> For the complete documentation index, see [llms.txt](https://book.bsdcn.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://book.bsdcn.org/man/man9/pmap_page_exists_quick.9.md). # pmap\_page\_exists\_quick.9 `pmap_page_exists_quick` — 确定页面是否存在于物理映射中 ## 名称 `pmap_page_exists_quick` ## 概要 `#include ` `#include ` `#include ` `Ft bool Fn pmap_page_exists_quick pmap_t pmap vm_page_t m` ## 描述 `pmap_page_exists_quick` 函数用于快速确定页面 `m` 是否存在于物理映射 `pmap` 中。通常从 VM 分页代码中调用。 ## 实现说明 上述使用的 PV 计数将来可能向上或向下调整；只需为 pmap 的一小部分子集返回 `true` 即可正确进行页面老化。 ## 返回值 仅当物理映射 `pmap` 的 PV 条目是从页面 `m` 链接的前 16 个 PV 之一时，`pmap_page_exists_quick` 才返回 `true`。 ## 参见 [pmap(9)](/man/man9/pmap.9.md) ## 作者 本手册页由 Bruce M Simpson 编写。 --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://book.bsdcn.org/man/man9/pmap_page_exists_quick.9.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.