linux 2.6.16.38 w/ vs2.0.3-rc1

[linux-2.6.git] / arch / x86_64 / mm / pageattr.c

diff --git a/arch/x86_64/mm/pageattr.c b/arch/x86_64/mm/pageattr.c
index 2685b1f..35f1f1a 100644 (file)
--- a/arch/x86_64/mm/pageattr.c
+++ b/arch/x86_64/mm/pageattr.c
@@ -3,6 +3,7 @@
  * Thanks to Ben LaHaise for precious feedback.
  */ 
 
+#include <linux/config.h>
 #include <linux/mm.h>
 #include <linux/sched.h>
 #include <linux/highmem.h>
@@ -44,13 +45,6 @@ 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);
@@ -83,12 +77,26 @@ static inline void flush_map(unsigned long address)
        on_each_cpu(flush_kernel_map, (void *)address, 1, 1);
 }
 
-static struct page *deferred_pages; /* protected by init_mm.mmap_sem */
+struct deferred_page { 
+       struct deferred_page *next; 
+       struct page *fpage;
+       unsigned long address;
+}; 
+static struct deferred_page *df_list; /* protected by init_mm.mmap_sem */
 
-static inline void save_page(struct page *fpage)
+static inline void save_page(unsigned long address, struct page *fpage)
 {
-       fpage->lru.next = (struct list_head *)deferred_pages;
-       deferred_pages = fpage;
+       struct deferred_page *df;
+       df = kmalloc(sizeof(struct deferred_page), GFP_KERNEL); 
+       if (!df) {
+               flush_map(address);
+               __free_page(fpage);
+       } else { 
+               df->next = df_list;
+               df->fpage = fpage;
+               df->address = address;
+               df_list = df;
+       }                       
 }
 
 /* 
@@ -130,8 +138,8 @@ __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;
@@ -143,20 +151,23 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
                        set_pte(kpte,mk_pte(split, ref_prot2));
                        kpte_page = split;
                }       
-               page_private(kpte_page)++;
+               get_page(kpte_page);
        } else if ((kpte_flags & _PAGE_PSE) == 0) { 
                set_pte(kpte, pfn_pte(pfn, ref_prot));
-               BUG_ON(page_private(kpte_page) == 0);
-               page_private(kpte_page)--;
+               __put_page(kpte_page);
        } else
                BUG();
 
        /* on x86-64 the direct mapping set at boot is not using 4k pages */
        BUG_ON(PageReserved(kpte_page));
 
-       if (page_private(kpte_page) == 0) {
-               save_page(kpte_page);
+       switch (page_count(kpte_page)) {
+       case 1:
+               save_page(address, kpte_page);               
                revert_page(address, ref_prot);
+               break;
+       case 0:
+               BUG(); /* memleak and failed 2M page regeneration */
        }
        return 0;
 } 
@@ -209,18 +220,17 @@ int change_page_attr(struct page *page, int numpages, pgprot_t prot)
 
 void global_flush_tlb(void)
 { 
-       struct page *dpage;
+       struct deferred_page *df, *next_df;
 
        down_read(&init_mm.mmap_sem);
-       dpage = xchg(&deferred_pages, NULL);
+       df = xchg(&df_list, NULL);
        up_read(&init_mm.mmap_sem);
-
-       flush_map((dpage && !dpage->lru.next) ? (unsigned long)page_address(dpage) : 0);
-       while (dpage) {
-               struct page *tmp = dpage;
-               dpage = (struct page *)dpage->lru.next;
-               ClearPagePrivate(tmp);
-               __free_page(tmp);
+       flush_map((df && !df->next) ? df->address : 0);
+       for (; df; df = next_df) { 
+               next_df = df->next;
+               if (df->fpage) 
+                       __free_page(df->fpage);
+               kfree(df);
        } 
 }