[ ] MTRR cleanup support
[ ] x86 PAT support <=== 我没用 X windows
[ ] EFI runtime service support <=== 我机器是BIOS引导的，用不到EFI(Extensible Firmware Interface)，如果你有兴趣体验EFI，可以在Virtualbox中开启
[] Enable seccomp to safely compute untrusted bytecode <=== 只有嵌入式系统可以不选
[ ] Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)
Timer frequency (300 HZ) ---> <=== Server场景建议设为300hz，减少内核事件响应速度，提高程序吞吐量，桌面场景可以保持不变
[ ] kexec system call <=== 我没有运行时替换内核的需求
[ ] kernel crash dumps <=== 内核崩溃时，dump运行时信息。就算crash了，我也不会去调试内核的core dump
[ ] Build a relocatable kernel <=== 官方说明 （建立一个移动的内核，并增加10%的内核尺寸，运行时会被丢弃），我认为没实质性的作用
(0x1000000) Physical address where the kernel is loaded
[] Support for hot-pluggable CPUs <=== 热拔插CPU，我用不到
[ ] Compat VDSO support
[ ] Built-in kernel command line
Power management and ACPI options --->
[*] Power Management support
[ ] Power Management Debug Support <=== 不想调试ACPI
[ ] Verbose Power Management debugging
[ ] Suspend to RAM and standby <=== 我是用来跑server，一般不需要待机
[ ] Hibernation (aka 'suspend to disk') <=== 我是用来跑server，一般不需要休眠
[*] ACPI (Advanced Configuration and Power Interface) Support --->
[*] Deprecated /proc/acpi files
[*] Deprecated power /proc/acpi directories
[*] Future power /sys interface
[*] Deprecated /proc/acpi/event support
< > AC Adapter <=== 我不需要从AC与Battery之间做切换
< > Battery <=== 没有电池
< > Button <=== 没有Fn快捷键
-*- Video
<*> Fan
<*> Processor
<*> Thermal Zone
(0) Disable ACPI for systems before Jan 1st this year
[ ] Debug Statements
< > PCI slot detection driver
< > Smart Battery System
CPU Frequency scaling --->
[*] CPU Frequency scaling
[ ] Enable CPUfreq debugging <=== 我不需要调试 CPUfreq
< > CPU frequency translation statistics
Default CPUFreq governor (performance) ---> <=== 默认用 performance高性能的CPU调频方式
<*> 'performance' governor
< > 'powersave' governor
<> 'userspace' governor for userspace frequency scaling <=== 既允许手动调整cpu频率,也允许用户空间的程序动态的调整cpu频率(需要额外的调频软件,比如cpufreqd) 我只用 performance
<> 'ondemand' cpufreq policy governor <=== "周期性的考察CPU负载并自动的动态调整cpu频率"，我只用 performance
<> 'conservative' cpufreq governor
*** CPUFreq processor drivers ***
<*> ACPI Processor P-States driver
< > AMD Mobile K6-2/K6-3 PowerNow!
< > AMD Mobile Athlon/Duron PowerNow!
< > AMD Opteron/Athlon64 PowerNow!
