From: Eric Dumazet <eric.dumazet@gmail•com>
To: Neil Horman <nhorman@tuxdriver•com>
Cc: netdev@vger•kernel.org, davem@davemloft•net, socketcan@hartkopp•net
Subject: Re: [PATCH] Generalize socket rx gap / receive queue overflow cmsg (v3)
Date: Sat, 10 Oct 2009 06:59:53 +0200 [thread overview]
Message-ID: <4AD014C9.2010801@gmail.com> (raw)
In-Reply-To: <20091009235631.GA31501@hmsreliant.think-freely.org>
Neil Horman a écrit :
> Ok, take 3 with Erics new notes
>
> Change Notes:
>
> 1) Modified inlining of sock_recv_ts_and_drops to be more efficient
>
> 2) modify getsockopt for SO_RXQ_OVFL to gurantee only a 1 or 0 return
>
> =============================================================
>
>
> Create a new socket level option to report number of queue overflows
>
> Recently I augmented the AF_PACKET protocol to report the number of frames lost
> on the socket receive queue between any two enqueued frames. This value was
> exported via a SOL_PACKET level cmsg. AFter I completed that work it was
> requested that this feature be generalized so that any datagram oriented socket
> could make use of this option. As such I've created this patch, It creates a
> new SOL_SOCKET level option called SO_RXQ_OVFL, which when enabled exports a
> SOL_SOCKET level cmsg that reports the nubmer of times the sk_receive_queue
> overflowed between any two given frames. It also augments the AF_PACKET
> protocol to take advantage of this new feature (as it previously did not touch
> sk->sk_drops, which this patch uses to record the overflow count). Tested
> successfully by me.
>
> Notes:
>
> 1) Unlike my previous patch, this patch simply records the sk_drops value, which
> is not a number of drops between packets, but rather a total number of drops.
> Deltas must be computed in user space.
>
> 2) While this patch currently works with datagram oriented protocols, it will
> also be accepted by non-datagram oriented protocols. I'm not sure if thats
> agreeable to everyone, but my argument in favor of doing so is that, for those
> protocols which aren't applicable to this option, sk_drops will always be zero,
> and reporting no drops on a receive queue that isn't used for those
> non-participating protocols seems reasonable to me. This also saves us having
> to code in a per-protocol opt in mechanism.
>
> 3) This applies cleanly to net-next assuming that commit
> 977750076d98c7ff6cbda51858bb5a5894a9d9ab (my af packet cmsg patch) is reverted
>
> Signed-off-by: Neil Horman <nhorman@tuxdriver•com>
I read your patch and found one error (at the very end)
Feel free to resubmit with my
Signed-off-by: Eric Dumazet <eric.dumazet@gmail•com>
>
> +inline void sock_recv_drops(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
> +{
> + if (sock_flag(sk, SOCK_RXQ_OVFL) && skb && skb->dropcount)
> + put_cmsg(msg, SOL_SOCKET, SO_RXQ_OVFL,
> + sizeof(__u32), &skb->dropcount);
> +}
> +
> +void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
> + struct sk_buff *skb)
> +{
> + sock_recv_timestamp(msg, sk, skb);
> + sock_recv_drops(msg, sk, skb);
> + put_cmsg(msg, SOL_SOCKET, SO_RXQ_OVFL, sizeof(__u32), &skb->dropcount);
It's already part of sock_recv_drops()
> +}
> +EXPORT_SYMBOL_GPL(sock_recv_ts_and_drops);
> +
next prev parent reply other threads:[~2009-10-10 5:00 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-07 18:08 [PATCH] Generalize socket rx gap / receive queue overflow cmsg Neil Horman
2009-10-08 1:05 ` Eric Dumazet
2009-10-08 13:54 ` Neil Horman
2009-10-08 14:45 ` Eric Dumazet
2009-10-08 17:20 ` Neil Horman
2009-10-09 19:35 ` [PATCH] Generalize socket rx gap / receive queue overflow cmsg (v2) Neil Horman
2009-10-09 21:31 ` Eric Dumazet
2009-10-09 23:21 ` Neil Horman
2009-10-09 23:56 ` [PATCH] Generalize socket rx gap / receive queue overflow cmsg (v3) Neil Horman
2009-10-10 4:59 ` Eric Dumazet [this message]
2009-10-10 5:12 ` Eric Dumazet
2009-10-10 12:35 ` [PATCH] Generalize socket rx gap / receive queue overflow cmsg (v4) Neil Horman
2009-10-12 4:38 ` Eric Dumazet
2009-10-12 5:48 ` Oliver Hartkopp
2009-10-12 10:01 ` David Miller
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