Using /proc/[pid]/pagemap

linux process proc
HH- Apologize to Carole Baskin picture HH- Apologize to Carole Baskin · Feb 20, 2014 · Viewed 10.4k times · Source

I am aware that there is a little information regarding the pagemap file here. But nobody seems to indicate how to reference entries in the file. Is it offset by virtual address? Can I take a virtual address VA and simply lseek to offset VA? Or is it by page? If so, how do I retrieve the page number, as maps simply lists them in order. I am trying to translate between virtual and physical addresses, and lseek'ing with the virtual address as the offset always returns the same number, no matter where I seek to.

Thanks

@leeduhem: Yes I have. Here's the relevant part: 3. Open /proc/pid/pagemap and seek to the pages you would like to examine. 4. Read a u64 for each page from pagemap.

That doesn't help me. It wants me to seek to the page, but how do I know where the entry for the page is?

Answer

Dmitry picture Dmitry · Mar 1, 2014

There is a tool that will help you to get information you need from the pagemap file.

http://fivelinesofcode.blogspot.com/2014/03/how-to-translate-virtual-to-physical.html

Related questions

How can I measure the actual memory usage of an application or process?

This question is covered here in great detail. How do you measure the memory usage of an application or process in Linux? From the blog article of Understanding memory usage on Linux, ps is not an accurate tool to use …

Read More
What killed my process and why?

My application runs as a background process on Linux. It is currently started at the command line in a Terminal window. Recently a user was executing the application for a while and it died mysteriously. The text: Killed was on …

Read More
What's the best way to send a signal to all members of a process group?

I want to kill a whole process tree. What is the best way to do this using any common scripting languages? I am looking for a simple solution.

Read More