我正在运行我的新电脑有8GB的内存安装，内存模块显示在BIOS屏幕和dmidecode，但总共只有4GB
/ proc / meminfo中只有4GB可见
uname -a Linux localhost 3.0.6-gentoo #2 SMP PREEMPT Sat Nov 19 10:45:22 GMT-- x86_64 AMD Phenom(tm) II X4 955 Processor AuthenticAMD GNU/Linux / proc / meminfo的结果如下:(谢谢Andrey）
MemTotal: 4021348 kB MemFree: 1440280 kB Buffers: 23696 kB Cached: 1710828 kB SwapCached: 4956 kB Active: 1389904 kB Inactive: 841364 kB Active(anon): 1337812 kB Inactive(anon): 714060 kB Active(file): 52092 kB Inactive(file): 127304 kB Unevictable: 32 kB Mlocked: 32 kB SwapTotal: 8388604 kB SwapFree: 8047900 kB Dirty: 0 kB Writeback: 0 kB AnonPages: 492732 kB Mapped: 47528 kB Shmem: 1555120 kB Slab: 267724 kB SReclaimable: 177464 kB SUnreclaim: 90260 kB KernelStack: 1176 kB PageTables: 12148 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 10399276 kB Committed_AS: 3293896 kB VmallocTotal: 34359738367 kB VmallocUsed: 317008 kB VmallocChunk: 34359398908 kB AnonHugePages: 120832 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB DirectMap4k: 23552 kB DirectMap2M: 3088384 kB DirectMap1G: 1048576 kB
我已经尝试使用mem = 8G作为内核启动参数，我读了一篇关于将HIGHMEM64G设置为yes的文章，然后才意识到只适用于32位内核。
尝试dmidecode -t内存
SMBIOS 2.7 present. Handle 0x0026, DMI type 16, 23 bytes Physical Memory Array Location: System Board Or Motherboard Use: System Memory Error Correction Type: Multi-bit ECC Maximum Capacity: 32 GB Error Information Handle: Not Provided Number Of Devices: 4 Handle 0x0028, DMI type 17, 34 bytes Memory Device Array Handle: 0x0026 Error Information Handle: Not Provided Total Width: 64 bits Data Width: 64 bits Size: 4096 MB Form Factor: DIMM Set: None Locator: DIMM0 Bank Locator: BANK0 Type: <OUT OF SPEC> Type Detail: Synchronous Speed: 1333 MHz Manufacturer: Manufacturer0 Serial Number: SerNum0 Asset Tag: AssetTagNum0 Part Number: Array1_PartNumber0 Rank: Unknown Handle 0x002A, DMI type 17, 34 bytes Memory Device Array Handle: 0x0026 Error Information Handle: Not Provided Total Width: Unknown Data Width: 64 bits Size: No Module Installed Form Factor: DIMM Set: None Locator: DIMM1 Bank Locator: BANK1 Type: Unknown Type Detail: Synchronous Speed: Unknown Manufacturer: Manufacturer1 Serial Number: SerNum1 Asset Tag: AssetTagNum1 Part Number: Array1_PartNumber1 Rank: Unknown Handle 0x002C, DMI type 17, 34 bytes Memory Device Array Handle: 0x0026 Error Information Handle: Not Provided Total Width: 64 bits Data Width: 64 bits Size: 4096 MB Form Factor: DIMM Set: None Locator: DIMM2 Bank Locator: BANK2 Type: <OUT OF SPEC> Type Detail: Synchronous Speed: 1333 MHz Manufacturer: Manufacturer2 Serial Number: SerNum2 Asset Tag: AssetTagNum2 Part Number: Array1_PartNumber2 Rank: Unknown Handle 0x002E, DMI type 17, 34 bytes Memory Device Array Handle: 0x0026 Error Information Handle: Not Provided Total Width: Unknown Data Width: 64 bits Size: No Module Installed Form Factor: DIMM Set: None Locator: DIMM3 Bank Locator: BANK3 Type: Unknown Type Detail: Synchronous Speed: Unknown Manufacturer: Manufacturer3 Serial Number: SerNum3 Asset Tag: AssetTagNum3 Part Number: Array1_PartNumber3 Rank: Unknown
我的主板是华硕M5 A99X EVO，有提到类似的问题在其他板上解决的火狐升级。 我正在使用最新的固件，似乎使问题变得更糟。
您可能已经激活了一些内存冗余function，如内存镜像 – 这减less了可用于O / S的RAM的数量。 某些BIOS还提供了一种兼容性模式（通常标记为“OS安装模式”），其中可见内存的总量被限制以解决安装程序错误 – 检查这一点。
进入BIOS，find一个名为“内存重新映射”的设置。 打开它。 否则，您的BIOS将按照32位操作系统预期的方式设置内存，并切断对4GB以上内存的访问。