Update 'confirmed' timestamp when ARP packet is received. It shouldn't
affect locktime logic and anyway entry can be confirmed by any higher-layer
protocol. Thus it makes to sense not to confirm it when ARP packet is
received.
Fixes: 77d7123342 ("neighbour: update neigh timestamps iff update is
effective")
Signed-off-by: Vasily Khoruzhick <[email protected]>
---
v2: - update comment to match new code.
net/core/neighbour.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index aa19d86937af..56a554597db5 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1180,6 +1180,12 @@ int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
lladdr = neigh->ha;
}
+ /* Update confirmed timestamp for neighbour entry after we
+ * received ARP packet even if it doesn't change IP to MAC binding.
+ */
+ if (new & NUD_CONNECTED)
+ neigh->confirmed = jiffies;
+
/* If entry was valid and address is not changed,
do not change entry state, if new one is STALE.
*/
@@ -1201,15 +1207,12 @@ int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
}
}
- /* Update timestamps only once we know we will make a change to the
+ /* Update timestamp only once we know we will make a change to the
* neighbour entry. Otherwise we risk to move the locktime window with
* noop updates and ignore relevant ARP updates.
*/
- if (new != old || lladdr != neigh->ha) {
- if (new & NUD_CONNECTED)
- neigh->confirmed = jiffies;
+ if (new != old || lladdr != neigh->ha)
neigh->updated = jiffies;
- }
if (new != old) {
neigh_del_timer(neigh);
--
2.18.0
On Tue, 11 Sep 2018 11:04:06 -0700
Vasily Khoruzhick <[email protected]> wrote:
> diff --git a/net/core/neighbour.c b/net/core/neighbour.c
> index aa19d86937af..56a554597db5 100644
> --- a/net/core/neighbour.c
> +++ b/net/core/neighbour.c
> @@ -1180,6 +1180,12 @@ int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
> lladdr = neigh->ha;
> }
>
> + /* Update confirmed timestamp for neighbour entry after we
> + * received ARP packet even if it doesn't change IP to MAC binding.
> + */
> + if (new & NUD_CONNECTED)
> + neigh->confirmed = jiffies;
You might want to do:
if ((new & NUD_CONNECTED) && neigh->confirmed != jiffies)
neigh->confirmed = jiffies;
This avoid poisoning the cacheline with unnecessary write.
On Tue, Sep 11, 2018 at 11:12 AM, Stephen Hemminger
<[email protected]> wrote:
> On Tue, 11 Sep 2018 11:04:06 -0700
> Vasily Khoruzhick <[email protected]> wrote:
>
>> diff --git a/net/core/neighbour.c b/net/core/neighbour.c
>> index aa19d86937af..56a554597db5 100644
>> --- a/net/core/neighbour.c
>> +++ b/net/core/neighbour.c
>> @@ -1180,6 +1180,12 @@ int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
>> lladdr = neigh->ha;
>> }
>>
>> + /* Update confirmed timestamp for neighbour entry after we
>> + * received ARP packet even if it doesn't change IP to MAC binding.
>> + */
>> + if (new & NUD_CONNECTED)
>> + neigh->confirmed = jiffies;
>
> You might want to do:
> if ((new & NUD_CONNECTED) && neigh->confirmed != jiffies)
> neigh->confirmed = jiffies;
>
> This avoid poisoning the cacheline with unnecessary write.
Sorry for duplicate - this time in plain text, so it should get
through lkml filter:
I don't think that it's performance-critical path, so this
optimization is unnecessary
and it doesn't improve code readability.
Hello!
On 9/11/2018 9:04 PM, Vasily Khoruzhick wrote:
> Update 'confirmed' timestamp when ARP packet is received. It shouldn't
> affect locktime logic and anyway entry can be confirmed by any higher-layer
> protocol. Thus it makes to sense not to confirm it when ARP packet is
"Makes sense" or "makes no sense"?
> received.
>
> Fixes: 77d7123342 ("neighbour: update neigh timestamps iff update is
> effective")
>
> Signed-off-by: Vasily Khoruzhick <[email protected]>
[...]
MBR, Sergei
From: Vasily Khoruzhick <[email protected]>
Date: Tue, 11 Sep 2018 11:04:06 -0700
> Update 'confirmed' timestamp when ARP packet is received. It shouldn't
> affect locktime logic and anyway entry can be confirmed by any higher-layer
> protocol. Thus it makes to sense not to confirm it when ARP packet is
> received.
>
> Fixes: 77d7123342 ("neighbour: update neigh timestamps iff update is
> effective")
>
> Signed-off-by: Vasily Khoruzhick <[email protected]>
> ---
> v2: - update comment to match new code.
Please fix the wording in this commit message, as per Sergei's
feedback.
Also, the Fixes: tag should be all one line (people grep for these
strings in the repository) and with no empty lines between it and the
rest of the tags such as Signed-off-by:
Thanks.