From: David Laight <David.Laight@ACULAB.COM>
To: 'Xie He' <xie.he.0141@gmail.com>, Julian Wiedmann <jwi@linux.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Linux X25 <linux-x25@vger.kernel.org>,
Linux Kernel Network Developers <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
"Martin Schiller" <ms@dev.tdt.de>
Subject: RE: [PATCH net] net: lapb: Copy the skb before sending a packet
Date: Tue, 2 Feb 2021 09:04:07 +0000 [thread overview]
Message-ID: <6da2329e69d247daac6c6d7d442f0e38@AcuMS.aculab.com> (raw)
In-Reply-To: <CAJht_EOw4d9h7LqOsXpucADV5=gAGws-fKj5q7BdH2+h0Yv9Vg@mail.gmail.com>
From: Xie He
> Sent: 01 February 2021 16:15
>
> On Mon, Feb 1, 2021 at 6:10 AM Julian Wiedmann <jwi@linux.ibm.com> wrote:
> >
> > This sounds a bit like you want skb_cow_head() ... ?
>
> Calling "skb_cow_head" before we call "skb_clone" would indeed solve
> the problem of writes to our clones affecting clones in other parts of
> the system. But since we are still writing to the skb after
> "skb_clone", it'd still be better to replace "skb_clone" with
> "skb_copy" to avoid interference between our own clones.
What is the fastest link lapb is actually used on these days?
64k used to be 'fast' - so copying the skb isn't going to have
a noticeable effect on system performance.
We did once get a 'free' upgrade of our X.25 link from 2400 to 9600.
Probably due to the power consumption and rack space needed for
the older modem.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2021-02-02 9:12 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-01 5:57 [PATCH net] net: lapb: Copy the skb before sending a packet Xie He
2021-02-01 10:05 ` Martin Schiller
2021-02-01 10:49 ` Xie He
2021-02-01 12:47 ` Martin Schiller
2021-02-01 14:10 ` Julian Wiedmann
2021-02-01 16:14 ` Xie He
2021-02-02 4:42 ` Jakub Kicinski
2021-02-02 6:25 ` Xie He
2021-02-02 16:41 ` Jakub Kicinski
2021-02-02 9:04 ` David Laight [this message]
2021-02-02 16:50 ` patchwork-bot+netdevbpf
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