[PATCH net-next 1/6] bonding: verify if bond has ip only once on arp validate

[PATCH net-next 1/6] bonding: verify if bond has ip only once on arp validate

[Veaceslav Falico]

It's extra work to verify bond's ip presence for every slave, so take it
out of the loop.

Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
---
 drivers/net/bonding/bond_main.c |   13 ++++++++-----
 1 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index bc1246f..3d8b5ba 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2602,13 +2602,16 @@ static void bond_validate_arp(struct bonding *bond, struct slave *slave, __be32
 	int i;
 	__be32 *targets = bond->params.arp_targets;
 
+	if (!bond_has_this_ip(bond, tip)) {
+		pr_debug("bva: tip %pI4 not found\n", &tip);
+		return;
+	}
+
 	for (i = 0; (i < BOND_MAX_ARP_TARGETS) && targets[i]; i++) {
-		pr_debug("bva: sip %pI4 tip %pI4 t[%d] %pI4 bhti(tip) %d\n",
-			 &sip, &tip, i, &targets[i],
-			 bond_has_this_ip(bond, tip));
+		pr_debug("bva: sip %pI4 tip %pI4 t[%d] %pI4 bhti(tip)\n",
+			 &sip, &tip, i, &targets[i]);
 		if (sip == targets[i]) {
-			if (bond_has_this_ip(bond, tip))
-				slave->last_arp_rx = jiffies;
+			slave->last_arp_rx = jiffies;
 			return;
 		}
 	}
-- 
1.7.1

Re: [PATCH net-next 1/6] bonding: verify if bond has ip only once on arp validate

[Jay Vosburgh]

Veaceslav Falico <vfalico@redhat.com> wrote:

>It's extra work to verify bond's ip presence for every slave, so take it
>out of the loop.

	The current code doesn't verify for every slave (target address,
actually).  The call to bond_has_this_ip() happens at most once, if the
sip (source IP) matches the arp_ip_target being inspected, after which
the function returns.

	I can see that the patch will bypass the loop entirely if the
bond lacks the IP, but I'm not sure that's a meaningful improvement,
since it changes from calling bond_has_this_ip 0 or 1 times to always 1
time.

	-J


>Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
>---
> drivers/net/bonding/bond_main.c |   13 ++++++++-----
> 1 files changed, 8 insertions(+), 5 deletions(-)
>
>diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>index bc1246f..3d8b5ba 100644
>--- a/drivers/net/bonding/bond_main.c
>+++ b/drivers/net/bonding/bond_main.c
>@@ -2602,13 +2602,16 @@ static void bond_validate_arp(struct bonding *bond, struct slave *slave, __be32
> 	int i;
> 	__be32 *targets = bond->params.arp_targets;
>
>+	if (!bond_has_this_ip(bond, tip)) {
>+		pr_debug("bva: tip %pI4 not found\n", &tip);
>+		return;
>+	}
>+
> 	for (i = 0; (i < BOND_MAX_ARP_TARGETS) && targets[i]; i++) {
>-		pr_debug("bva: sip %pI4 tip %pI4 t[%d] %pI4 bhti(tip) %d\n",
>-			 &sip, &tip, i, &targets[i],
>-			 bond_has_this_ip(bond, tip));
>+		pr_debug("bva: sip %pI4 tip %pI4 t[%d] %pI4 bhti(tip)\n",
>+			 &sip, &tip, i, &targets[i]);
> 		if (sip == targets[i]) {
>-			if (bond_has_this_ip(bond, tip))
>-				slave->last_arp_rx = jiffies;
>+			slave->last_arp_rx = jiffies;
> 			return;
> 		}
> 	}
>-- 
>1.7.1
>

---
	-Jay Vosburgh, IBM Linux Technology Center, fubar@us.ibm.com

Re: [PATCH net-next 1/6] bonding: verify if bond has ip only once on arp validate

[Veaceslav Falico]

On Wed, Jun 19, 2013 at 10:50:24AM -0700, Jay Vosburgh wrote:
>Veaceslav Falico <vfalico@redhat.com> wrote:
>
>>It's extra work to verify bond's ip presence for every slave, so take it
>>out of the loop.
>
>	The current code doesn't verify for every slave (target address,
>actually).  The call to bond_has_this_ip() happens at most once, if the
>sip (source IP) matches the arp_ip_target being inspected, after which
>the function returns.
>
>	I can see that the patch will bypass the loop entirely if the
>bond lacks the IP, but I'm not sure that's a meaningful improvement,
>since it changes from calling bond_has_this_ip 0 or 1 times to always 1
>time.

Yep, you're right, I've misread the code.

It's just not worth it, will drop this patch in v2.

>
>	-J
>
>
>>Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
>>---
>> drivers/net/bonding/bond_main.c |   13 ++++++++-----
>> 1 files changed, 8 insertions(+), 5 deletions(-)
>>
>>diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>>index bc1246f..3d8b5ba 100644
>>--- a/drivers/net/bonding/bond_main.c
>>+++ b/drivers/net/bonding/bond_main.c
>>@@ -2602,13 +2602,16 @@ static void bond_validate_arp(struct bonding *bond, struct slave *slave, __be32
>> 	int i;
>> 	__be32 *targets = bond->params.arp_targets;
>>
>>+	if (!bond_has_this_ip(bond, tip)) {
>>+		pr_debug("bva: tip %pI4 not found\n", &tip);
>>+		return;
>>+	}
>>+
>> 	for (i = 0; (i < BOND_MAX_ARP_TARGETS) && targets[i]; i++) {
>>-		pr_debug("bva: sip %pI4 tip %pI4 t[%d] %pI4 bhti(tip) %d\n",
>>-			 &sip, &tip, i, &targets[i],
>>-			 bond_has_this_ip(bond, tip));
>>+		pr_debug("bva: sip %pI4 tip %pI4 t[%d] %pI4 bhti(tip)\n",
>>+			 &sip, &tip, i, &targets[i]);
>> 		if (sip == targets[i]) {
>>-			if (bond_has_this_ip(bond, tip))
>>-				slave->last_arp_rx = jiffies;
>>+			slave->last_arp_rx = jiffies;
>> 			return;
>> 		}
>> 	}
>>--
>>1.7.1
>>
>
>---
>	-Jay Vosburgh, IBM Linux Technology Center, fubar@us.ibm.com
>