diff options
| author | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:33:57 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:33:57 +0100 |
| commit | 9a3dc7804e9856668caef41efc54179e61ffccc0 (patch) | |
| tree | a4f154ce7ad556fb5677e154b45747479694482b | |
| parent | 7afe15b9d888050435cd154906828df88d4e667d (diff) | |
| download | linux-9a3dc7804e9856668caef41efc54179e61ffccc0.tar.bz2 | |
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.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/arch/x86/mm/pageattr_32.c b/arch/x86/mm/pageattr_32.c index 0966023dfd70..9cf2fea54eb5 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); |