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| author | Keir Fraser <keir.fraser@citrix.com> | 2009-09-22 08:18:19 +0100 |
|---|---|---|
| committer | Keir Fraser <keir.fraser@citrix.com> | 2009-09-22 08:18:19 +0100 |
| commit | 73f0173619a0017225fc185ed1a96a1a47a8a0c3 (patch) | |
| tree | 1945ed1c64da29298248b7aa3e6fcaf2a1dafa54 /xen/include/asm-x86/mm.h | |
| parent | bac2000063ba239d33b631f6edda48cc6b57425b (diff) | |
| download | xen-73f0173619a0017225fc185ed1a96a1a47a8a0c3.tar.gz xen-73f0173619a0017225fc185ed1a96a1a47a8a0c3.tar.bz2 xen-73f0173619a0017225fc185ed1a96a1a47a8a0c3.zip | |
x86: map frame table sparsely
Avoid backing frame table holes with memory, when those holes are
large enough to cover an exact multiple of large pages. This is based
on the introduction of a bit map, where each bit represents one such
range, thus allowing mfn_valid() checks to easily filter out those
MFNs that now shouldn't be used to index the frame table.
This allows for saving a couple of 2M pages even on "normal" systems.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Diffstat (limited to 'xen/include/asm-x86/mm.h')
| -rw-r--r-- | xen/include/asm-x86/mm.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h index f8c1e01313..c569573446 100644 --- a/xen/include/asm-x86/mm.h +++ b/xen/include/asm-x86/mm.h @@ -263,6 +263,10 @@ extern unsigned long max_page; extern unsigned long total_pages; void init_frametable(void); +#define PDX_GROUP_COUNT ((1 << L2_PAGETABLE_SHIFT) / \ + (sizeof(*frame_table) & -sizeof(*frame_table))) +extern unsigned long pdx_group_valid[]; + /* Convert between Xen-heap virtual addresses and page-info structures. */ static inline struct page_info *__virt_to_page(const void *v) { |