diff options
| author | anton <anton@cvs.openbsd.org> | 2018-04-29 17:26:32 +0000 |
|---|---|---|
| committer | anton <anton@cvs.openbsd.org> | 2018-04-29 17:26:32 +0000 |
| commit | 00c3e3eff96c21ed0a1da1236708cd5ceb9326a2 (patch) | |
| tree | 190c4c1929265e97322c2c0a9c9c67f14dc04dc8 /sys/kern | |
| parent | 6e8b4c725a0dfa64bf09a5a64a9924697366be73 (diff) | |
In hash{free,init}(), there's no need to calculate the size of the hash table if
the given number of elements already is a power of 2.
ok visa@, "seems like a good plan" deraadt@
Diffstat (limited to 'sys/kern')
| -rw-r--r-- | sys/kern/kern_subr.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/sys/kern/kern_subr.c b/sys/kern/kern_subr.c index d46a9c410ce..1c333451def 100644 --- a/sys/kern/kern_subr.c +++ b/sys/kern/kern_subr.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kern_subr.c,v 1.49 2017/02/14 10:31:15 mpi Exp $ */ +/* $OpenBSD: kern_subr.c,v 1.50 2018/04/29 17:26:31 anton Exp $ */ /* $NetBSD: kern_subr.c,v 1.15 1996/04/09 17:21:56 ragge Exp $ */ /* @@ -163,8 +163,11 @@ hashinit(int elements, int type, int flags, u_long *hashmask) if (elements <= 0) panic("hashinit: bad cnt"); - for (hashsize = 1; hashsize < elements; hashsize <<= 1) - continue; + if ((elements & (elements - 1)) == 0) + hashsize = elements; + else + for (hashsize = 1; hashsize < elements; hashsize <<= 1) + continue; hashtbl = mallocarray(hashsize, sizeof(*hashtbl), type, flags); if (hashtbl == NULL) return NULL; @@ -182,8 +185,11 @@ hashfree(void *hash, int elements, int type) if (elements <= 0) panic("hashfree: bad cnt"); - for (hashsize = 1; hashsize < elements; hashsize <<= 1) - continue; + if ((elements & (elements - 1)) == 0) + hashsize = elements; + else + for (hashsize = 1; hashsize < elements; hashsize <<= 1) + continue; free(hashtbl, type, sizeof(*hashtbl) * hashsize); } |