In the system call msync, it invokes filemap_sync inside. filemap_sync scans the Page Table entries corresponding to the linear address intervals included in the memory region. For each page found, it invokes flush_tlb_page() to flush the corresponding translation lookaside buffers, and marks the page as dirty.
Code:
int filemap_sync(struct vm_area_struct * vma, unsigned long address,
size_t size, unsigned int flags)
{
pgd_t * dir;
unsigned long end = address + size;
int error = 0;
spin_lock(&vma->vm_mm->page_table_lock);
dir = pgd_offset(vma->vm_mm, address);
flush_cache_range(vma->vm_mm, end - size, end);
if (address >= end)
BUG();
do {
error |= filemap_sync_pmd_range(dir, address, end - address, vma, flags);
address = (address + PGDIR_SIZE) & PGDIR_MASK;
dir++;
} while (address && (address < end));
flush_tlb_range(vma->vm_mm, end - size, end);
spin_unlock(&vma->vm_mm->page_table_lock);
return error;
}
If I want to make filemap_sync execute as long as possible, I'm wondering how can I do this in my user space code? Anything I can do to extend the length of its execution?
