From: Stephen Hemminger <stephen@networkplumber•org>
To: Nikolay Aleksandrov <nikolay@cumulusnetworks•com>
Cc: netdev@vger•kernel.org, roopa@cumulusnetworks•com,
bridge@lists•linux-foundation.org, davem@davemloft•net
Subject: [PATCH net-next] bridge: avoid unnecessary read of jiffies
Date: Tue, 7 Feb 2017 08:46:46 -0800 [thread overview]
Message-ID: <20170207084646.70dc888a@xeon-e3> (raw)
In-Reply-To: <1486227909-18319-5-git-send-email-nikolay@cumulusnetworks.com>
Jiffies is volatile so read it once.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft•com>
---
net/bridge/br_fdb.c | 6 ++++--
net/bridge/br_input.c | 6 ++++--
2 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index 5028691fa68a..5693168e88b6 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -592,13 +592,15 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
source->dev->name, addr, vid);
} else {
+ unsigned long now = jiffies;
+
/* fastpath: update of existing entry */
if (unlikely(source != fdb->dst)) {
fdb->dst = source;
fdb_modified = true;
}
- if (jiffies != fdb->updated)
- fdb->updated = jiffies;
+ if (now != fdb->updated)
+ fdb->updated = now;
if (unlikely(added_by_user))
fdb->added_by_user = 1;
if (unlikely(fdb_modified))
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 220943f920d2..4615a9b3e26c 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -195,11 +195,13 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
}
if (dst) {
+ unsigned long now = jiffies;
+
if (dst->is_local)
return br_pass_frame_up(skb);
- if (jiffies != dst->used)
- dst->used = jiffies;
+ if (now != dst->used)
+ dst->used = now;
br_forward(dst->dst, skb, local_rcv, false);
} else {
if (!mcast_hit)
--
2.11.0
next prev parent reply other threads:[~2017-02-07 16:46 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-04 17:05 [PATCH net-next 0/4] bridge: improve cache utilization Nikolay Aleksandrov via Bridge
2017-02-04 17:05 ` [PATCH net-next 1/4] bridge: modify bridge and port to have often accessed fields in one cache line Nikolay Aleksandrov
2017-02-04 17:05 ` [PATCH net-next 2/4] bridge: move to workqueue gc Nikolay Aleksandrov
2017-02-04 17:05 ` [PATCH net-next 3/4] bridge: move write-heavy fdb members in their own cache line Nikolay Aleksandrov
2017-02-04 17:05 ` [PATCH net-next 4/4] bridge: fdb: write to used and updated at most once per jiffy Nikolay Aleksandrov
2017-02-07 16:46 ` Stephen Hemminger [this message]
2017-02-07 16:56 ` [PATCH net-next] bridge: avoid unnecessary read of jiffies Nikolay Aleksandrov via Bridge
2017-02-07 19:16 ` David Miller
2017-02-04 21:46 ` [PATCH net-next 0/4] bridge: improve cache utilization Stephen Hemminger
2017-02-04 21:58 ` Nikolay Aleksandrov
2017-02-07 3:53 ` David Miller
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