< > Cyrix MediaGX/NatSemi Geode Suspend Modulation
< > Intel Enhanced SpeedStep (deprecated)
< > Intel Speedstep on ICH-M chipsets (ioport interface)
< > Intel Pentium 4 clock modulation
< > Transmeta LongRun
< > VIA Cyrix III Longhaul
Bus options (PCI etc.) --->
[*] PCI support
PCI access mode (Any) --->
[*] PCI Express support
[*] Root Port Advanced Error Reporting support // 硬件驱动会负责发送错误信息
[ ] PCI Express ECRC settings control
< > PCIE AER error injector support
[*] Message Signaled Interrupts (MSI and MSI-X)
[ ] Enable deprecated pci_find_* API
[ ] PCI Debugging
< > PCI Stub driver
[*] Interrupts on hypertransport devices
[ ] PCI IOV support
[ ] ISA support
[ ] MCA support
< > NatSemi SCx200 support
[ ] One Laptop Per Child support
< > PCCard (PCMCIA/CardBus) support ---> <=== 一般笔记本电脑会配备PCCard接口(无线网卡之类的)，看你的硬件和使用场景吧。虽然我也是NB，但我从来不用PCMCIA
< > Support for PCI Hotplug ---> <=== 我没有要热拔插PCI设备的需求
Executable file formats / Emulations --->
[*] Kernel support for ELF binaries
[*] Write ELF core dumps with partial segments
< > Kernel support for a.out and ECOFF binaries
<*> Kernel support for MISC binaries
[*] Networking support --->
Networking options --->
<*> Packet socket
[*] Packet socket: mmapped IO
<*> Unix domain sockets
<*> Transformation user configuration interface
< > PF_KEY sockets
[*] TCP/IP networking
[*] IP: multicasting
[*] IP: advanced router
Choose IP: FIB lookup algorithm (choose FIB_HASH if unsure) (FIB_HASH) --->
[*] IP: policy routing
[*] IP: equal cost multipath
[*] IP: verbose route monitoring
[ ] IP: kernel level autoconfiguration <=== 我很少用网络引导OS，内核级别的网络配置对我无用。
[ ] IP: DHCP support
[ ] IP: BOOTP support
[ ] IP: RARP support
< > IP: tunneling
< > IP: GRE tunnels over IP
[*] IP: multicast routing
[*] IP: PIM-SM version 1 support
[*] IP: PIM-SM version 2 support
[ ] IP: ARP daemon support
[ ] IP: TCP syncookie support (disabled per default) <=== 抵抗SYN flood攻击，我是开发机，暂不考虑安全特性
< > IP: AH transformation
< > IP: ESP transformation
< > IP: IPComp transformation
< > IP: IPsec transport mode
< > IP: IPsec tunnel mode
< > IP: IPsec BEET mode
[*] Large Receive Offload (ipv4/tcp)
< > INET: socket monitoring interface
[ ] TCP: advanced congestion control ---> <=== 高级拥塞控制,如果没有特殊需求(比如无线网络)就别选了
< > The IPv6 protocol ---> <=== 我暂时没有要支持IPV6的需求
[ ] NetLabel subsystem support <=== NetLabel子系统, 为诸如CIPSO与RIPSO之类能够在分组信息上添加标签的协议提供支持，我用不到
[ ] Security Marking <=== 对网络包进行安全标记,类似于nfmark,但主要是为安全目的而设计, 安全特性，我暂时不考虑
[ ] Network packet filtering framework (Netfilter) ---> <=== 我不打算使用防火墙，要用到时再编译进去
< > Asynchronous Transfer Mode (ATM)
< > 802.1d Ethernet Bridging
< > 802.1Q VLAN Support
< > DECnet Support
< > ANSI/IEEE 802.2 LLC type 2 Support
< > The IPX protocol
< > Appletalk protocol support
< > Phonet protocols family
[ ] QoS and/or fair queueing ---> <=== 通过IPRoute切换网络设备上的Qos策略，我不打算使用IP路由
[ ] Data Center Bridging support
Network testing --->
[ ] Amateur Radio support ---> <=== 我没有无线电
< > CAN bus subsystem support --->
< > IrDA (infrared) subsystem support --->
< > Bluetooth subsystem support --->
