From: Eric Dumazet <dada1@cosmosbay.com>
Date: Fri, 21 Dec 2007 09:49:07 +0000 (-0800)
Subject: [INET]: Avoid an integer divide in rt_garbage_collect()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=b790cedd24a7f7d1639072b3faf35f1f56cb38ea;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

[INET]: Avoid an integer divide in rt_garbage_collect()

Since 'goal' is a signed int, compiler may emit an integer divide
to compute goal/2.

Using a right shift is OK here and less expensive.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 1cc6c23cf758..933b093721ea 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -851,14 +851,14 @@ static int rt_garbage_collect(void)
 			equilibrium = ipv4_dst_ops.gc_thresh;
 		goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
 		if (goal > 0) {
-			equilibrium += min_t(unsigned int, goal / 2, rt_hash_mask + 1);
+			equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
 			goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
 		}
 	} else {
 		/* We are in dangerous area. Try to reduce cache really
 		 * aggressively.
 		 */
-		goal = max_t(unsigned int, goal / 2, rt_hash_mask + 1);
+		goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
 		equilibrium = atomic_read(&ipv4_dst_ops.entries) - goal;
 	}