major page fault handler in Linux kernel
kernel, linux, linux-kernel, page-fault
Solution
The `handle_mm_fault` function handles the page fault. Its return value is a set of flags. if `VM_FAULT_MAJOR` is set, then it's a major page fault. The kernel calls `perf_sw_event(PERF_COUNT_SW_PAGE_FAULT_MAJ, 1, 0, ...` on every major page fault.
Problem
I am wondering where is the major page fault handler. I wrote an algorithm to minimize page faults in the kernel. So I need to record something whenever a page fault happens. I currently record a page fault happen at do_page_fault(...) in arch/x86/mm/fault_32.c However, it seems both minor and major page fault will go to do_page_fault(...) ... And minor page faults happen all the time and messed up the algorithm. I guess I only want to record stuff when a major page_fault happens. So, kernel hackers, would you please tell me where should I put my code? Which file and which function. By the way, I am hacking kernel 2.6.24 Thank you very much! Alfred