[ ] Wireless ---> <=== 我没有使用无线网卡
< > RF switch subsystem support ---> <=== 我没有RF切换设备
Device Drivers --->
Generic Driver Options --->
(/sbin/hotplug) path to uevent helper
[*] Prevent firmware from being built
-*- Userspace firmware loading support
[*] Include in-kernel firmware blobs in kernel binary
() External firmware blobs to build into the kernel binary
[ ] Driver Core verbose debug messages
[ ] Managed device resources verbose debug messages <=== 管理设备资源的冗长调试信息，我不需要
<*> Connector - unified userspace <-> kernelspace linker --->// 内核空间与用户空间的信道
[*] Report process events to userspace // 报告处理时间给用户空间
< > Memory Technology Device (MTD) support --->
< > Parallel port support --->
-*- Plug and Play support --->
[ ] PNP debugging messages <=== 调试信息，老规矩
[ ] Block devices ---> <=== 我没有想要支持的块设备，比如ramdisk, 磁盘阵列，CD/DVD刻录等，详见内部选项
[ ] Misc devices ---> <=== 没有需要支持的杂项设备
< > ATA/ATAPI/MFM/RLL support --->
SCSI device support --->
< > RAID Transport Class
-*- SCSI device support
[] legacy /proc/scsi/ support <=== 我没有SCSI设备
*** SCSI support type (disk, tape, CD-ROM) ***
<*> SCSI disk support // 就算你用SATA，此选项也必选
< > SCSI tape support
< > SCSI OnStream SC-x0 tape support
<> SCSI CDROM support <=== 我没有SCSI设备
<> SCSI generic support <=== 我没有SCSI设备
< > SCSI media changer support
[ ] Probe all LUNs on each SCSI device
[] Verbose SCSI error reporting (kernel size +=12K) <=== 我没有SCSI设备
[ ] SCSI logging facility
[ ] Asynchronous SCSI scanning
SCSI Transports --->
<> Parallel SCSI (SPI) Transport Attributes <=== 我没有SCSI设备
< > FiberChannel Transport Attributes
< > iSCSI Transport Attributes
< > SAS Domain Transport Attributes
< > SRP Transport Attributes
[ ] SCSI low-level drivers --->
< > SCSI Device Handlers --->
< > OSD-Initiator library
Serial ATA (prod) and Parallel ATA (experimental) drivers --->
[*] ATA ACPI Support
[ ] SATA Port Multiplier support <=== 我只有一枚SATA设备，没有使用 多路SATA/SATA Hub 的需求。Port Multiplier是南桥芯片提供的一种支持多块SATA设备，并共享总带宽的技术。
<*> AHCI SATA support
< > Silicon Image 3124/3132 SATA support
[*] ATA SFF support
< > ServerWorks Frodo / Apple K2 SATA support
<*> Intel ESB, ICH, PIIX3, PIIX4 PATA/SATA support // Intel ICH，G系列chipset driver
< > Marvell SATA support
< > NVIDIA SATA support
< > Pacific Digital ADMA support
< > Pacific Digital SATA QStor support
< > Promise SATA TX2/TX4 support
< > Silicon Image SATA support
< > SiS 964/965/966/180 SATA support
< > ULi Electronics SATA support
< > VIA SATA support
< > VITESSE VSC-7174 / INTEL 31244 SATA support
< > Initio 162x SATA support
< > ACPI firmware driver for PATA
< > ALi PATA support
< > AMD/NVidia PATA support <=== 我用的是SATA，取消PATA支持
< > ARTOP 6210/6260 PATA support
< > ATI PATA support
< > CMD64x PATA support
< > CS5510/5520 PATA support
< > CS5530 PATA support
< > CS5536 PATA support
< > EFAR SLC90E66 support
< > Generic ATA support
< > HPT 366/368 PATA support
< > HPT 343/363 PATA support
< > IT8211/2 PATA support
< > JMicron PATA support
< > Compaq Triflex PATA support
< > Marvell PATA support via legacy mode
<> Intel PATA MPIIX support <=== 我用的是SATA，取消PATA支持
