From: Alexei Starovoitov <ast@plumgrid•com>
To: Eric Dumazet <eric.dumazet@gmail•com>
Cc: "David S. Miller" <davem@davemloft•net>,
Eric Dumazet <edumazet@google•com>,
Daniel Borkmann <daniel@iogearbox•net>,
Thomas Graf <tgraf@suug•ch>, Jamal Hadi Salim <jhs@mojatatu•com>,
John Fastabend <john.r.fastabend@intel•com>,
netdev@vger•kernel.org
Subject: Re: [PATCH RFC net-next] pktgen: introduce 'rx' mode
Date: Wed, 29 Apr 2015 16:59:49 -0700 [thread overview]
Message-ID: <55417075.9010601@plumgrid.com> (raw)
In-Reply-To: <1430350786.3711.77.camel@edumazet-glaptop2.roam.corp.google.com>
On 4/29/15 4:39 PM, Eric Dumazet wrote:
>
> Zap the 'burst/clone' thing, this is not going to work for RX.
> TX was okay, not RX.
>
> You could for instance do :
>
> atomic_inc(&skb->users);
> netif_receive_skb(skb);
> if (atomic_read(skb->users) != 1) {
> /* This is too bad, I can not recycle this skb because it is still used */
> consume_skb(skb);
> /* allocate a fresh new skb */
> skb = ...
> } else {
> /* Yeah ! Lets celebrate, cost of reusing this skb was one atomic op */
> }
ahh, great! I think I'm starting to understand.
then the following should be ok as well?
atomic_add(burst, &skb->users);
do {
netif_receive_skb(skb);
if (atomic_read(skb->users) != burst) {
/* too bad, can not recycle */
atomic_sub(burst - 1, &skb->users);
consume_skb(skb);
/* allocate a fresh new skb */
skb = ...
/* and get out of this loop */
} else {
/* Yeah ! the cost of reusing this skb was
one atomic op amortized over 'burst' iterations */
}
} while (--burst > 0);
next prev parent reply other threads:[~2015-04-29 23:59 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-29 2:11 [PATCH RFC net-next] netif_receive_skb performance Alexei Starovoitov
2015-04-29 2:11 ` [PATCH RFC net-next] pktgen: introduce 'rx' mode Alexei Starovoitov
2015-04-29 4:14 ` Eric Dumazet
2015-04-29 21:55 ` Alexei Starovoitov
2015-04-29 22:19 ` Eric Dumazet
2015-04-29 22:38 ` Alexei Starovoitov
2015-04-29 22:56 ` Eric Dumazet
2015-04-29 23:28 ` Alexei Starovoitov
2015-04-29 23:39 ` Eric Dumazet
2015-04-29 23:59 ` Alexei Starovoitov [this message]
2015-04-29 5:23 ` [PATCH RFC net-next] netif_receive_skb performance Eric Dumazet
2015-04-29 22:15 ` Alexei Starovoitov
2015-04-29 9:37 ` Daniel Borkmann
2015-04-29 22:20 ` Alexei Starovoitov
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