如何导致 TLB 与用户进程发生冲突？
我目前的工作需要在Intel Core系列的CPU上生成指定数量的TLB未命中，但进展并不顺利。我尝试了很多方法，但它们的 TLB 命中率都很高。有谁知道有关 x86 TLB 如何工作的一些有用信息，或者在用户进程中生成大量 TLB 未命中的方法？
My current work needs to generate a specified number of TLB misses on CPU of Intel Core series, while it's not going on well. I've tried many methods but all of them have a very high rate of TLB hit. Does anyone know some useful information about how x86 TLB works, or some method to generate large number of TLB misses within a user process?
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TLB 是 CPU 用来记住与虚拟地址关联的物理地址的高速缓存。虚拟地址空间被分成页，通常每页 4KB。 TLB 为每个可能的虚拟页都有一个空间，其中包含与其关联的物理页的地址。当您尝试访问物理地址尚未加载的页面时，就会发生 TLB 未命中。因此，为了最大限度地提高未命中率，您需要最大限度地提高访问的不同页面的数量。
不幸的是，事情并没有那么简单。简单的 TLB 未命中将从页表层次结构中读取条目以找到正确的物理地址。但这仅在您访问具有物理地址的页面时才会发生。操作系统将确定哪些虚拟地址具有哪些物理地址，如果您尝试从任何其他地址读取数据，则会导致页面错误。页面错误处理程序将终止非法访问该页面的程序，或者移动数据以将物理页面放入该虚拟地址中。
导致尽可能多的 TLB 未命中的最佳方法是：
当可用 RAM 变低时，未命中次数将会增加，因为操作系统必须移动更多物理页来满足程序的需求，因此最好同时运行其他占用内存的进程。
The TLB is a cache used by the CPU to remember the physical address associated with a virtual address. The virtual address space is split into pages, usually 4KB each. The TLB has a space for each possible virtual page which contains the address of the physical page associated with it. A TLB miss occurs when you try to access a page whose physical address has not been loaded yet. Therefore, to maximize misses, you need to maximize the number of different pages accessed.
Unfortunately, it is not that simple. A simple TLB miss would read entries from the page table hierarchy to find the proper physical address. But this only occurs if you access a page which has a physical address. The OS will determine what virtual addresses have what physical addresses, and if you try to read from any others, you will cause a page fault. The page fault handler will either terminate your program for illegally accessing that page or move data around to put a physical page in that virtual address.
The best way to cause as many TLB misses as possible is to:
The number of misses will go up as available RAM gets low, because the OS will have to move more physical pages around to satisfy your program's needs, so it is good to have other, memory hungry processes running at the same time.