diff options
| author | alc <alc@FreeBSD.org> | 2013-04-22 01:26:13 +0000 |
|---|---|---|
| committer | alc <alc@FreeBSD.org> | 2013-04-22 01:26:13 +0000 |
| commit | 78339bf7f3a0cd62b1bcf122e6ca71e724ee1df9 (patch) | |
| tree | 03018f70bdac68afc57149ded58e443775166c5e /sys/vm/vm_radix.c | |
| parent | 136b9108c6d50b6ad751df685c7892070d641e2e (diff) | |
| download | FreeBSD-src-78339bf7f3a0cd62b1bcf122e6ca71e724ee1df9.zip FreeBSD-src-78339bf7f3a0cd62b1bcf122e6ca71e724ee1df9.tar.gz | |
Simplify vm_radix_{add,dec}lev().
Sponsored by: EMC / Isilon Storage Division
Diffstat (limited to 'sys/vm/vm_radix.c')
| -rw-r--r-- | sys/vm/vm_radix.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/sys/vm/vm_radix.c b/sys/vm/vm_radix.c index 970bc66..10ecff3 100644 --- a/sys/vm/vm_radix.c +++ b/sys/vm/vm_radix.c @@ -265,16 +265,19 @@ vm_radix_keybarr(struct vm_radix_node *rnode, vm_pindex_t idx) static __inline int vm_radix_addlev(vm_pindex_t *idx, boolean_t *levels, uint16_t ilev) { - vm_pindex_t wrapidx; for (; levels[ilev] == FALSE || vm_radix_slot(*idx, ilev) == (VM_RADIX_COUNT - 1); ilev--) if (ilev == 0) return (1); - wrapidx = *idx; + + /* + * The following computation cannot overflow because *idx's slot at + * ilev is less than VM_RADIX_COUNT - 1. + */ *idx = vm_radix_trimkey(*idx, ilev); *idx += VM_RADIX_UNITLEVEL(ilev); - return (*idx < wrapidx); + return (0); } /* @@ -286,17 +289,19 @@ vm_radix_addlev(vm_pindex_t *idx, boolean_t *levels, uint16_t ilev) static __inline int vm_radix_declev(vm_pindex_t *idx, boolean_t *levels, uint16_t ilev) { - vm_pindex_t wrapidx; for (; levels[ilev] == FALSE || vm_radix_slot(*idx, ilev) == 0; ilev--) if (ilev == 0) return (1); - wrapidx = *idx; + + /* + * The following computation cannot overflow because *idx's slot at + * ilev is greater than 0. + */ *idx = vm_radix_trimkey(*idx, ilev); - *idx |= VM_RADIX_UNITLEVEL(ilev) - 1; - *idx -= VM_RADIX_UNITLEVEL(ilev); - return (*idx > wrapidx); + *idx -= 1; + return (0); } /* |
