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author | David Gibson <david@gibson.dropbear.id.au> | 2006-03-22 11:08:57 +0300 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-22 18:54:03 +0300 |
commit | 9da61aef0fd5b17dd4bf4baf33db12c470def774 (patch) | |
tree | cb4bb0b63c36a0b303ceadc0cec0fae00c49ecf3 /include/asm-powerpc | |
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>
Diffstat (limited to 'include/asm-powerpc')
-rw-r--r-- | include/asm-powerpc/pgtable.h | 5 |
1 files changed, 0 insertions, 5 deletions
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. |