From: Sergei Shtylyov <sergei.shtylyov@cogentembedded•com>
To: Oliver Hartkopp <socketcan@hartkopp•net>, linux-can@vger•kernel.org
Cc: netdev@vger•kernel.org
Subject: Re: [PATCH RFC v2 1/2] can: fix multiple delivery of a single CAN frame for overlapping CAN filters
Date: Mon, 30 Mar 2015 15:33:30 +0300 [thread overview]
Message-ID: <5519429A.8050000@cogentembedded.com> (raw)
In-Reply-To: <1427652564-32181-2-git-send-email-socketcan@hartkopp.net>
Hello.
On 3/29/2015 9:09 PM, Oliver Hartkopp wrote:
> The CAN_RAW socket can set multiple CAN identifier specific filters that lead
> to multiple filters in the af_can.c filter processing. These filters are
> indenpendent from each other which leads to logical OR'ed filters when applied.
> This patch makes sure that every CAN frame which is filtered for a specific
> socket is only delivered once to the user space. This is independent from the
> number of matching CAN filters of this socket.
> As the can_raw() function is executed from NET_RX softirq the introduced
> variables are implemented as per-CPU variables to avoid extensive locking at
> CAN frame reception time.
> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp•net>
> ---
> net/can/raw.c | 28 ++++++++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
> diff --git a/net/can/raw.c b/net/can/raw.c
> index 00c13ef..866a9b3 100644
> --- a/net/can/raw.c
> +++ b/net/can/raw.c
[...]
> @@ -123,6 +125,15 @@ static void raw_rcv(struct sk_buff *oskb, void *data)
> if (!ro->fd_frames && oskb->len != CAN_MTU)
> return;
>
> + /* eliminate multiple filter matches for the same skb */
> + if (*this_cpu_ptr(ro->uniq_skb) == oskb &&
> + ktime_equal(*this_cpu_ptr(ro->uniq_tstamp), oskb->tstamp)) {
> + return;
Over-indented.
> + } else {
> + *this_cpu_ptr(ro->uniq_skb) = oskb;
> + *this_cpu_ptr(ro->uniq_tstamp) = oskb->tstamp;
> + }
> +
> /* clone the given skb to be able to enqueue it into the rcv queue */
> skb = skb_clone(oskb, GFP_ATOMIC);
> if (!skb)
[...]
> @@ -297,6 +309,20 @@ static int raw_init(struct sock *sk)
> ro->recv_own_msgs = 0;
> ro->fd_frames = 0;
>
> + ro->uniq_skb = alloc_percpu(struct sk_buff *);
> + if (unlikely(ro->uniq_skb == NULL))
> + return -ENOMEM;
> + for_each_possible_cpu(cpu)
> + *per_cpu_ptr(ro->uniq_skb, cpu) = NULL;
> +
> + ro->uniq_tstamp = alloc_percpu(ktime_t);
> + if (unlikely(ro->uniq_tstamp == NULL)) {
!ro->uniq_tstamp is preferred in the networking code.
[...]
WBR, Sergei
next prev parent reply other threads:[~2015-03-30 12:33 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-29 18:09 [PATCH RFC v2 0/2] can: join filters with per-CPU variables Oliver Hartkopp
2015-03-29 18:09 ` [PATCH RFC v2 1/2] can: fix multiple delivery of a single CAN frame for overlapping CAN filters Oliver Hartkopp
2015-03-30 9:50 ` Marc Kleine-Budde
2015-03-30 10:29 ` Oliver Hartkopp
2015-03-30 10:36 ` Marc Kleine-Budde
2015-03-30 10:10 ` Marc Kleine-Budde
2015-03-30 10:16 ` Marc Kleine-Budde
2015-03-30 10:41 ` Oliver Hartkopp
2015-03-31 12:32 ` Marc Kleine-Budde
2015-03-31 20:24 ` Oliver Hartkopp
2015-03-30 12:33 ` Sergei Shtylyov [this message]
2015-03-30 15:49 ` Oliver Hartkopp
2015-03-30 17:14 ` Sergei Shtylyov
2015-03-30 17:25 ` Oliver Hartkopp
2015-03-29 18:09 ` [PATCH RFC v2 2/2] can: introduce new raw socket option to join the given " Oliver Hartkopp
2015-03-31 12:36 ` Marc Kleine-Budde
2015-03-31 20:30 ` Oliver Hartkopp
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