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| author | alc <alc@FreeBSD.org> | 2013-05-11 18:01:41 +0000 |
|---|---|---|
| committer | alc <alc@FreeBSD.org> | 2013-05-11 18:01:41 +0000 |
| commit | 2435fdb8ad99091c1ae81a4064b25f19b3a85211 (patch) | |
| tree | 606551398b1ccf6d1b3771b7aebe40abf9577b76 /sys/vm/vm_radix.c | |
| parent | 4a8f8f585a9cf84fbb06924e9afd3c700b624833 (diff) | |
| download | FreeBSD-src-2435fdb8ad99091c1ae81a4064b25f19b3a85211.zip FreeBSD-src-2435fdb8ad99091c1ae81a4064b25f19b3a85211.tar.gz | |
To reduce the amount of arithmetic performed in the various radix tree
functions, reverse the numbering scheme for the levels. The highest
numbered level in the tree now appears near the root instead of the leaves.
Sponsored by: EMC / Isilon Storage Division
Diffstat (limited to 'sys/vm/vm_radix.c')
| -rw-r--r-- | sys/vm/vm_radix.c | 25 |
1 files changed, 12 insertions, 13 deletions
diff --git a/sys/vm/vm_radix.c b/sys/vm/vm_radix.c index c9710de..113a226 100644 --- a/sys/vm/vm_radix.c +++ b/sys/vm/vm_radix.c @@ -91,7 +91,7 @@ __FBSDID("$FreeBSD$"); /* Returns one unit associated with specified level. */ #define VM_RADIX_UNITLEVEL(lev) \ - ((vm_pindex_t)1 << ((VM_RADIX_LIMIT - (lev)) * VM_RADIX_WIDTH)) + ((vm_pindex_t)1 << ((lev) * VM_RADIX_WIDTH)) struct vm_radix_node { vm_pindex_t rn_owner; /* Owner of record. */ @@ -150,8 +150,7 @@ static __inline int vm_radix_slot(vm_pindex_t index, uint16_t level) { - return ((index >> ((VM_RADIX_LIMIT - level) * VM_RADIX_WIDTH)) & - VM_RADIX_MASK); + return ((index >> (level * VM_RADIX_WIDTH)) & VM_RADIX_MASK); } /* Trims the key after the specified level. */ @@ -161,9 +160,9 @@ vm_radix_trimkey(vm_pindex_t index, uint16_t level) vm_pindex_t ret; ret = index; - if (level < VM_RADIX_LIMIT) { - ret >>= (VM_RADIX_LIMIT - level) * VM_RADIX_WIDTH; - ret <<= (VM_RADIX_LIMIT - level) * VM_RADIX_WIDTH; + if (level > 0) { + ret >>= level * VM_RADIX_WIDTH; + ret <<= level * VM_RADIX_WIDTH; } return (ret); } @@ -234,7 +233,7 @@ vm_radix_keydiff(vm_pindex_t index1, vm_pindex_t index2) __func__, (uintmax_t)index1)); index1 ^= index2; - for (clev = 0;; clev++) + for (clev = VM_RADIX_LIMIT;; clev--) if (vm_radix_slot(index1, clev) != 0) return (clev); } @@ -247,8 +246,8 @@ static __inline boolean_t vm_radix_keybarr(struct vm_radix_node *rnode, vm_pindex_t idx) { - if (rnode->rn_clev > 0) { - idx = vm_radix_trimkey(idx, rnode->rn_clev - 1); + if (rnode->rn_clev < VM_RADIX_LIMIT) { + idx = vm_radix_trimkey(idx, rnode->rn_clev + 1); return (idx != rnode->rn_owner); } return (FALSE); @@ -384,7 +383,7 @@ vm_radix_insert(struct vm_radix *rtree, vm_page_t page) __func__, (uintmax_t)index); clev = vm_radix_keydiff(m->pindex, index); tmp = vm_radix_node_get(vm_radix_trimkey(index, - clev - 1), 2, clev); + clev + 1), 2, clev); *parentp = tmp; vm_radix_addpage(tmp, index, clev, page); vm_radix_addpage(tmp, m->pindex, clev, m); @@ -408,7 +407,7 @@ vm_radix_insert(struct vm_radix *rtree, vm_page_t page) */ newind = rnode->rn_owner; clev = vm_radix_keydiff(newind, index); - tmp = vm_radix_node_get(vm_radix_trimkey(index, clev - 1), 2, + tmp = vm_radix_node_get(vm_radix_trimkey(index, clev + 1), 2, clev); *parentp = tmp; vm_radix_addpage(tmp, index, clev, page); @@ -545,7 +544,7 @@ ascend: */ goto ascend; descend: - KASSERT(rnode->rn_clev < VM_RADIX_LIMIT, + KASSERT(rnode->rn_clev > 0, ("vm_radix_lookup_ge: pushing leaf's parent")); KASSERT(tos < VM_RADIX_LIMIT, ("vm_radix_lookup_ge: stack overflow")); @@ -658,7 +657,7 @@ ascend: */ goto ascend; descend: - KASSERT(rnode->rn_clev < VM_RADIX_LIMIT, + KASSERT(rnode->rn_clev > 0, ("vm_radix_lookup_le: pushing leaf's parent")); KASSERT(tos < VM_RADIX_LIMIT, ("vm_radix_lookup_le: stack overflow")); |
