User data within the process address space must be accessed using kernel services.

对于进程地址空间中的用户数据，必须使用内核服务进行访问。

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If the allocation of parts of either memory or disk space have been exhausted before a calculation process is complete, your user will get an error message that memory or disk space has run out.

如果在计算处理完成之前，内存或磁盘空间的块分配已经耗尽，用户就会看到内存或磁盘空间用完的错误消息。

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The two biggest drawbacks to KVM are that it requires newer virtualization-capable processors and a user-space QEMU process to provide I/O virtualization.

KVM 两个最大的缺点是需要较新的能够支持虚拟化的处理器，以及一个用户空间的 QEMU 进程来提供 I/O 虚拟化。

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