From: "Michael S. Tsirkin" <mst@redhat.com>
To: Ian Campbell <Ian.Campbell@citrix.com>
Cc: David Miller <davem@davemloft.net>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"eric.dumazet@gmail.com" <eric.dumazet@gmail.com>
Subject: Re: [PATCH RFC 1/6] skbuff: support per-page destructors in copy_ubufs
Date: Fri, 11 May 2012 19:30:58 +0300 [thread overview]
Message-ID: <20120511163057.GB10344@redhat.com> (raw)
In-Reply-To: <20120511120836.GA4637@redhat.com>
On Fri, May 11, 2012 at 03:08:36PM +0300, Michael S. Tsirkin wrote:
> On Fri, May 11, 2012 at 11:58:12AM +0100, Ian Campbell wrote:
> > On Fri, 2012-05-11 at 10:00 +0100, Ian Campbell wrote:
> > > I'm seeing copy_ubufs called in my remote NFS test, which I don't
> > > think I expected -- I'll investigate why this is happening today.
> >
> > It's tcp_transmit_skb which can (conditionally) call skb_clone
> > (backtrace below)
>
> Interesting. I didn't realise we clone skbs on data path:
> tcp_write_xmit calls tcp_transmit_skb with clone_it flag.
> Could someone comment on why we need to clone on good path
> like this?
Hmm, it's in case we need to retransmit it later.
> --
> MST
next prev parent reply other threads:[~2012-05-11 18:30 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-07 13:53 [PATCH RFC 0/6] copy aside frags with destructors (was [PATCH 7/9] net: add skb_orphan_frags to copy aside frags with destructors) Michael S. Tsirkin
2012-05-07 13:54 ` [PATCH RFC 1/6] skbuff: support per-page destructors in copy_ubufs Michael S. Tsirkin
2012-05-10 17:46 ` Ian Campbell
2012-05-10 18:42 ` Michael S. Tsirkin
2012-05-11 9:00 ` Ian Campbell
2012-05-11 10:58 ` Ian Campbell
2012-05-11 12:08 ` Michael S. Tsirkin
2012-05-11 16:30 ` Michael S. Tsirkin [this message]
2012-05-12 6:01 ` Ian Campbell
2012-05-13 10:10 ` Michael S. Tsirkin
2012-05-11 21:12 ` David Miller
2012-05-07 13:54 ` [PATCH RFC 2/6] skbuff: add an api to orphan frags Michael S. Tsirkin
2012-05-08 12:47 ` Michael S. Tsirkin
2012-05-07 13:54 ` [PATCH RFC 3/6] skbuff: convert to skb_orphan_frags Michael S. Tsirkin
2012-05-07 13:54 ` [PATCH RFC 4/6] tun: orphan frags on xmit Michael S. Tsirkin
2012-05-08 14:36 ` Michael S. Tsirkin
2012-05-07 13:54 ` [PATCH RFC 5/6] net: orphan frags on receive Michael S. Tsirkin
2012-05-09 13:54 ` Ian Campbell
2012-05-09 15:12 ` Michael S. Tsirkin
2012-05-14 19:18 ` Michael S. Tsirkin
2012-05-07 13:54 ` [PATCH RFC 6/6] skbuff: set zerocopy flag on frag destructor Michael S. Tsirkin
2012-05-08 12:46 ` Michael S. Tsirkin
2012-05-08 9:41 ` [PATCH RFC 0/6] copy aside frags with destructors (was [PATCH 7/9] net: add skb_orphan_frags to copy aside frags with destructors) Michael S. Tsirkin
2012-05-08 10:54 ` Ian Campbell
2012-05-08 14:49 ` Michael S. Tsirkin
2012-05-09 13:18 ` Ian Campbell
2012-05-09 13:52 ` Michael S. Tsirkin
2012-05-09 14:01 ` Ian Campbell
2012-05-09 15:27 ` Michael S. Tsirkin
2012-05-09 14:56 ` Michael S. Tsirkin
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