我有一台 32GB 和 64GB 的 Ryzen 5950x。在这两种情况下，Ubuntu 都报告少了 2-3GB。BIOS 是最新的。
如果能收回这 2-3GB 内存并好好利用它们就太好了。CPU 没有集成显卡。
total used free shared buff/cache available
Mem: 62Gi 9Gi 44Gi 6.0Mi 7.8Gi 52Gi
Swap: 0B 0B 0B
[ 0.062647] PM: hibernation: Registered nosave memory: [mem 0x00000000-0x00000fff]
[ 0.062649] PM: hibernation: Registered nosave memory: [mem 0x000a0000-0x000fffff]
[ 0.062650] PM: hibernation: Registered nosave memory: [mem 0x09d1f000-0x09ffffff]
[ 0.062651] PM: hibernation: Registered nosave memory: [mem 0x0a200000-0x0a20dfff]
[ 0.062652] PM: hibernation: Registered nosave memory: [mem 0x0b000000-0x0b01ffff]
[ 0.062653] PM: hibernation: Registered nosave memory: [mem 0x8f860000-0x8f860fff]
[ 0.062654] PM: hibernation: Registered nosave memory: [mem 0x8f86f000-0x8f86ffff]
[ 0.062655] PM: hibernation: Registered nosave memory: [mem 0x8f870000-0x8f870fff]
[ 0.062656] PM: hibernation: Registered nosave memory: [mem 0x8f88f000-0x8f88ffff]
[ 0.062657] PM: hibernation: Registered nosave memory: [mem 0xc3482000-0xc3482fff]
[ 0.062658] PM: hibernation: Registered nosave memory: [mem 0xc70bc000-0xc70c1fff]
[ 0.062659] PM: hibernation: Registered nosave memory: [mem 0xc8c52000-0xc8c52fff]
[ 0.062660] PM: hibernation: Registered nosave memory: [mem 0xca615000-0xcaa13fff]
[ 0.062661] PM: hibernation: Registered nosave memory: [mem 0xcaa14000-0xcabc4fff]
[ 0.062661] PM: hibernation: Registered nosave memory: [mem 0xcabc5000-0xcaefafff]
[ 0.062662] PM: hibernation: Registered nosave memory: [mem 0xcaefb000-0xcbbfefff]
[ 0.062663] PM: hibernation: Registered nosave memory: [mem 0xcd000000-0xcfffffff]
[ 0.062663] PM: hibernation: Registered nosave memory: [mem 0xd0000000-0xefffffff]
[ 0.062664] PM: hibernation: Registered nosave memory: [mem 0xf0000000-0xf7ffffff]
[ 0.062664] PM: hibernation: Registered nosave memory: [mem 0xf8000000-0xfd1fffff]
[ 0.062665] PM: hibernation: Registered nosave memory: [mem 0xfd200000-0xfd2fffff]
[ 0.062665] PM: hibernation: Registered nosave memory: [mem 0xfd300000-0xfd5fffff]
[ 0.062666] PM: hibernation: Registered nosave memory: [mem 0xfd600000-0xfd7fffff]
[ 0.062666] PM: hibernation: Registered nosave memory: [mem 0xfd800000-0xfe9fffff]
[ 0.062667] PM: hibernation: Registered nosave memory: [mem 0xfea00000-0xfea0ffff]
[ 0.062667] PM: hibernation: Registered nosave memory: [mem 0xfea10000-0xfeb7ffff]
[ 0.062668] PM: hibernation: Registered nosave memory: [mem 0xfeb80000-0xfec01fff]
[ 0.062668] PM: hibernation: Registered nosave memory: [mem 0xfec02000-0xfec0ffff]
[ 0.062669] PM: hibernation: Registered nosave memory: [mem 0xfec10000-0xfec10fff]
[ 0.062669] PM: hibernation: Registered nosave memory: [mem 0xfec11000-0xfec2ffff]
[ 0.062670] PM: hibernation: Registered nosave memory: [mem 0xfec30000-0xfec30fff]
[ 0.062670] PM: hibernation: Registered nosave memory: [mem 0xfec31000-0xfecfffff]
[ 0.062670] PM: hibernation: Registered nosave memory: [mem 0xfed00000-0xfed00fff]
[ 0.062671] PM: hibernation: Registered nosave memory: [mem 0xfed01000-0xfed3ffff]
[ 0.062671] PM: hibernation: Registered nosave memory: [mem 0xfed40000-0xfed44fff]
[ 0.062672] PM: hibernation: Registered nosave memory: [mem 0xfed45000-0xfed7ffff]
[ 0.062672] PM: hibernation: Registered nosave memory: [mem 0xfed80000-0xfed8ffff]
[ 0.062673] PM: hibernation: Registered nosave memory: [mem 0xfed90000-0xfedc1fff]
[ 0.062673] PM: hibernation: Registered nosave memory: [mem 0xfedc2000-0xfedcffff]
[ 0.062674] PM: hibernation: Registered nosave memory: [mem 0xfedd0000-0xfedd3fff]
[ 0.062674] PM: hibernation: Registered nosave memory: [mem 0xfedd4000-0xfedd5fff]
[ 0.062675] PM: hibernation: Registered nosave memory: [mem 0xfedd6000-0xfeffffff]
[ 0.062675] PM: hibernation: Registered nosave memory: [mem 0xff000000-0xffffffff]
只是猜测，这可能是为休眠/挂起保留的内存区域吗？如果是这样，我们可以禁用它吗？
我正在运行带有 5.11.0-22-generic 内核的 21.04。
谢谢！
答案1
大多数 Linux 操作系统以 Gibibytes 而不是 GB 来计算 RAM。我的 16GB 电脑只有 15.4GiB 左右的 RAM。RAM 是存在的，并且可用，但 GiB 更大，因此显示给您的数字较小（64GB 确实约为 62GiB）
答案2
我对此不是 100% 确定，但错误可能出在你的计算中。你看，GiB 不等于 GB。GiB 代表 Gibibyte，而 GB 代表 Gigabyte。64 GB 的 RAM 实际上约为 59 GiB。
对于较少的 RAM，这不会造成太大影响，但对于你的情况来说，确实如此。62GiB 实际上相当于 66GB。我猜额外的 2 GB 左右来自交换文件/分区