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authorIngo Molnar <mingo@elte.hu>2008-01-30 13:33:57 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-30 13:33:57 +0100
commit9a3dc7804e9856668caef41efc54179e61ffccc0 (patch)
treea4f154ce7ad556fb5677e154b45747479694482b
parent7afe15b9d888050435cd154906828df88d4e667d (diff)
x86: cpa: simplify locking
further simplify cpa locking: since the largepage-split is a slowpath, use the pgd_lock for the whole operation, intead of the mmap_sem. This also makes it suitable for DEBUG_PAGEALLOC purposes again. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--arch/x86/mm/pageattr_32.c12
1 files changed, 5 insertions, 7 deletions
diff --git a/arch/x86/mm/pageattr_32.c b/arch/x86/mm/pageattr_32.c
index 0966023dfd7..9cf2fea54eb 100644
--- a/arch/x86/mm/pageattr_32.c
+++ b/arch/x86/mm/pageattr_32.c
@@ -37,9 +37,8 @@ pte_t *lookup_address(unsigned long address, int *level)
return pte_offset_kernel(pmd, address);
}
-static void set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
+static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
{
- unsigned long flags;
struct page *page;
/* change init_mm */
@@ -47,7 +46,6 @@ static void set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
if (SHARED_KERNEL_PMD)
return;
- spin_lock_irqsave(&pgd_lock, flags);
for (page = pgd_list; page; page = (struct page *)page->index) {
pgd_t *pgd;
pud_t *pud;
@@ -58,12 +56,12 @@ static void set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
pmd = pmd_offset(pud, address);
set_pte_atomic((pte_t *)pmd, pte);
}
- spin_unlock_irqrestore(&pgd_lock, flags);
}
static int split_large_page(pte_t *kpte, unsigned long address)
{
pgprot_t ref_prot = pte_pgprot(pte_clrhuge(*kpte));
+ unsigned long flags;
unsigned long addr;
pte_t *pbase, *tmp;
struct page *base;
@@ -73,7 +71,7 @@ static int split_large_page(pte_t *kpte, unsigned long address)
if (!base)
return -ENOMEM;
- down_write(&init_mm.mmap_sem);
+ spin_lock_irqsave(&pgd_lock, flags);
/*
* Check for races, another CPU might have split this page
* up for us already:
@@ -95,11 +93,11 @@ static int split_large_page(pte_t *kpte, unsigned long address)
/*
* Install the new, split up pagetable:
*/
- set_pmd_pte(kpte, address, mk_pte(base, ref_prot));
+ __set_pmd_pte(kpte, address, mk_pte(base, ref_prot));
base = NULL;
out_unlock:
- up_write(&init_mm.mmap_sem);
+ spin_unlock_irqrestore(&pgd_lock, flags);
if (base)
__free_pages(base, 0);