< > Intel PATA old PIIX support <=== 我用的是SATA，取消PATA支持
< > NETCELL Revolution RAID support
< > Nat Semi NS87410 PATA support
< > Nat Semi NS87415 PATA support
< > Older Promise PATA controller support
< > PC Tech RZ1000 PATA support
< > SC1200 PATA support
< > SERVERWORKS OSB4/CSB5/CSB6/HT1000 PATA support
< > Promise PATA 2027x support
< > CMD / Silicon Image 680 PATA support
< > SiS PATA support
< > VIA PATA support
< > Winbond SL82C105 PATA support
< > Intel SCH PATA support <=== 我用的是SATA，取消PATA支持
[ ] Multiple devices driver support (RAID and LVM) ---> <=== 暂时没有要使用Raid（磁盘阵列）和LVM（逻辑卷管理器，添加，删除逻辑分区）的需求
[ ] Fusion MPT device support --->
IEEE 1394 (FireWire) support --->
< > I2O device support --->
[ ] Macintosh device drivers ---> <=== Mac系统硬件设备驱动，没什么好说的，关
[*] Network device support --->
< > Dummy net driver support
< > Bonding driver support
< > EQL (serial line load balancing) support
< > Universal TUN/TAP device driver support
< > Virtual ethernet pair device
< > General Instruments Surfboard 1000
< > ARCnet support --->
<> PHY Device support and infrastructure ---> <=== PHY (物理层控制芯片) ，里面没有我对应的硬件
[*] Ethernet (10 or 100Mbit) --->
-*- Generic Media Independent Interface device support
< > Sun Happy Meal 10/100baseT support
< > Sun GEM support
< > Sun Cassini support
[ ] 3COM cards <=== 我不是3COM网卡
[] "Tulip" family network device support ---> <=== 不是 Tulip 系列
< > HP 10/100VG PCLAN (ISA, EISA, PCI) support
[*] EISA, VLB, PCI and on board controllers
<*> AMD PCnet32 PCI support // 这是我的网卡驱动
< > AMD 8111 (new PCI lance) support
< > Adaptec Starfire/DuraLAN support
< > Broadcom 440x/47xx ethernet support
< > nForce Ethernet support <=== 不是 nForce 网卡
< > Intel(R) PRO/100+ support <=== 不是 Intel 网卡
< > Myson MTD-8xx PCI Ethernet support
< > National Semiconductor DP8381x series PCI Ethernet support
<> PCI NE2000 and clones support (see help) <=== 与NE2000无关
<> RealTek RTL-8129/8130/8139 PCI Fast Ethernet Adapter support <=== 不是 RealTek 网卡
[ ] Use PIO instead of MMIO
[ ] Support for uncommon RTL-8139 rev. K (automatic channel equalization)
[ ] Support for older RTL-8129/8130 boards
[ ] Use older RX-reset method
< > RDC R6040 Fast Ethernet Adapter support
< > SiS 900/7016 PCI Fast Ethernet Adapter support
< > SMC EtherPower II
< > SMSC LAN9420 PCI ethernet adapter support
< > Sundance Alta support
< > TI ThunderLAN support
< > Micrel KSZ8842
< > VIA Rhine support
< > Atheros L2 Fast Ethernet support
[] Ethernet (1000 Mbit) ---> <=== 如果你是千M卡，请自行选择
[] Ethernet (10000 Mbit) ---> <=== 如果你是万M卡，请自行选择
<> Token Ring driver support ---> <=== IBM的令牌环网，用以太网的忽略
Wireless LAN --->
*** Enable WiMAX (Networking options) to see the WiMAX drivers ***
USB Network Adapters --->
[ ] Wan interfaces support --->
<> FDDI driver support <=== 光纤卡驱动，相信没几个人能用上这玩意
< > PPP (point-to-point protocol) support
< > SLIP (serial line) support
[ ] Fibre Channel driver support
[ ] ISDN support --->
< > Telephony support --->
Input device support --->
-*- Generic input layer (needed for keyboard, mouse, ...)
