diff mbox series

[net-next] vxlan: reduce dirty cache line in vxlan_find_mac

Message ID 1534649768-24074-1-git-send-email-lirongqing@baidu.com
State Deferred, archived
Delegated to: David Miller
Headers show
Series [net-next] vxlan: reduce dirty cache line in vxlan_find_mac | expand

Commit Message

Li RongQing Aug. 19, 2018, 3:36 a.m. UTC 
vxlan_find_mac() unconditionally set f->used for every packet,
this cause a cache miss for every packet, since remote, hlist
and used of vxlan_fdb share the same cacheline.

With this change f->used is set only if not equal to jiffies
This gives up to 5% speed-up with small packets.

Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
---
 drivers/net/vxlan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

David Miller Aug. 19, 2018, 6:11 p.m. UTC | #1 
From: Li RongQing <lirongqing@baidu.com>
Date: Sun, 19 Aug 2018 11:36:08 +0800

> vxlan_find_mac() unconditionally set f->used for every packet,
> this cause a cache miss for every packet, since remote, hlist
> and used of vxlan_fdb share the same cacheline.
> 
> With this change f->used is set only if not equal to jiffies
> This gives up to 5% speed-up with small packets.
> 
> Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
> Signed-off-by: Li RongQing <lirongqing@baidu.com>

Please resubmit this when the net-next tree opens back up.

Thanks.
diff mbox series

Patch

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index ababba37d735..e5d236595206 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -464,7 +464,7 @@  static struct vxlan_fdb *vxlan_find_mac(struct vxlan_dev *vxlan,
 	struct vxlan_fdb *f;
 
 	f = __vxlan_find_mac(vxlan, mac, vni);
-	if (f)
+	if (f && f->used != jiffies)
 		f->used = jiffies;
 
 	return f;