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authorDavid Gibson <david@gibson.dropbear.id.au>2006-03-22 00:08:57 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-22 07:54:03 -0800
commit9da61aef0fd5b17dd4bf4baf33db12c470def774 (patch)
treecb4bb0b63c36a0b303ceadc0cec0fae00c49ecf3 /include/linux/hugetlb.h
parent27a85ef1b81300cfff06b4c8037e9914dfb09acc (diff)
downloadop-kernel-dev-9da61aef0fd5b17dd4bf4baf33db12c470def774.zip
op-kernel-dev-9da61aef0fd5b17dd4bf4baf33db12c470def774.tar.gz
[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>
Diffstat (limited to 'include/linux/hugetlb.h')
-rw-r--r--include/linux/hugetlb.h9
1 files changed, 5 insertions, 4 deletions
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 5d84c36..e465fbf 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)
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