-*- Support for memoryless force-feedback devices
<> Polled input device skeleton <=== 一种周期性轮询硬件状态的驱动，去掉后没什么副作用
*** Userland interfaces ***
-*- Mouse interface
[ ] Provide legacy /dev/psaux device
(1024) Horizontal screen resolution
(768) Vertical screen resolution
< > Joystick interface
<> Event interface <=== 将输入设备的事件存储到/dev/input/eventX供应用程序读取，没相关需求
< > Event debugging
*** Input Device Drivers ***
-*- Keyboards --->
[] Mice ---> <=== 我是用纯字符终端，如果你想用X window，请自行选择
[] Joysticks/Gamepads ---> <=== 游戏设备
[] Tablets ---> <=== 平板PC
[] Touchscreens ---> <=== 触摸屏
[] Miscellaneous devices ---> <=== 杂七杂八的驱动，扬声器，笔记本扩展按键等
Hardware I/O ports --->
Character devices --->
-*- Virtual terminal
[] Support for binding and unbinding console drivers // 在某些系统上可以使用多个控制台驱动程序(如framebuffer控制台驱动程序),该选项使得你可以选择其中之一 ，我一般只用默认的虚拟终端
[] /dev/kmem virtual device support <=== 支持/dev/kmem设备，很少用
[] Non-standard serial port support <=== 我没有非标准的串口设备
Serial drivers --->
< > 8250/16550 and compatible serial support <=== 兼容一些老式的串口设备，我一般不用
*** Non-8250 serial port support ***
< > Digi International NEO PCI Support
-*- Unix98 PTY support
[ ] Support multiple instances of devpts
[ ] Legacy (BSD) PTY support
< > IPMI top-level message handler --->
<*> Hardware Random Number Generator Core support
< > Timer IOMEM HW Random Number Generator support
<*> Intel HW Random Number Generator support
<> AMD HW Random Number Generator support <=== 我是intel主板
< > AMD Geode HW Random Number Generator support <=== 我是intel主板
<> VIA HW Random Number Generator support <=== 我是intel主板
<> /dev/nvram support <=== 直接存取CMOS，太危险，关
< > Siemens R3964 line discipline
< > Applicom intelligent fieldbus card support
< > ACP Modem (Mwave) support
< > NatSemi PC8736x GPIO Support
< > NatSemi Base GPIO Support
< > AMD CS5535/CS5536 GPIO (Geode Companion Device)
< > RAW driver (/dev/raw/rawN)
[*] HPET - High Precision Event Timer
[ ] Allow mmap of HPET
< > Hangcheck timer
-*- I2C support ---> // 感知硬件状态，比如温度，风扇转速
[ ] SPI support --->
PPS support --->
[ ] GPIO Support --->
< > Dallas's 1-wire support --->
-*- Power supply class support --->
<*> Hardware Monitoring support --->
-*- Generic Thermal sysfs driver --->
[*] Watchdog Timer Support --->
Sonics Silicon Backplane --->
Multifunction device drivers --->
[ ] Voltage and Current Regulator Support --->
< > Multimedia support --->
Graphics support --->
<> /dev/agpgart (AGP Support) ---> <=== 用字符终端的忽略
<> Direct Rendering Manager (XFree86 4.1.0 and higher DRI support) ---> <=== 用字符终端的忽略
<> Lowlevel video output switch controls <=== 用字符终端的忽略
<> Support for frame buffer devices ---> <=== 用字符终端的忽略
[] Backlight & LCD device support ---> <=== 用字符终端的忽略
Display device support --->
Console display driver support --->
[*] Enable Scrollback Buffer in System RAM
(64) Scrollback Buffer Size (in KB)
<> Sound card support ---> <=== 用不到声卡
[] HID Devices ---> <=== 用不到人力工程学设备
[] USB support ---> <=== 这个选项，对于跑物理机建议开启，因为有可能你的键盘是USB的，我是跑虚拟机的，所以关了
< > MMC/SD/SDIO card support --->
< > Sony MemoryStick card support (EXPERIMENTAL) --->
[] LED Support ---> <=== 发光二级管，应该是跟显示器相关的驱动，由于我运行的是虚拟机，所以我选择关闭
[ ] Accessibility support --->
< > InfiniBand support --->
[*] EDAC (Error Detection And Correction) reporting ---> // 硬件故障repoting
<*> Real Time Clock --->
[*] DMA Engine support --->
[ ] Auxiliary Display support --->
< > Userspace I/O drivers --->
TI VLYNQ --->
[ ] Staging drivers --->
[] X86 Platform Specific Device Drivers ---> <=== 一些笔记本的驱动，我没有相关设备
Firmware Drivers --->
