[PATCH] x86_64: pageattr remove __put_page

Remove page_count and __put_page from x86-64 pageattr

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 14 insertions, 9 deletions

diff --git a/arch/x86_64/mm/pageattr.c b/arch/x86_64/mm/pageattr.c
index efe5af14c7db..531ad21447b1 100644
--- a/arch/x86_64/mm/pageattr.c
+++ b/arch/x86_64/mm/pageattr.c
@@ -45,6 +45,13 @@ static struct page *split_large_page(unsigned long address, pgprot_t prot,
         pte_t *pbase;
         if (!base) 
                 return NULL;
+        /*
+         * page_private is used to track the number of entries in
+         * the page table page have non standard attributes.
+         */
+        SetPagePrivate(base);
+        page_private(base) = 0;
+
         address = __pa(address);
         addr = address & LARGE_PAGE_MASK; 
         pbase = (pte_t *)page_address(base);
@@ -124,8 +131,8 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
                         set_pte(kpte, pfn_pte(pfn, prot));
                 } else {
                         /*
-                         * split_large_page will take the reference for this change_page_attr
-                         * on the split page.
+                         * split_large_page will take the reference for this
+                         * change_page_attr on the split page.
                          */
 
                         struct page *split;
@@ -137,23 +144,20 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
                         set_pte(kpte,mk_pte(split, ref_prot2));
                         kpte_page = split;
                 }       
-                get_page(kpte_page);
+                page_private(kpte_page)++;
         } else if ((kpte_flags & _PAGE_PSE) == 0) { 
                 set_pte(kpte, pfn_pte(pfn, ref_prot));
-                __put_page(kpte_page);
+                BUG_ON(page_private(kpte_page) == 0);
+                page_private(kpte_page)--;
         } else
                 BUG();
 
         /* on x86-64 the direct mapping set at boot is not using 4k pages */
         BUG_ON(PageReserved(kpte_page));
 
-        switch (page_count(kpte_page)) {
-        case 1:
+        if (page_private(kpte_page) == 0) {
                 save_page(kpte_page);
                 revert_page(address, ref_prot);
-                break;
-        case 0:
-                BUG(); /* memleak and failed 2M page regeneration */
         }
         return 0;
 } 
@@ -216,6 +220,7 @@ void global_flush_tlb(void)
         while (dpage) {
                 struct page *tmp = dpage;
                 dpage = (struct page *)dpage->lru.next;
+                ClearPagePrivate(tmp);
                 __free_page(tmp);
         } 
 }