diff options
author | David Gibson <david@gibson.dropbear.id.au> | 2006-03-22 11:08:57 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-22 18:54:03 +0300 |
commit | 9da61aef0fd5b17dd4bf4baf33db12c470def774 (patch) | |
tree | cb4bb0b63c36a0b303ceadc0cec0fae00c49ecf3 | |
parent | 27a85ef1b81300cfff06b4c8037e9914dfb09acc (diff) | |
download | linux-9da61aef0fd5b17dd4bf4baf33db12c470def774.tar.xz |
[PATCH] hugepage: Fix hugepage logic in free_pgtables()
free_pgtables() has special logic to call hugetlb_free_pgd_range() instead
of the normal free_pgd_range() on hugepage VMAs. However, the test it uses
to do so is incorrect: it calls is_hugepage_only_range on a hugepage sized
range at the start of the vma. is_hugepage_only_range() will return true
if the given range has any intersection with a hugepage address region, and
in this case the given region need not be hugepage aligned. So, for
example, this test can return true if called on, say, a 4k VMA immediately
preceding a (nicely aligned) hugepage VMA.
At present we get away with this because the powerpc version of
hugetlb_free_pgd_range() is just a call to free_pgd_range(). On ia64 (the
only other arch with a non-trivial is_hugepage_only_range()) we get away
with it for a different reason; the hugepage area is not contiguous with
the rest of the user address space, and VMAs are not permitted in between,
so the test can't return a false positive there.
Nonetheless this should be fixed. We do that in the patch below by
replacing the is_hugepage_only_range() test with an explicit test of the
VMA using is_vm_hugetlb_page().
This in turn changes behaviour for platforms where is_hugepage_only_range()
returns false always (everything except powerpc and ia64). We address this
by ensuring that hugetlb_free_pgd_range() is defined to be identical to
free_pgd_range() (instead of a no-op) on everything except ia64. Even so,
it will prevent some otherwise possible coalescing of calls down to
free_pgd_range(). Since this only happens for hugepage VMAs, removing this
small optimization seems unlikely to cause any trouble.
This patch causes no regressions on the libhugetlbfs testsuite - ppc64
POWER5 (8-way), ppc64 G5 (2-way) and i386 Pentium M (UP).
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r-- | include/asm-ia64/page.h | 1 | ||||
-rw-r--r-- | include/asm-powerpc/pgtable.h | 5 | ||||
-rw-r--r-- | include/linux/hugetlb.h | 9 | ||||
-rw-r--r-- | mm/memory.c | 5 |
4 files changed, 8 insertions, 12 deletions
diff --git a/include/asm-ia64/page.h b/include/asm-ia64/page.h index 5e6362a786b7..732cf3086741 100644 --- a/include/asm-ia64/page.h +++ b/include/asm-ia64/page.h @@ -57,6 +57,7 @@ # define HAVE_ARCH_HUGETLB_UNMAPPED_AREA # define ARCH_HAS_HUGEPAGE_ONLY_RANGE +# define ARCH_HAS_HUGETLB_FREE_PGD_RANGE #endif /* CONFIG_HUGETLB_PAGE */ #ifdef __ASSEMBLY__ diff --git a/include/asm-powerpc/pgtable.h b/include/asm-powerpc/pgtable.h index e38931379a72..185ee15963a1 100644 --- a/include/asm-powerpc/pgtable.h +++ b/include/asm-powerpc/pgtable.h @@ -468,11 +468,6 @@ extern pgd_t swapper_pg_dir[]; extern void paging_init(void); -#ifdef CONFIG_HUGETLB_PAGE -#define hugetlb_free_pgd_range(tlb, addr, end, floor, ceiling) \ - free_pgd_range(tlb, addr, end, floor, ceiling) -#endif - /* * This gets called at the end of handling a page fault, when * the kernel has put a new PTE into the page table for the process. diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 5d84c368ffe4..e465fbf1ef5f 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -43,8 +43,10 @@ void hugetlb_change_protection(struct vm_area_struct *vma, #ifndef ARCH_HAS_HUGEPAGE_ONLY_RANGE #define is_hugepage_only_range(mm, addr, len) 0 -#define hugetlb_free_pgd_range(tlb, addr, end, floor, ceiling) \ - do { } while (0) +#endif + +#ifndef ARCH_HAS_HUGETLB_FREE_PGD_RANGE +#define hugetlb_free_pgd_range free_pgd_range #endif #ifndef ARCH_HAS_PREPARE_HUGEPAGE_RANGE @@ -93,8 +95,7 @@ static inline unsigned long hugetlb_total_pages(void) #define prepare_hugepage_range(addr, len) (-EINVAL) #define pmd_huge(x) 0 #define is_hugepage_only_range(mm, addr, len) 0 -#define hugetlb_free_pgd_range(tlb, addr, end, floor, ceiling) \ - do { } while (0) +#define hugetlb_free_pgd_range(tlb, addr, end, floor, ceiling) ({BUG(); 0; }) #define hugetlb_fault(mm, vma, addr, write) ({ BUG(); 0; }) #define hugetlb_change_protection(vma, address, end, newprot) diff --git a/mm/memory.c b/mm/memory.c index 71bc664efed5..f6e3be9cbf5a 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -277,7 +277,7 @@ void free_pgtables(struct mmu_gather **tlb, struct vm_area_struct *vma, anon_vma_unlink(vma); unlink_file_vma(vma); - if (is_hugepage_only_range(vma->vm_mm, addr, HPAGE_SIZE)) { + if (is_vm_hugetlb_page(vma)) { hugetlb_free_pgd_range(tlb, addr, vma->vm_end, floor, next? next->vm_start: ceiling); } else { @@ -285,8 +285,7 @@ void free_pgtables(struct mmu_gather **tlb, struct vm_area_struct *vma, * Optimization: gather nearby vmas into one call down */ while (next && next->vm_start <= vma->vm_end + PMD_SIZE - && !is_hugepage_only_range(vma->vm_mm, next->vm_start, - HPAGE_SIZE)) { + && !is_vm_hugetlb_page(vma)) { vma = next; next = vma->vm_next; anon_vma_unlink(vma); |