On Wed, Jan 04, 2017 at 10:37:58AM +0530, Aneesh Kumar K.V wrote:
Reza Arbab <ar...@linux.vnet.ibm.com> writes:
+static void remove_pagetable(unsigned long start, unsigned long end)
+{
+       unsigned long addr, next;
+       pud_t *pud_base;
+       pgd_t *pgd;
+
+       spin_lock(&init_mm.page_table_lock);
+
+       for (addr = start; addr < end; addr = next) {
+               next = pgd_addr_end(addr, end);
+
+               pgd = pgd_offset_k(addr);
+               if (!pgd_present(*pgd))
+                       continue;
+
+               if (pgd_huge(*pgd)) {
+                       pte_clear(&init_mm, addr, (pte_t *)pgd);
+                       continue;
+               }
+
+               pud_base = (pud_t *)pgd_page_vaddr(*pgd);
+               remove_pud_table(pud_base, addr, next);
+               free_pud_table(pud_base, pgd);
+       }
+
+       spin_unlock(&init_mm.page_table_lock);

What is this lock protecting ?

The more I look into it, I'm not sure. This is still an artifact from the x86 functions, where they lock/unlock agressively, as you and Ben noted. I can take it out.
+       flush_tlb_kernel_range(start, end);

We can use radix__flush_tlb_kernel_range avoiding an if
(radix_enabled()) conditional ?

Yes, good idea.

(radix_enabled()) conditional ? Also if needed we could make all the
above take a radix__ prefix ?

You mean rename all these new functions? We could, but I don't really see why. These functions are static to pgtable-radix.c, there aren't hash__ versions to differentiate from, and it seemed helpful to mirror the x86 names.

--
Reza Arbab

Reply via email to