* [PATCH][net-next] vxlan: reduce dirty cache line in vxlan_find_mac
@ 2018-08-19 3:36 Li RongQing
2018-08-19 18:11 ` David Miller
0 siblings, 1 reply; 4+ messages in thread
From: Li RongQing @ 2018-08-19 3:36 UTC (permalink / raw)
To: netdev
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(-)
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;
--
2.16.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH][net-next] vxlan: reduce dirty cache line in vxlan_find_mac
2018-08-19 3:36 [PATCH][net-next] vxlan: reduce dirty cache line in vxlan_find_mac Li RongQing
@ 2018-08-19 18:11 ` David Miller
0 siblings, 0 replies; 4+ messages in thread
From: David Miller @ 2018-08-19 18:11 UTC (permalink / raw)
To: lirongqing; +Cc: netdev
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.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH][net-next] vxlan: reduce dirty cache line in vxlan_find_mac
@ 2018-08-29 3:52 Li RongQing
2018-08-30 5:08 ` David Miller
0 siblings, 1 reply; 4+ messages in thread
From: Li RongQing @ 2018-08-29 3:52 UTC (permalink / raw)
To: netdev
vxlan_find_mac() unconditionally set f->used for every packet,
this causes a cache miss for every packet, since remote, hlist
and used of vxlan_fdb share the same cache line, which are
accessed when send every packets.
so f->used is set only if not equal to jiffies, to reduce dirty
cache line times, this gives 3% 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(-)
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;
--
2.16.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH][net-next] vxlan: reduce dirty cache line in vxlan_find_mac
2018-08-29 3:52 Li RongQing
@ 2018-08-30 5:08 ` David Miller
0 siblings, 0 replies; 4+ messages in thread
From: David Miller @ 2018-08-30 5:08 UTC (permalink / raw)
To: lirongqing; +Cc: netdev
From: Li RongQing <lirongqing@baidu.com>
Date: Wed, 29 Aug 2018 11:52:10 +0800
> vxlan_find_mac() unconditionally set f->used for every packet,
> this causes a cache miss for every packet, since remote, hlist
> and used of vxlan_fdb share the same cache line, which are
> accessed when send every packets.
>
> so f->used is set only if not equal to jiffies, to reduce dirty
> cache line times, this gives 3% speed-up with small packets.
>
> Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
> Signed-off-by: Li RongQing <lirongqing@baidu.com>
Applied.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2018-08-30 9:09 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2018-08-19 3:36 [PATCH][net-next] vxlan: reduce dirty cache line in vxlan_find_mac Li RongQing
2018-08-19 18:11 ` David Miller
-- strict thread matches above, loose matches on Subject: below --
2018-08-29 3:52 Li RongQing
2018-08-30 5:08 ` David Miller
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).