Merge branch 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc

[sfrench/cifs-2.6.git] / arch / x86 / mm / init_32.c

diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index ee1091a469641f95db2564c558827e972728ee37..9ec62da85fd79a75fc450b58c4ea54e4c77f857b 100644 (file)
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -1,5 +1,4 @@
 /*
- *  linux/arch/i386/mm/init.c
  *
  *  Copyright (C) 1995  Linus Torvalds
  *
@@ -51,6 +50,8 @@
 
 unsigned int __VMALLOC_RESERVE = 128 << 20;
 
+unsigned long max_pfn_mapped;
+
 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
 unsigned long highstart_pfn, highend_pfn;
 
@@ -179,8 +180,13 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base)
                        /*
                         * Map with big pages if possible, otherwise
                         * create normal page tables:
+                        *
+                        * Don't use a large page for the first 2/4MB of memory
+                        * because there are often fixed size MTRRs in there
+                        * and overlapping MTRRs into large pages can cause
+                        * slowdowns.
                         */
-                       if (cpu_has_pse) {
+                       if (cpu_has_pse && !(pgd_idx == 0 && pmd_idx == 0)) {
                                unsigned int addr2;
                                pgprot_t prot = PAGE_KERNEL_LARGE;
 
@@ -194,6 +200,7 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base)
                                set_pmd(pmd, pfn_pmd(pfn, prot));
 
                                pfn += PTRS_PER_PTE;
+                               max_pfn_mapped = pfn;
                                continue;
                        }
                        pte = one_page_table_init(pmd);
@@ -208,6 +215,7 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base)
 
                                set_pte(pte, pfn_pte(pfn, prot));
                        }
+                       max_pfn_mapped = pfn;
                }
        }
 }
@@ -723,25 +731,17 @@ void mark_rodata_ro(void)
        unsigned long start = PFN_ALIGN(_text);
        unsigned long size = PFN_ALIGN(_etext) - start;
 
-#ifndef CONFIG_KPROBES
-#ifdef CONFIG_HOTPLUG_CPU
-       /* It must still be possible to apply SMP alternatives. */
-       if (num_possible_cpus() <= 1)
-#endif
-       {
-               set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
-               printk(KERN_INFO "Write protecting the kernel text: %luk\n",
-                       size >> 10);
+       set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
+       printk(KERN_INFO "Write protecting the kernel text: %luk\n",
+               size >> 10);
 
 #ifdef CONFIG_CPA_DEBUG
-               printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
-                       start, start+size);
-               set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT);
+       printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
+               start, start+size);
+       set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT);
 
-               printk(KERN_INFO "Testing CPA: write protecting again\n");
-               set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
-#endif
-       }
+       printk(KERN_INFO "Testing CPA: write protecting again\n");
+       set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
 #endif
        start += size;
        size = (unsigned long)__end_rodata - start;