Some Questions about Kernel Page Table

lichangshou chungzhou at
Thu Jan 6 22:40:20 EST 2011

Hi all,

In linux-, the page size of kernel image is 2M, which means that the
entity in pmd is PFN pointing to physical page.
For research, I want to change the page size of kernel image to 4K. I
modified the content of pmd to make each entity of pmd point to a new page
Here is the my related code:
 542         pte = alloc_low_page(&pte_phys);   // allocate a new page for
page table
 544         last_map_addr = phys_pte_init_remap(pte, address, end,
new_prot);  // initiate the entity of new page table
 545         unmap_low_page(pte);
 547         spin_lock(&init_mm.page_table_lock);
 548         pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));  // modify
this pmd entiity, make it point to the address of new page table.
 550         spin_unlock(&init_mm.page_table_lock);
After adding those code to kernel source, I test the new complied kernel,
but the kernel always reboot and can't work.
Thinking long time, I can't fix where the bug is.
Any suggestions for me?

-------------- next part --------------
An HTML attachment was scrubbed...

More information about the Kernelnewbies mailing list