From: Radu Rendec Date: Sun, 11 Nov 2007 05:54:50 +0000 (-0800) Subject: [PKT_SCHED] CLS_U32: Use ffs() instead of C code on hash mask to get first set bit. X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=b226801676d9533d09da511eb379fe970fa1a770;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git [PKT_SCHED] CLS_U32: Use ffs() instead of C code on hash mask to get first set bit. Computing the rank of the first set bit in the hash mask (for using later in u32_hash_fold()) was done with plain C code. Using ffs() instead makes the code more readable and improves performance (since ffs() is better optimized in assembler). Using the conditional operator on hash mask before applying ntohl() also saves one ntohl() call if mask is 0. Signed-off-by: Radu Rendec Signed-off-by: Jarek Poplawski Acked-by: Jamal Hadi Salim Signed-off-by: David S. Miller --- diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c index 53171029439f..c39008209164 100644 --- a/net/sched/cls_u32.c +++ b/net/sched/cls_u32.c @@ -613,17 +613,7 @@ static int u32_change(struct tcf_proto *tp, unsigned long base, u32 handle, memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key)); n->ht_up = ht; n->handle = handle; -{ - u8 i = 0; - u32 mask = ntohl(s->hmask); - if (mask) { - while (!(mask & 1)) { - i++; - mask>>=1; - } - } - n->fshift = i; -} + n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0; #ifdef CONFIG_CLS_U32_MARK if (tb[TCA_U32_MARK-1]) {