< > BIOS Enhanced Disk Drive calls determine boot disk
< > BIOS update support for DELL systems via sysfs
< > Dell Systems Management Base Driver
[*] Export DMI identification via sysfs to userspace // 将BIOS里的DMI区信息导出到用户空间，部分系统管理工具可能会用到
[ ] iSCSI Boot Firmware Table Attributes
File systems --->
< > Second extended fs support
<> Ext3 journalling file system support <=== 我使用的是ext4 FS
<*> The Extended 4 (ext4) filesystem
[ ] Enable ext4dev compatibility
[*] Ext4 extended attributes
[*] Ext4 POSIX Access Control Lists
[] Ext4 Security Labels <=== 取消 SELinux 支持
[ ] JBD (ext3) debugging support
[ ] JBD2 (ext4) debugging support
< > Reiserfs support
< > JFS filesystem support
< > XFS filesystem support
< > OCFS2 file system support
[*] Dnotify support
[*] Inotify file change notification support
[*] Inotify support for userspace
[] Quota support <=== 磁盘配额支持,限制某个用户或者某组用户的磁盘占用空间，暂时没这个需求，你可以把它编译成模块
< > Kernel automounter support
<*> Kernel automounter version 4 support (also supports v3) <=== 我没有要挂载远程文件系统的需求
< > FUSE (Filesystem in Userspace) support
Caches --->
CD-ROM/DVD Filesystems --->
<> ISO 9660 CDROM file system support <=== 在虚拟机内，我不用CDROM
< > UDF file system support
DOS/FAT/NT Filesystems --->
< > MSDOS fs support <=== 我没有微软fs的设备
< > VFAT (Windows-95) fs support <=== 我没有微软fs的设备
< > NTFS file system support
Pseudo filesystems --->
[] Miscellaneous filesystems ---> <=== 如果你没有其他FS的支持需求，关
[] Network File Systems ---> <=== 如果你没有其他NFS的支持需求，关
Partition Types --->
[ ] Advanced partition selection <=== 如果不是和其他系统共存，可以不选
-*- Native language support ---> // 选上Chinese
Kernel hacking --->
[] Show timing information on printks <=== 在printk的输出中包含时间信息,可以用来分析内核启动过程各步骤所用时间 , 我不需要debug内核
[ ] Enable __deprecated logic
[*] Enable __must_check logic
(2048) Warn for stack frames larger than (needs gcc 4.4)
[] Magic SysRq key <=== 一种通过快捷键控制系统方式，除非你非常清楚这个选项，官方不推荐选择
[ ] Enable unused/obsolete exported symbols
-*- Debug Filesystem
[ ] Run 'make headers_check' when building vmlinux
[] Kernel debugging <=== 内核调试，关
[ ] Enable SLUB performance statistics
[] Compile the kernel with frame pointers <=== 还是跟内核开发有关
[ ] Delay each boot printk message by N milliseconds
< > torture tests for RCU
[ ] Check for stalled CPUs delaying RCU grace periods
< > Self test for the backtrace code
[ ] Force extended block device numbers and spread them
[ ] Fault-injection framework
[ ] Latency measuring infrastructure
[*] Sysctl checks
[] Tracers ---> <=== 内核跟踪分析器
[] Remote debugging over FireWire early on boot <=== 启动过程中，允许远程调试内核
[ ] Enable dynamic printk() support
[ ] Enable debugging of DMA-API usage
[ ] Sample kernel code --->
[ ] Filter access to /dev/mem
[] Enable verbose x86 bootup info messages <=== 在内核镜像解压缩阶段输出启动信息，关闭后相当于无声启动(Slient Bootup)
-*- Early printk
[] Early printk via EHCI debug port <=== 允许printk通过EHCI调试端口输出内核日志，调试的一律关
[ ] Use 4Kb for kernel stacks instead of 8Kb
[ ] Enable IOMMU stress-test mode
IO delay type (port 0x80 based port-IO delay [recommended]) --->
[*] Allow gcc to uninline functions marked 'inline'
Security options ---> <=== 安全特性，我选择全关，当然，这些选项不会影响你的日常开发，办公
[] Enable access key retention support <=== 关闭
[] Enable different security models <=== 关闭
[ ] Enable the securityfs filesystem
[] File POSIX Capabilities <=== 关闭
[ ] Integrity Measurement Architecture(IMA)
<*> Cryptographic API ---> // 加密API，这部分选项会根据此前的优化自动调整，默认即可
[] Virtualization ---> <=== 我的系统已经运行在虚拟机中，不需要再支持虚拟化
Library routines ---> // 库子程序，这部分选项会根据此前的优化自动调整，默认即可